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1994 Chevy Suburban Rear air Expansion valve

pmontgomery on Wed October 24, 2007 9:04 PM User is offline

Year: 1994
Make: Chevy
Model: Suburban

I just got sent a new rear Expansion valve for my suburban. The original in the suburban has the pigtail end with the clip that clips it to the
tube coming off the evaporator. The new one I just got sent is a little longer and does not have the pig tail end. I ordered it from Arizona Mobile Air.
Aren't these expansion valves for the suburban's without the pigtail end, prone to causing a freon flood back to the compressor in some cases?
I'm not sure it will even fit since it is a little longer. I think I may return it and get one local like the one that came off the suburban.
Comments?

pmontgomery on Wed October 24, 2007 9:22 PM User is offline

Found this on Alldata...

CAUSE

When the rear A/C system is shut off, a refrigerant flood back condition may occur through the rear A/C system. This flooding degreases the internal parts of the compressor resulting in rapid slider block wear and the resulting loud knocking noise. A poor contact between the TXV capillary tube and the rear evaporator outlet tube can allow the TXV to remain open when the rear system is not in use. The open TXV may allow liquid refrigerant to flood back through the rear system (liquid line, TXV, evaporator, rear suction line) and subsequently flood the compressor.

TRB on Wed October 24, 2007 10:10 PM User is offlineView users profile

If this is the valve you received there should be no issues with the capillary tube. Use a hose clamp to attach it to the suction line and wrap it with the black tar like tape.



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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
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pmontgomery on Wed October 24, 2007 10:13 PM User is offline

That is not the one I recieved. This one is. Part number 31-10988

Pat,
Here is what I found, if this is the correct one you can order it off the web site.

http://www.ackits.com/merchant.mvc?Screen=PROD&Store_Code=01&Product_Code=31-10988&Category_Code=


Thank you,
David Chatfield

Online Store
Auto A/C Information Forum


Edited: Wed October 24, 2007 at 10:13 PM by pmontgomery

TRB on Wed October 24, 2007 10:22 PM User is offlineView users profile

ACDelco is running like crap at this moment. Give me a few and I post back what I find.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

TRB on Wed October 24, 2007 10:28 PM User is offlineView users profile

So I'm not just spinning my wheels here, which engine is in this vehicle?

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

pmontgomery on Wed October 24, 2007 10:51 PM User is offline

350

TRB on Wed October 24, 2007 10:56 PM User is offlineView users profile

That what I thought. Delco lists a 15-50445 but I can not cross it with the data I have at home. No image for this on the Delco site either to compare with. I would be glad to research this a little in the morning or you can return it if you like. Just let me know and I'll work with you either way.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

GM Tech on Thu October 25, 2007 8:25 AM User is offline

The biggest problem back in '94 was that the capillary tube was attached to the suction pipe by ONLY the last half inch - this is the "dead zone" of the capillary- between the crimp and the soldered end- used for processing of the valve only-- With a see-through suction hose installed at the compressor- I could see liquid entering the compressor with rear a/c OFF-- When I attached 3-5 inches of the capillary to the suction pipe (and insulated it with tar tape) the liquid flow immediately stopped and compressors lived....this was the basis of the TSB that came out in late '94..........when those compressors knocked- you could hear them 200 ft away!! Liquid refrigerant casued extreme wear to the aluminum slider blocks- you could easily identify those worn- (off the vehicle) by the amount of rotational lash they exibited....

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

pmontgomery on Thu October 25, 2007 9:16 AM User is offline

Suffice to say they can be used as long as you get the capillary tube attached properly.
Mine did have one like that originally 4 years ago when the compressor went.
I changed it to the new style because of this when I rebuilt the system.
Maybe that's what killed my compressor back then!

Cussboy on Thu October 25, 2007 3:51 PM User is offline

My '94 Sub (167K miles) has never needed the rear AC worked on, but it is on its 3rd compressor. I had compressor (new, not rebuilt, R4), accumulator, and orifice tube replaced twice since I bought it in 2000. Orifice tube was free of debris in both cases; first time was a slight knocking sound plus a leak in the compressor body, and second time was a leak in the compressor body. I'm in Arizona, so AC is on practically all the time; a local radio mechanic says to always have the rear fan ON medium or high whenever the front AC is engaged, to avoid liquid refrigerant getting into the compressor. That seems to make sense to me: if it can't exchange enough heat to vaporize, then it returns to compressor as a liquid, not good.

GM Tech on Fri October 26, 2007 12:12 AM User is offline

Yeah that works- running the rear a/c all the time-- But we tried it in Houston at night--the backs of our ears froze--even with rear on low-- and it can't be on if any women are in the truck!! They'll beat you to death with "turn it off" mentality because they are too cold--- probably would be okay on a rear heat and rear air unit-- just adjust the temperature-- the one I tested was a rear air only unit.........

-------------------------
The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

ice-n-tropics on Fri October 26, 2007 5:21 PM User is offline

GM Tech,
Did some road trip Burb testing through Houston with GM/LT back starting in 87 and later. Were you there?
Old IV guy

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Isentropic Efficiency=Ratio of Theoretical Compression Energy/Actual Energy.
AMAZON.com: How To Air Condition Your Hot Rod

Cussboy on Fri October 26, 2007 5:56 PM User is offline

Hey, GM Tech - that's a Diversity Violation for stating that the women are always cold. However, it's true.

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