Okay, Am I crazy? Or just Blind?

[HanibalTheCannibal]

I cannot find these two things on my 2001 Silverado ext cab 5.3:

1. Low pressure AC fitting to charge freon.

2. PC valve.

(1) I have looked all over the accumulator for the fitting, along the hose etc and I dont see it. I am a certified EPA 609 AC Tech (just as a hobby for side money) but I am stumped as to where the heck this thing is. I hope I do not have to use a pierce valve. They always leak.

(2) I looked under the vortech cover for the pc valve, and cannot see it

[kenwood guy]

[quote=HanibalTheCannibal]I cannot find these two things on my 2001 Silverado ext cab 5.3:

1. Low pressure AC fitting to charge freon.

2. PC valve.

(1) I have looked all over the accumulator for the fitting, along the hose etc and I dont see it. I am a certified EPA 609 AC Tech (just as a hobby for side money) but I am stumped as to where the heck this thing is. I hope I do not have to use a pierce valve. They always leak.

(2) I looked under the vortech cover for the pc valve, and cannot see it


did you look at the suction side of the compressor for a fitting or maybe there are caps you have to remove first at the lowside accumulator

[Ape0r]

IIRC the PCV valve is on the d/s valve cover close to the firewall. I'm wiring some stuff later, and I'll have a look and post back what I find.

[HanibalTheCannibal]

The only caps (2) are on the high side (smaller hose). I understand that you never charge on the high pressure side of an AC system. I have verified these are HIGH pressure because I put a gauge on them PFFT!! 120 pounds+ And besides the charging hose/can tap I have is a different size then these two fittings. I am positive there are no l ow side fittings. I just cant understand why
Ugh

[kenwood guy]

Originally Posted by HanibalTheCannibal

The only caps (2) are on the high side (smaller hose). I understand that you never charge on the high pressure side of an AC system. I have verified these are HIGH pressure because I put a gauge on them PFFT!! 120 pounds+ And besides the charging hose/can tap I have is a different size then these two fittings. I am positive there are no l ow side fittings. I just cant understand why
Ugh

according to my chilton manual the low side charging port is near the accumulator the cap should be marked with the letter "L" on the picture its right on top my guess is if its not there then it had to been replaced at one time if you need to charge it why not go through the high side but only when the pressure is equalized on both sides or off for while and one more thing the low side lines might insulated with that black rap foam did you remove that and check???

[HanibalTheCannibal]

This truck had 38K miles on it. I kind of doubt it has been replaced. I have a clear carfax report, and mechanical history was found in glove box. Plus the woman had the dealer service the truck, so they were able to tell me what maintenance schedule I should follow, and what has/has not been done to the truck.

There is definitely not one on top of the accumulator, I have not unwrapped any hoses. There is no wrap on the hoses except at the radiator. ANd I would definitely be able to see a fitting I am sure.


I am going to look over it again right now.

BRB

[kenwood guy]

good luck i would not dare go outside in this heat

[MT-2500]

Originally Posted by HanibalTheCannibal

I cannot find these two things on my 2001 Silverado ext cab 5.3:

1. Low pressure AC fitting to charge freon.

2. PC valve.

(1) I have looked all over the accumulator for the fitting, along the hose etc and I dont see it. I am a certified EPA 609 AC Tech (just as a hobby for side money) but I am stumped as to where the heck this thing is. I hope I do not have to use a pierce valve. They always leak.

(2) I looked under the vortech cover for the pc valve, and cannot see it

Kinda strange it having 2 high side fittings. Are they both the same sise?
On a hot engine you may find up to 120 lbs or more on low side without comp running.
Follow the low side hose/line from the compresser back to the eveperator and dryer. If it has one should be there someplace. Someone could have replace the line or hose with one that did not have a fitting on it.
Does the dryer have a pressure switch on it or a extra schrader valve?
If so you can remove switch and tap in there. But if 3 wire switch do not jump it to run compresser.
Last but not least you could pump down system and shot a fixed charge threw the high side fitting with compresser and engine not running.
Also here is a good AC link.
http://www.autoacforum.com/
Good luck and let us know how it goes.
MT

[HanibalTheCannibal]

Originally Posted by kenwood guy

good luck

Well, I have confirmed there is NO low pressure fitting. My options are to exchange the accumulator, which means a flush/vaccum/recharge. Or I can get a Pierce valve. I really dont like those things, they lose some freon but maybe they are made better then ones I have used on R22 systems.

I found the PCValve. I pulled the old one, and you know what is weird? It is absolutely hollow. There is no rattley thing in there. No signs of mods, just an empty PCValve fitting. It is exact same shape as the one I put in, but nothing inside ofit. The one I have bought has the rattley thing inside. The one I removed said ACDelco on it, the one I put in is a Deutsch (?) or whatever.

Whats up with that? Any thoughts?

EDIT** Here is a quote from the autoAC forum, the topic was a 2001 silverado AC:

" I believe the two ports are on the low side, the larger hose is the high side I think, but I could not find a port on it. "

So is the smaller hose the LOW side? I always knew the small hose to be the HIGH side. Can anyone confirm?

[HanibalTheCannibal]

OK Figured it out. Those two fittings are on opposite ends of the orifice tube. One is the high side, one is the low side. How nice of them to put the orifice tube nice and accesible My gauge readings are normal considering the ambient temp (93F).

*whew*

But whats up with the hollow PCValve?

[MT-2500]

Originally Posted by HanibalTheCannibal

OK Figured it out. Those two fittings are on opposite ends of the orifice tube. One is the high side, one is the low side. How nice of them to put the orifice tube nice and accesible My gauge readings are normal considering the ambient temp (93F).

*whew*

But whats up with the hollow PCValve?

Glad you got it figured out.
I had forget about that orfice tube deal.
MT

[silverado122775]

haha .. you said Orfice. LOL

[guumbah]

Originally Posted by HanibalTheCannibal

I found the PCValve. I pulled the old one, and you know what is weird? It is absolutely hollow. There is no rattley thing in there. No signs of mods, just an empty PCValve fitting. It is exact same shape as the one I put in, but nothing inside ofit. The one I have bought has the rattley thing inside. The one I removed said ACDelco on it, the one I put in is a Deutsch (?) or whatever.

Whats up with that? Any thoughts?

Mine was like that too. Chevy replaced the normal "rattly" PCV valves on some of these with a fixed orifice type due to oil contamination fouling the TB. There was a TSB, I think. I read all this in some other forums. If I can find the link, I'll post it. Supposedly, if you have the fixed orifice type, you should replace it with one. I have never been able to find one aftermarket, though, so I think you'd have to go to a dealership. I changed mine (before I knew about this) with the normal type from the auto parts store, and have not had the contamination problem. It has not been very long, but supposedly you see deposits on the TB right away. I'm just going to keep my eye on it.

[guumbah]

Here's the TSB. Doesn't mention the TB deposits, but the forum I remember reading said that was a sign of the problem in addition to oil consumption (which I don't have either).



Higher Than Expected Engine Oil Consumption (Replace PCV Valve) #01-06-01-029
Higher than Expected Engine Oil Consumption (Replace PCV Valve)
1999-2002 Chevrolet and GMC C/K Models

2002 Cadillac Escalade

with 5.3L or 6.0L Engine (VINs T, N, U - RPOs LM7, LQ9, LQ4)

Condition
Some customers may comment on higher than expected engine oil consumption. They may further comment on consumption in the range of 2,000 miles (3,200 km) or less per quart (0.946 liter) of oil under normal driving conditions.

Cause
The condition may be due to the PCV Valve flow rate under certain engine operating conditions.

Correction
Verify that the oil consumption is not the result of an oil leak or other engine concern.
Dealer should perform an oil consumption test. The vehicle should have accumulated over 4,000 miles (6,450 km) before establishing the oil consumption rate. Reference Service Bulletin #01-06-01-011, Information on Engine Oil Consumption Guideline, for details.
Remove the PCV Valve and inspect the hose going to the intake manifold for signs of excessive oil being present.
If excessive oil is present in the PCV hose, replace the PCV Valve Type 948C (2) with a new-style fixed orifice PCV Valve Type CV2001-C (1). See Fig. 1 - PCV Valve Identification.
FIGURE Figure 1 -- PCV Valve Identification(c)




(1) New style fixed orifice PCV Valve Type CV2001-C
(2) Spring and plunger style PCV Valve Type 948-C


Important
Do not install the new style fixed orifice PCV Valve on vehicles equipped with the 4.8L V8 Engine (RPO LR4). Use of this orifice on the 4.8L V8 engine may affect engine idle quality and engine RPM control.



Important
The new style fixed orifice PCV Valve contains no moving parts, and does not rattle when shaken.


If the vehicle has an orifice style PCV Valve, investigate other causes for high oil consumption.

Parts Information
Part Number
Description
Qty

12572717
Valve, PCV Type CV2001-C
1


Parts are currently available from GMSPO.

[HanibalTheCannibal]

hmmm..... Ok. The thing is the truck runs SOOOOO much better now. Should I just keep an eye on it? Do I check it by removing the PCValve and look for oil, or what? There is no chance of this hollow one going bad since there really isnt any parts inside, it s just a fitting. I hope I can still find the old one in the trash, it was clean, and er, eh.... Hollow .

Good info, I appreciate this.

Should I keep the new one from parts store, or put the hollow one back in?