AC Issues

[bennuss]

I recently put in a new compressor and accumulator. I didn't change the orifice tube since it is almost impossible to get to. I added freon and oil with dye and it would work fine sporadically sometimes it wouldn't get cold at all other times it would be freezing. This lasted about a week. I noticed that when it was hot the clutch was engaging fully but i felt the pipe near the firewall and it wasn't cold as if the compressor wasn't compressing and then it would start compressing and it would get cold. The compressor sounds different when it was making the car cold. This led me to rule out a problem in the air control doors. Now there seems to be a leak which is bad since it runs out almost immediately. The problem is finding it since there isnt any oil residue or freon dye where i can see. Any ideas?

(Anyone know some shortcuts where i dont have to remove the vacuum brake brake booster to change the orifice tube?)

[Tech II]

What year?

[bennuss]

2005 buick century
This thing is driving me crazy. i had to change the compressor because clutch was shot. i filled the system with the 9oz of oil and the the 2.2 lb of r134a. it was freezing cold but that didnt last . it was hot for a while then a few days later it was freezing cold. the doors seem to be working since heat gets blended in properly. any ideas?
I saw somewhere that i dont have to remove the brake lines just unscrewing the brake booster should give enough clearance to change the orifice tube.
are the two sides - the nuts to open a 23mm and a 20mm ?

Is it possible that sometimes the compressor compresses and sometimes not even though the clutch is engaged? It sounds louder when it is compressing and i am getting some cold air (it is low now)

[rkvons]

Originally Posted by bennuss

2005 buick century
This thing is driving me crazy. i had to change the compressor because clutch was shot. i filled the system with the 9oz of oil and the the 2.2 lb of r134a. it was freezing cold but that didnt last . it was hot for a while then a few days later it was freezing cold. the doors seem to be working since heat gets blended in properly. any ideas?
I saw somewhere that i dont have to remove the brake lines just unscrewing the brake booster should give enough clearance to change the orifice tube.
are the two sides - the nuts to open a 23mm and a 20mm ?

Is it possible that sometimes the compressor compresses and sometimes not even though the clutch is engaged? It sounds louder when it is compressing and i am getting some cold air (it is low now)

When you are going to recharge it, change out both the high and low side service ports. These leak when they get old. Make sure you coat the oring on the high side and coat the low side Schrader valve with a little PAG oil.

[DeltaP]

Put manifold guages on it, check pressures. If none or very low you've got a leak. If pressure is sufficient, run system and check pressures. If low side drops into a vacuum and/or the high side goes off the dial and the compressor shuts down then you have a restriction. Probably that O tube is restricted with debris or icing up from moisture. Replace the O tube and a complete evacuation and pump down is needed.
After pumping down for at least 1/2 hour, shut valves,turn off pump and see that it holds vacuum for 15 minutes. Reading should be around 29 in/hg. on your guages. If its not holding then you've got other leaks.
To leak test a partial charge must be in the system. Dye testing is best done in low light with the use of an ultraviolet lamp. The cheap lamps dont work very well. Or you can start with a bubble test of thick soapy water,(a lot of dish liquid soap mixed with water in a spray bottle), sprayed heavily on each component,hose and fitting. Check carefully,one section at a time for growing bubbles. Can be followed up by an electronic leak detector on a dry engine, indoors,(run engine to dry). The evaporator is best checked with the electronic detector in the dash vents. Put the tip in the louver and turn the fan on and off briefly, hold the tip there to see if detects anything. Do it several times. Also clear out the evap drain tube of trash and crap with a short wire,( any green residue might be dye indicating an evap leak), then put the detector tip up there to detect any leak. Don't get the tip wet. God help ya if the evap is bad. That's a big job, entire dash comes out. But it's do-able even in your driveway and can save ya $1K. Make repairs, pump down again to see if it holds vacuum. If it's OK replace the drier and again pump down throughly. Recharge with proper amount of refrigerant and any lost oil.
Sorry this turned into a tutorial but certain things can't be assumed and all leak test methods have their limitations.

[bennuss]

I checked the ports for leaks they seem solid.

After I changed the compressor I did a vacuum test for 24 hours and it held.
The compressor never shuts down at least the clutch remains engaged just sometimes i get cold air from the passenger side (because it is low now but not refilling fully till i figure out the problem) and sometimes nothing yet the pressure remain with range. the high side doesnt get crazy high which would indicate a restriction. i did a dye test under the hood nothing.
Will check the evaporator
The drier is new; replaced with compressor.
How do i clear out the evap drain tube?
Any secret to make it easy to get to the orifice tube without disassembling the brake booster. Any tool that would be able to get in and loosen the nut?

[DeltaP]

Any secret to make it easy to get to the orifice tube without disassembling the brake booster. Any tool that would be able to get in and loosen the nut?
__________________________________________________ ______________
The booster needn't come out but the ABS unit brackets will need to be unbolted and the unit lifted up. Do not remove it just lift it for access. 3 bolts through wheel well and one from above. If I remember its easier to remove the whole line from drier and evaporator so you can get the tube out of the line.
Just remember dye isn't a replacement for oil. Sometimes too much dye is added and that'll gum up an O tube. Are you weighing in the refrigerant or guessing.

[bennuss]

I put in proper amount of oil. Ue the pag 46 with the dye in it. i weighed the fren and put in the proper amount of 2.2lb.
So i should disconnect the hose where it connects to the evaporator under the low pressure port and where it connects to the drier Correct?

[DeltaP]

Ok on that. Remove the line from the car so ya dont damage,kink it. The O tube is a be-otch to remove from the line when its still in the car. Flush the line after ya get the tube out.

[bennuss]

Need to disconnect the battery and pull the airbag relay since I am working under try be dash?

[Tech II]

No you did not put the right amount of oil in, if you added 9 oz., and that's probably why the system is making noise and varying the cooling......

When you get a new compressor, sometimes they come wet(meaning they have oil in them), or they come dry.....If wet, you are suppose to empty them completely.....

Now, you were suppose to take your old compressor, remove the the drain bolt from the side and drain it into a measuring cup.......If you drained LESS THAN 2 oz., you put 2 oz. into the new compressor....if you drained more than 2 oz from the old compressor, whatever you drained out, you add the same amount to the new compressor(if you drained 3 oz., you add 3 oz)....the whole system holds about 8 oz(this will be stored throughout the system in low points) like the accumulator, the condenser, the evaporator and compressor, etc......so if you added 9 oz of pag, you have overfilled the system with oil, which will inhibit cooling....you should have added the proper amount to the compressor as I outlined, and you should ave added 2-3 oz to the new accumulator......the excess oil can reduce heat exchange in the evap and condenser, and also cause a chugging sound in the compressor....

If you have a leak, and there was none before, then the leak has to be where you opened up the system....the compressor and the accumulator.....if the black light does not show the dye, then try a soap test at those joints.....

[bennuss]

I didnt put 9oz into the compressor. My old compressor had absolutely no oil in it just a lot of metal shavings. i put about 4oz into it and another 4oz into the new accumulator. used up a 8oz bottle.

[Tech II]

"i filled the system with the 9oz of oil and the the 2.2 lb of r134a."

I didn't write this......

You should have put 2oz in the compressor, and 2-3 in the accumulator...so you you put an "extra" 3oz in....

This is what I have been taught:

HVAC systems circulate refrigerant oil with refrigerant through the system, and when a system is recovered, some of the oil remains in other system components as a film. This is why you must pay close attention to the amount of oil in a compressor upon removal.

HVAC systems with too much oil can result in reduced cooling capacity, and systems with excessive lubricant will create an internal coating that results in less heat transfer. So, if you don’t know how much oil was drained from the compressor, then you won’t know how much remains in the system, and then you will not know how much to add back. Also, keep in mind that many new compressors come pre-filled with oil, so you’ll have to drain the appropriate amount from that compressor before installing.

[DeltaP]

"My old compressor had absolutely no oil in it just a lot of metal shavings".
Well there ya go. Ya need to start all over again and flush each component.

[bennuss]

I am getting condensation- ice like on the tube past the orifice tube. and i get cold on the inside and then it goes away and no cold on the inside . but the pressure always remains at 17 on the low and 150 on the high. this is after a couple of days after i put in freon. When i put it in it was working fine then goes back to this everytime and never goes lower.