A/C acting up

03 1500 5.3 My a/c seems to be acting up. I have had in the past month where it works intermittenly, or wrks but then blows warm when I park outside/non driving but keep the motor runs, it literally feels like air temperature out of the ducts.
So today 88 air temp, I get 41 and 205 AT 2000RPM on the gauges and the duct air temp is 49.5 deg and about 47 at 2000rpm. I dont really see a difference in pressures when I rev the car. I have about 135,000 miles on the truck.
Time for a new compressor??

03 1500 5.3 My a/c seems to be acting up. I have had in the past month where it works intermittenly, or wrks but then blows warm when I park outside/non driving but keep the motor runs, it literally feels like air temperature out of the ducts.
So today 88 air temp, I get 41 and 205 AT 2000RPM on the gauges and the duct air temp is 49.5 deg and about 47 at 2000rpm. I dont really see a difference in pressures when I rev the car. I have about 135,000 miles on the truck.
Time for a new compressor??

I think you need slightly more refrigerent. 205 is low ..should be up around 280 psi when its 90 deg f air temp..

I think you need slightly more refrigerent. 205 is low ..should be up around 280 psi when its 90 deg f air temp..

Should I be ok with just adding a full can and see what that does? How can I tell from just being low or a real compressor problem?

Should I be ok with just adding a full can and see what that does? How can I tell from just being low or a real compressor problem?

you add with the 85-90 deg f air temp until the high side rises to the 280 psi area..as long as you are below 325psi with doors open blower on max you will be in the safe range...don't use the whole can if it is not necessary.. could be close to full 12 oz but my guess is slightly less..

post back how it went..

you add with the 85-90 deg f air temp until the high side rises to the 280 psi area..as long as you are below 325psi with doors open blower on max you will be in the safe range...don't use the whole can if it is not necessary.. could be close to full 12 oz but my guess is slightly less..

post back how it went..


I added a full can that didnt help to raise my pressures. So I spent the day changing the compressor/drier/accumulator, orifice tube and flushing the lines and refill. I am back where I started, 34low 220-235 high at 88 deg. Vent temp is 48 at idle and whats weird is that my vent temp gets cooler at lower rpms it appears, coldest I can get for a split second is 45 degrees. Now what.... when I flushed the lines everything seemed good and clear, orifice tube had one small spec of black rubber so I dont think the old compressor was even bad. Could the condensor just be real dirty? Could my lights in the front of the truck be blocking the air at the condensor?

I added a full can that didnt help to raise my pressures. So I spent the day changing the compressor/drier/accumulator, orifice tube and flushing the lines and refill. I am back where I started, 34low 220-235 high at 88 deg. Vent temp is 48 at idle and whats weird is that my vent temp gets cooler at lower rpms it appears, coldest I can get for a split second is 45 degrees. Now what.... when I flushed the lines everything seemed good and clear, orifice tube had one small spec of black rubber so I dont think the old compressor was even bad. Could the condensor just be real dirty? Could my lights in the front of the truck be blocking the air at the condensor?

220 psi/235 psi is more than the 205 psi you stated earlier. add more refrigerent until it gets to the 300psi area at 90 degf with the doors open and the engine at 1500-2000rpm..

running at engine idle rpm of 500, doors closed is a useless test with these ac units..

if the condenser was dirty you would have high pressures on the high side///.//could be the evap is plugged with dirt you have a cabin filter replaced lately ?????

220 psi/235 psi is more than the 205 psi you stated earlier. add more refrigerent until it gets to the 300psi area at 90 degf with the doors open and the engine at 1500-2000rpm..

running at engine idle rpm of 500, doors closed is a useless test with these ac units..

if the condenser was dirty you would have high pressures on the high side///.//could be the evap is plugged with dirt you have a cabin filter replaced lately ?????

I thought my truck doesnt have a cabin filter? Where is it? I looked once and thought I read that the 03 didnt have a filter. I actually probably have more refrigerant than the truck calls for, I put in almost 4 cans trying to get the pressure up! Whats weird is sometimes, even today I turn the air on and get nothing, blows hot air. Turn it off and back on and then it works again. Could this intermittent workng be related to my pressure issue?

I thought my truck doesnt have a cabin filter? Where is it? I looked once and thought I read that the 03 didnt have a filter. I actually probably have more refrigerant than the truck calls for, I put in almost 4 cans trying to get the pressure up! Whats weird is sometimes, even today I turn the air on and get nothing, blows hot air. Turn it off and back on and then it works again. Could this intermittent workng be related to my pressure issue?

the slippage of the compressor clutch could explain this. check the gap ..could be it needs to be pushed closer to the pully..or it may need cleaning because of oil and /or dirt on the surface of the clutch pulley face..

I have a cabin air filter[2000 silv] ..you should have one also ..these usually in our region need replacing or cleaning every 2 yrs max...sometimes more often..

this is a 2 piece filter side by side under and behind the glove box next to those blower resistors that fail..

remove the cover of the air box passengerside. you will see a 1 inch vertical slot/cover with a screw holding that will be hard to get ..remove the srew and pop off the cover..if you see no filters then you will most likely have to remove the dash to get at those evap coils to clean..you can try to vac out the mess with small made up vac hoses that will fit.

throwing out these filters rather than replacing is done to save the 20.oo for replaCements then you get your type issue ..

if the evap can not pick up the heat the high side pressures will be low..also poor cooling..

DIRT BLOCKING THE EVAP COIL !

if this is what you find recheck the pressures if you find the high side is to high then slowly bleed off excess refrigerent so at 90 deg f you have no more than 325 psi with the proper testing operations I have described earlier..

the slippage of the compressor clutch could explain this. check the gap ..could be it needs to be pushed closer to the pully..or it may need cleaning because of oil and /or dirt on the surface of the clutch pulley face..

I have a cabin air filter[2000 silv] ..you should have one also ..these usually in our region need replacing or cleaning every 2 yrs max...sometimes more often..

this is a 2 piece filter side by side under and behind the glove box next to those blower resistors that fail..

remove the cover of the air box passengerside. you will see a 1 inch vertical slot/cover with a screw holding that will be hard to get ..remove the srew and pop off the cover..if you see no filters then you will most likely have to remove the dash to get at those evap coils to clean..you can try to vac out the mess with small made up vac hoses that will fit.

throwing out these filters rather than replacing is done to save the 20.oo for replaCements then you get your type issue ..

if the evap can not pick up the heat the high side pressures will be low..also poor cooling..

DIRT BLOCKING THE EVAP COIL !

if this is what you find recheck the pressures if you find the high side is to high then slowly bleed off excess refrigerent so at 90 deg f you have no more than 325 psi with the proper testing operations I have described earlier..

I know I have checked for a filter once and didnt find one! I bought the truck with 65000 miles on it. Maybe someone took it out and never replaced it? But the filter I got at the time didnt fit the slot. Do you have any pics of the location?

I know I have checked for a filter once and didnt find one! I bought the truck with 65000 miles on it. Maybe someone took it out and never replaced it? But the filter I got at the time didnt fit the slot. Do you have any pics of the location?

http://www.youtube.com/watch?v=L37x4b35L8U

I know I have checked for a filter once and didnt find one! I bought the truck with 65000 miles on it. Maybe someone took it out and never replaced it? But the filter I got at the time didnt fit the slot. Do you have any pics of the location?

I think yours is a one piece filter..my vehicle is two pieces...

I think yours is a one piece filter..my vehicle is two pieces...

I checked, my box is sealed, no screws...pics attached....

I checked, my box is sealed, no screws...pics attached....

Here are more pics

Here are more pics


I see your filter cover is horizontal about 8 inches long 1 inch wide right next to the connector to the resistor assy...drop the resistor assy and see how the filter cover is then fastened to the box unit..

I see your filter cover is horizontal about 8 inches long 1 inch wide right next to the connector to the resistor assy...drop the resistor assy and see how the filter cover is then fastened to the box unit..

I dont have the brass screws that others have, mine is a sealed unit it looks like. I thought I read somewhere that the 03s didnt have a cabin filter? I took the blower out and reached up in there and cant feel a filter, or see the evap coil to see how it is.

I dont have the brass screws that others have, mine is a sealed unit it looks like. I thought I read somewhere that the 03s didnt have a cabin filter? I took the blower out and reached up in there and cant feel a filter, or see the evap coil to see how it is.


autozone and advanced auto have your filter listed. it is one larger piece where my 2000 is two pieces 1/2 ea sized smaller..

I can see your picture where the plastic is molded to recieve this filter. could be the screw is inthe round plastic shroud. then with the screw out pull down and toward the firewall /front end should unhinge.

autozone and advanced auto have your filter listed. it is one larger piece where my 2000 is two pieces 1/2 ea sized smaller..

I can see your picture where the plastic is molded to recieve this filter. could be the screw is inthe round plastic shroud. then with the screw out pull down and toward the firewall /front end should unhinge.

Yeah I agree it looks like a perfect slot for a filter. But there are no screws or anything, that piece doesnt even seem to have a slot that it could be removed. I had bought a cabin filter last year and went through this, not sure why the auto stores list them. Maybe we can do a survey of other 03 silverado owners and see if they have a filter....?

Yeah I agree it looks like a perfect slot for a filter. But there are no screws or anything, that piece doesnt even seem to have a slot that it could be removed. I had bought a cabin filter last year and went through this, not sure why the auto stores list them. Maybe we can do a survey of other 03 silverado owners and see if they have a filter....?


I found this, the 03 doesnt have one!
The following diagnosis might be helpful if the vehicle exhibits the
symptom(s) described in this PI.

Condition/Concern:
A customer may inquire about the availability of the passenger
compartment air filter (http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=air%20filter).

Recommendation/Instructions:
Starting in the 2003 model year, the passenger compartment air filter (http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=air%20filter) is
no longer available as a factory option. With the redesigned HVAC case,
there is no longer a cavity for the filter. The GM parts catalog
indicates there is a replacement filter available however there is no
provision for it.

Please follow this diagnostic or repair process thoroughly and complete
each step. If the condition exhibited is resolved without completing
every step, the remaining steps do not need to be performed.



GM bulletins are intended for use by professional technicians, NOT a
"do-it-yourselfer". They are written to inform these technicians of
conditions that may occur on some vehicles, or to provide information
that could assist in the proper service of a vehicle. Properly trained
technicians have the equipment, tools, safety instructions, and know-how
to do a job properly and safely. If a condition is described, DO NOT
assume that the bulletin applies to your vehicle, or that your vehicle
will have that condition. See your GM dealer for information on whether
your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


(c) Copyright General Motors Corporation. All Rights Reserved.

Thanks,
Mike Griffin
Fixed Operations Director

this is not good news.

the air filter was installed in many vehicles a time after the banning of R12 refrigerent. the reason this was needed these auto manufacturers found was that the coil spacing needed to get R134 to cool effectively was reduced into very small spacing..

THE FILTERS PROTECTED THESE EVAP COILS FROM GETTING PLUGGED WITH DEBRIS.

the other issue was foul odors emitting from the evap coil debris. you will find old TSB on that issue..

I would remove the resistor assy next to that molded slot . then look toward the driver side of the air duct you should see the evap coil input face.. see if it is coated with dust / other organic goo...

If it is dirty ,,you must figure out how you are going to clean up this..

this is not good news.

the air filter was installed in many vehicles a time after the banning of R12 refrigerent. the reason this was needed these auto manufacturers found was that the coil spacing needed to get R134 to cool effectively was reduced into very small spacing..

THE FILTERS PROTECTED THESE EVAP COILS FROM GETTING PLUGGED WITH DEBRIS.

the other issue was foul odors emitting from the evap coil debris. you will find old TSB on that issue..

I would remove the resistor assy next to that molded slot . then look toward the driver side of the air duct you should see the evap coil input face.. see if it is coated with dust / other organic goo...

If it is dirty ,,you must figure out how you are going to clean up this..


So I took out my condenser and cleaned the outside of it on both sides with a foaming coil cleaner and water. It definitely was dirty, not with actual particles, just with black dirt that washed off. I recharged the a/c and got better pressures. 41/253 on a 88 degree day. Today I even took the resistor out and was able to foam the evap coil and get a hose in there to rinse off. The evap coil didnt look bad.

After doing the condenser I road tested it and got down as low as 41.5 degree air out of the ducts! But my question is, after driving I went through a drive thru and the whole time my temp kept going up, by the time I left the temp had retreated to 58.7 degrees out of the ducts! Is that normal?
I still am having trouble with my compressor not always starting up and I have to wait a minute or so for it to engage. I changed the relay and still no change. What could that be???

So I took out my condenser and cleaned the outside of it on both sides with a foaming coil cleaner and water. It definitely was dirty, not with actual particles, just with black dirt that washed off. I recharged the a/c and got better pressures. 41/253 on a 88 degree day. Today I even took the resistor out and was able to foam the evap coil and get a hose in there to rinse off. The evap coil didnt look bad.

After doing the condenser I road tested it and got down as low as 41.5 degree air out of the ducts! But my question is, after driving I went through a drive thru and the whole time my temp kept going up, by the time I left the temp had retreated to 58.7 degrees out of the ducts! Is that normal?
I still am having trouble with my compressor not always starting up and I have to wait a minute or so for it to engage. I changed the relay and still no change. What could that be???

YOUR PROBLEM MAY BE LOW SIDE PRESURE COMING UP.
What is your low side pressure doing wen the vent tempt raises?

Your low side pressure controls vent tempt.

Ever One lb pressure rise on low side raises vent tempt 1 degree.

App. 32 low side gives 33-34 evaparator cooling and app 35-40 vent tempt if good circulation threw evaporator core.

Post back all of your low and high side readings.

So I took out my condenser and cleaned the outside of it on both sides with a foaming coil cleaner and water. It definitely was dirty, not with actual particles, just with black dirt that washed off. I recharged the a/c and got better pressures. 41/253 on a 88 degree day. Today I even took the resistor out and was able to foam the evap coil and get a hose in there to rinse off. The evap coil didnt look bad.

After doing the condenser I road tested it and got down as low as 41.5 degree air out of the ducts! But my question is, after driving I went through a drive thru and the whole time my temp kept going up, by the time I left the temp had retreated to 58.7 degrees out of the ducts! Is that normal?
I still am having trouble with my compressor not always starting up and I have to wait a minute or so for it to engage. I changed the relay and still no change. What could that be???

jump out the low pressure switch see if you still get that delay in the compressor clutch engagement.

pressures look better...still a little on the low side both hi/low.


like I stated before post what the pressures are with the doors open and the ac blower on max....with engine at the 1500-2000rpm ..


for your info.... with this r134 system as I stated before the coils are closer together this traps dirt more so than the r12 coils...also this close spacing causes water to interfere with the heat being tranfered to the refrigerent flowing thRew the evap...so on days with high dewpoints you will get poor cooling..not with the R12 SYSTEMS OF THE PAST...

YOUR PROBLEM MAY BE LOW SIDE PRESURE COMING UP.
What is your low side pressure doing wen the vent tempt raises?

Your low side pressure controls vent tempt.

Ever One lb pressure rise on low side raises vent tempt 1 degree.

App. 32 low side gives 33-34 evaparator cooling and app 35-40 vent tempt if good circulation threw evaporator core.

Post back all of your low and high side readings.

With my vent temps in the high 50's I get 48/246. I then drove and got the vents to 47 degrees and got 43/235.
As J Cat Asked, blower high, doors opened I get 45/240.

With my vent temps in the high 50's I get 48/246. I then drove and got the vents to 47 degrees and got 43/235.
As J Cat Asked, blower high, doors opened I get 45/240.

Low side readings are to high.
You Need to get low side pressure down.
Vent tempt drops when low side pressure drops.

To much oil and orfice tube not woring right and to much R-134a are a leading cause of low side high.

I pump out and replace orfice tube and recharge with set amount of R-134a.
And check and watch low side before adding the last 12 and last 6 oz. R-134a

Low side readings are to high.
You Need to get low side pressure down.
Vent tempt drops when low side pressure drops.

To much oil and orfice tube not woring right and to much R-134a are a leading cause of low side high.

I pump out and replace orfice tube and recharge with set amount of R-134a.
And check and watch low side before adding the last 12 and last 6 oz. R-134a

Ok I drained some refrigerant till my low side came down to the mid 30's, problem is my high is now just under 2000 at idle. My vent temp at idle though is high 40's which is better than before, but my vent temp goes up when I drive! This is so frustrating. Tomorrow I will completely recover the refrigerant, vacuum and refill 1.6lbs using my 30lb jug and scale, no mini can so I am sure 100% sure I put the right amount in.
We all agree 1.6lbs????

Low side readings are to high.
You Need to get low side pressure down.
Vent tempt drops when low side pressure drops.

To much oil and orfice tube not woring right and to much R-134a are a leading cause of low side high.

I pump out and replace orfice tube and recharge with set amount of R-134a.
And check and watch low side before adding the last 12 and last 6 oz. R-134a


Plus do I really need another orifice tube, I just changed it when I did the compressor and flush and stuff?

With my vent temps in the high 50's I get 48/246. I then drove and got the vents to 47 degrees and got 43/235.
As J Cat Asked, blower high, doors opened I get 45/240.

my opinion the low side looks fine at 45 psi with the as prior described test operation I asked...with the engine at the 1500-2000 rpm the high side should be around 300psi...240 psi is a little low..you need the higher pressure to get the evap to get very cold so it can absorb the heat passing thru..


my 2000 silverado takes 1.8lbs or about 30 oz of R134...

if this is what you require this maybe why you are a little low on the high side with the 240 psi...when adding you will see the high side to rapidly rise when getting at the full mark,,,this indicates you are at the correct amount...this is only a good indication when we get these 85-95 deg f air temps...

with these AIR temps ,, If it is around 300 psi you will not be over charged..

my opinion the low side looks fine at 45 psi with the as prior described test operation I asked...with the engine at the 1500-2000 rpm the high side should be around 300psi...240 psi is a little low..you need the higher pressure to get the evap to get very cold so it can absorb the heat passing thru..


my 2000 silverado takes 1.8lbs or about 30 oz of R134...

if this is what you require this maybe why you are a little low on the high side with the 240 psi...when adding you will see the high side to rapidly rise when getting at the full mark,,,this indicates you are at the correct amount...this is only a good indication when we get these 85-95 deg f air temps...

with these AIR temps ,, If it is around 300 psi you will not be over charged..

I can never get my high side over 250, no matter how much or little refrigerant I put in. Last year I did get 45/300 or so on a hot day. Why cant I get my high side pressure to go up? Could my new orifice tube be defective?

I can never get my high side over 250, no matter how much or little refrigerant I put in. Last year I did get 45/300 or so on a hot day. Why cant I get my high side pressure to go up? Could my new orifice tube be defective?


if it was 70 deg f air temp you will not get 300psi hi side...with the test proceedure I gave you with 90 deg f air temp your ac must go to 300 psi or it will not cool..

you better check on how much refrigerent to put in for your vehicle ..If your 6 OZ LOW this would explain the low high side pressure..


refrigerent is / has a temp pressure ratio...higher the temp the higher the pressure...this is with the ac running or OFF....

If you checked you pressure when it is 10 deg f air temp you would think you are very low on refrigerent...pressures will be low..

at 120 deg f you would be well over 300psi on the high side ..

I never had the chance to check this but I would guess 350 psi would be about right..

with the air temp at 85 deg f which is normal temp up in the northeast with dewpoints in the 60 deg f area the pressure should be 275 psi.. 90 deg f 300 psi...................

if it was 70 deg f air temp you will not get 300psi hi side...with the test proceedure I gave you with 90 deg f air temp your ac must go to 300 psi or it will not cool..

you better check on how much refrigerent to put in for your vehicle ..If your 6 OZ LOW this would explain the low high side pressure..


refrigerent is / has a temp pressure ratio...higher the temp the higher the pressure...this is with the ac running or OFF....

If you checked you pressure when it is 10 deg f air temp you would think you are very low on refrigerent...pressures will be low..

at 120 deg f you would be well over 300psi on the high side ..

I never had the chance to check this but I would guess 350 psi would be about right..

with the air temp at 85 deg f which is normal temp up in the northeast with dewpoints in the 60 deg f area the pressure should be 275 psi.. 90 deg f 300 psi...................

Yes I know, high air temp high high side pressure, thats why I didnt get why today in a parking lot with 95 degrees air I only got 245 on the high side and I definitely had more than enough refrigerant in my truck, I even tried letting some out and no luck.
Could a bad orifice tube cause low high side pressure?

Ok I drained some refrigerant till my low side came down to the mid 30's, problem is my high is now just under 2000 at idle. My vent temp at idle though is high 40's which is better than before, but my vent temp goes up when I drive! This is so frustrating. Tomorrow I will completely recover the refrigerant, vacuum and refill 1.6lbs using my 30lb jug and scale, no mini can so I am sure 100% sure I put the right amount in.
We all agree 1.6lbs????

I think J-cat posted his takes 1lb 8 oz.
My chart says 1 lb 9 -1/2 oz.
The correct amount for yours should be on your reciever dryer or under hood sticker.

If you recharge I would hold the charge a around 1 lb 5- oz and see what pressure does.

Then add up about 3 oz up to 1lb 8 0z and watch pressure.

And yes orfice tube controls pressure.
A bad one can throw off pressure.
If you do a recharge replace it.

At idle it is normaql for low side to raise from the 30 range up to the 40 range.
At 2K rpm with good air flow threw condenser it should come down to the low 30 range or on the road with good air flow threw condenser and rad.

The high side pressure is affected by air flow threw the condenser and also R-134a flow threw condenser and outside tempt and amount of charge in system.

If your vent tempt is raising on the road check for good air flow threw condenser and rad.
To much high side is going to raise low side and vent tempt.
Another thing you might check is the condenser tempt for hot and cold spots with a
LAZER NO TOUCH THERMOTER.
Also try to hook up gauges so you can watch while driving on road.

A/C Performance Table - 4.3L, 4.8L. 5.3L, 6.0, and 8.1L Engines:
- Ambient Air Temperature
-Relative Humidity
- Service Port Pressure
- Maximum Left Center Discharge Air Temperature

- Low Side
- High Side
These are the charts from the ambient temperature range you seem to be in:

25-29°C (76-85°F)
Below 35%
218-328 kPa (32-48 psi)
1240-1640 kPa (180-238 psi)
17°C (63°F)

35-60%
236-342 kPa (34-50 psi)
1290-1680 kPa (187-244 psi)
18°C (64°F)

Above 60%
250-365 kPa (36-53 psi)
1340-1760 kPa (194-255 psi)
20°C (68°F)

30-35°C (86-95°F)
Below 30%
266-386 kPa (39-56 psi)
1500-1940 kPa (218-282 psi)
21°C (70°F)

30-50%
280-397 kPa (41-58 psi)
1540-1990 kPa (224-289 psi)
22°C (72°F)

Above 50%
300-430 kPa (44-62 psi)
1600-2070 kPa (232-300 psi)
24°C (75°F)

This is GM's procedure: max cold setting, max blower, recirc on, driver window down 5-6 incches, vent mode, all vents open, idle in park 5 minutes.
Your pressures from your first post seem fine. Is your truck equipped with automatic or manual A/C? A bad recirc./air inlet actuator will prevent the vent temp from getting any lower if it is failed to the fresh air position. Have you had the HVAC control module scanned for any actuator DTC's?

Yes I know, high air temp high high side pressure, thats why I didnt get why today in a parking lot with 95 degrees air I only got 245 on the high side and I definitely had more than enough refrigerant in my truck, I even tried letting some out and no luck.
Could a bad orifice tube cause low high side pressure?

you already replaced the tube..

with the low, high side pressure , the lack of proper charge, dirty evap coils, or the compressor not pumping properly would cause this..

where did you get the 1.6LB refrigerent capacity for your vehicle ?


today if your in new york the temp will be 95deg f or more..add more refrigerent until the high side rises to 300 psi. see how much it takes ...just be sure to use the test proceedure I gave in the other posts.. It should not take too much more to achieve the 300 psi..

my vehicle the capacity is 30 oz. /1.8 LB... I WOULD NOT BE CONCERNED WITH THE AIR TEMP OF THE VENTS..THE PRESSURES ARE THE TELL ALL OF HOW IT IS CHARGED/OPERATING..

the temp door can cause a warmer air out the vents...debris interfering with the temp door...thats why the pressures are what you use to determine the ac performance...when that is settled then the venting temp issues like the door operation have to be delt with ..

you already replaced the tube..

with the low, high side pressure , the lack of proper charge, dirty evap coils, or the compressor not pumping properly would cause this..

where did you get the 1.6LB refrigerent capacity for your vehicle ?


today if your in new york the temp will be 95deg f or more..add more refrigerent until the high side rises to 300 psi. see how much it takes ...just be sure to use the test proceedure I gave in the other posts.. It should not take too much more to achieve the 300 psi..

my vehicle the capacity is 30 oz. /1.8 LB... I WOULD NOT BE CONCERNED WITH THE AIR TEMP OF THE VENTS..THE PRESSURES ARE THE TELL ALL OF HOW IT IS CHARGED/OPERATING..

the temp door can cause a warmer air out the vents...debris interfering with the temp door...thats why the pressures are what you use to determine the ac performance...when that is settled then the venting temp issues like the door operation have to be delt with ..

I changed the orifice tube and put an ac delco one in. Wound up having trouble getting the connection back in, threads seemed rough, had to buy a new line to fix it. It was worth it though, it comes with all new high low fittings, orifice tube already installed and ready to go. The orifice tube is a different style than my original, will post pics later. So Im vacuuming it now. When I went to the dealer they looked up my truck and said it takes 1.76lbs of r134a. I am using a scale and will put that amount in at most and then see what happens. Yeah with this heat I should easily get over 250, my truck is sitting in the sun on blacktop for the last 3 hrs so pressures should be high.
Will post back in a few how it went!

I changed the orifice tube and put an ac delco one in. Wound up having trouble getting the connection back in, threads seemed rough, had to buy a new line to fix it. It was worth it though, it comes with all new high low fittings, orifice tube already installed and ready to go. The orifice tube is a different style than my original, will post pics later. So Im vacuuming it now. When I went to the dealer they looked up my truck and said it takes 1.76lbs of r134a. I am using a scale and will put that amount in at most and then see what happens. Yeah with this heat I should easily get over 250, my truck is sitting in the sun on blacktop for the last 3 hrs so pressures should be high.
Will post back in a few how it went!

Ok good news to report.... my vent temps when driving dropped to 41.3 degrees and then when parked/idling it only went up to 49.5, it was 92 degrees out! I refilled it with slightly over 1.8lbs as I didnt shut the valve quick enough as it was sucking it in pretty quick. I took pics of my gauges before I drove it but after it was refilled. Do these numbers look decent? I didnt put gauges on it after I drove it, honestly it seems to work good so I didnt want to touch the lines.
So was it the new style orifice tube, the new one has white salt like crystals as a metering device versus the old style of a screen.
Water was pouring out the evap drain, really ringing out the humidity. I am driving 25 miles tonight so that will be my full test. I never realized that just having one can too much in could hurt efficiency as much as it did. Thanks everyone for getting me to add the right amount of refrigerant.

Ok good news to report.... my vent temps when driving dropped to 41.3 degrees and then when parked/idling it only went up to 49.5, it was 92 degrees out! I refilled it with slightly over 1.8lbs as I didnt shut the valve quick enough as it was sucking it in pretty quick. I took pics of my gauges before I drove it but after it was refilled. Do these numbers look decent? I didnt put gauges on it after I drove it, honestly it seems to work good so I didnt want to touch the lines.
So was it the new style orifice tube, the new one has white salt like crystals as a metering device versus the old style of a screen.
Water was pouring out the evap drain, really ringing out the humidity. I am driving 25 miles tonight so that will be my full test. I never realized that just having one can too much in could hurt efficiency as much as it did. Thanks everyone for getting me to add the right amount of refrigerant.

Couldnt get pic to post, anyways my pressures were 48/252.

Ok good news to report.... my vent temps when driving dropped to 41.3 degrees and then when parked/idling it only went up to 49.5, it was 92 degrees out! I refilled it with slightly over 1.8lbs as I didnt shut the valve quick enough as it was sucking it in pretty quick. I took pics of my gauges before I drove it but after it was refilled. Do these numbers look decent? I didnt put gauges on it after I drove it, honestly it seems to work good so I didnt want to touch the lines.
So was it the new style orifice tube, the new one has white salt like crystals as a metering device versus the old style of a screen.
Water was pouring out the evap drain, really ringing out the humidity. I am driving 25 miles tonight so that will be my full test. I never realized that just having one can too much in could hurt efficiency as much as it did. Thanks everyone for getting me to add the right amount of refrigerant.

adding refrigerent as I stated before the high side pressure should be monitored..I understand it is working good now so you don't want to mess with it but just to be sure you did not add too much refrigerent..

the last few ounces does make a difference when it is 90 plus out to get the max cooling.

when the system rapidly sucks in the refrigerent I know the compressor is pumping good..

with the issues you had most times it would be a slightly low charge and/or the evap filter or evap is dirty... then the temp doors sticking ..

these spec's are far to wide in range...with the other manufacturers the numbers have not too much variation..some of these readings would not be good if you want a good amount of cooling..

these spec's are far to wide in range...with the other manufacturers the numbers have not too much variation..some of these readings would not be good if you want a good amount of cooling..

What I will do is hook up the gauges after I drive the 25 miles tonight and see what I get when its cooling real good and the refrigerant is pumped up. Hopefully those numbers will make sense!

What I will do is hook up the gauges after I drive the 25 miles tonight and see what I get when its cooling real good and the refrigerant is pumped up. Hopefully those numbers will make sense!

When you hook up gages check at idle and then check at 2K RPM and if truck is very warm put a window fan in front of rad to get good air flow threw condenser.
Good luck And let us know how it goes.

I am wondering if the new expanson tube helped it?

Couldnt get pic to post, anyways my pressures were 48/252.

Is that at idle or speeded up?
LOW SIDE IS USUALLY LOWER AT 2K RPM.
Should drop down in the 30 range.

Is that at idle or speeded up?
LOW SIDE IS USUALLY LOWER AT 2K RPM.
Should drop down in the 30 range.


Ok so after driving for 30mins I tested things, I was getting 42.5 out of the vents with 96 degrees outside! My pressures at idle were 42/250.....at 2500 it went to 32/298-305.... have a range because was looking through my hood to see the gauges, kinda hard! Either way this was the best reading Ive ever seen on my truck since doing all this work.
I wonder if that newer style orifice tube helped, but also thing putting the right amount of refrigerant was key! I think low 40's on a 90+ deg day is pretty good!
Pressures look good, and make sense?

Ok so after driving for 30mins I tested things, I was getting 42.5 out of the vents with 96 degrees outside! My pressures at idle were 42/250.....at 2500 it went to 32/298-305.... have a range because was looking through my hood to see the gauges, kinda hard! Either way this was the best reading Ive ever seen on my truck since doing all this work.
I wonder if that newer style orifice tube helped, but also thing putting the right amount of refrigerant was key! I think low 40's on a 90+ deg day is pretty good!
Pressures look good, and make sense?

10-4 on right amount.
Pressure and tempt looks good now.
Good Luck.
PS.
One other thing that has a big affect on cooling is humidity.
Real high humidity cuts cooling way down.

10-4 on right amount.
Pressure and tempt looks good now.
Good Luck.
PS.
One other thing that has a big affect on cooling is humidity.
Real high humidity cuts cooling way down.


My truck showed 97 degrees on a 3 lane highway, stop and go traffic, I held 44-46 out of the vents! Thats impressive if you ask me. Should I ever expect to see high 30's out of the vents on a cooler day, or is that pushing it? lol

My truck showed 97 degrees on a 3 lane highway, stop and go traffic, I held 44-46 out of the vents! Thats impressive if you ask me. Should I ever expect to see high 30's out of the vents on a cooler day, or is that pushing it? lol

Yes and no.:lol2:

Not in stop and go on a hot day and high humidity.
But on the road truck moving 45+ mph and outside temp under 90 and lower humidity yes you can get upper 30 out of vents.

I just recharged a for Taurus that has beenn sittibng several years and AC R-134a leaked off.

Pumped down and added oil and dye and correct charge of R-134a.
At idle low side 40 and 200 high.
At 2K rpm low 30 and high 250.
Hot and humid here.
Got iside and rolled up windows and put AC on max and speeded up engine to 2K.
Stuck regular thermometer in vent.
Beleve it or not vent out put upper 20.
Went and got laser infrared thermometer.
Shot laser inside vent and see 17 on digital scale.

That is the coldest one I have ever say.
Think I will hook gages back up and see what they are doing.

Usually on the road with low side at 30 you can get upper 30 from vents.

Good luck on yours and let us know how it goes

Yes and no.:lol2:

Not in stop and go on a hot day and high humidity.
But on the road truck moving 45+ mph and outside temp under 90 and lower humidity yes you can get upper 30 out of vents.

I just recharged a for Taurus that has beenn sittibng several years and AC R-134a leaked off.

Pumped down and added oil and dye and correct charge of R-134a.
At idle low side 40 and 200 high.
At 2K rpm low 30 and high 250.
Hot and humid here.
Got iside and rolled up windows and put AC on max and speeded up engine to 2K.
Stuck regular thermometer in vent.
Beleve it or not vent out put upper 20.
Went and got laser infrared thermometer.
Shot laser inside vent and see 17 on digital scale.

That is the coldest one I have ever say.
Think I will hook gages back up and see what they are doing.

Usually on the road with low side at 30 you can get upper 30 from vents.

Good luck on yours and let us know how it goes

Now you ruined my day, I cant let a Ford have colder air than me! lol With it that cold are there concerns for freezing the coil? What would make that car so much colder than others, I would think our trucks with bigger coils would be more efficient and colder.
So far everything is fine on mine, I wont be touching it. Yesterday my girl had to shut her vents in my truck because she was too cold, and shes never done that!

Now you ruined my day, I cant let a Ford have colder air than me! lol With it that cold are there concerns for freezing the coil? What would make that car so much colder than others, I would think our trucks with bigger coils would be more efficient and colder.
So far everything is fine on mine, I wont be touching it. Yesterday my girl had to shut her vents in my truck because she was too cold, and shes never done that!

getting 40-45 deg f out of the vents is normal on a hot day.. anything below this would not be normal. sounds like 30 is in deg C not F.


common sense .................lets say the vents did somehow get to any temp below 32 deg f...guess what would occur ??????????????

the evap would turn into a solid block of ICE !