Alfa Romeo Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
273 Posts
Discussion Starter #1
My '91 that had been running for three years on ES12a stopped cooling this summer. I checked the charge and the high side doesn't get past 100 PSI no matter if I rev the engine or even add some extra charge to the low side. When it was originally charged, the high side was getting to 220 PSI and the low side was about 40PSI (on a similar 85 degree day). I checked the dryer and the valve and the flow through is just fine (not that these could cause lack of high pressure!)
Can anyone enlighten me as to whether this is a known compressor failure mode? It has ~100K miles on it. If they do fail this way, should I attempt a repair or replace it/ Anyone with a used compressor?

Thanks, Alfahill
 

·
Registered
Joined
·
503 Posts
Don't rebuild, buy a new compressor for about $250 from by boy Ricky Coleman at:

AC Parts Warehouse: 972-772-5502
Ricky Coleman
[email protected]
2012 Industrial Blvd.
Rockwall, TX 75087
(164 Sanden compressors and rebuilds)

He takes your old pulley (which is the hard part to get as it is discontinued), resurfaces it, and installs it on a new Sanden compressor.

There is no better deal out there.
 

·
Registered
Joined
·
273 Posts
Discussion Starter #3
Jason, Thanks for the information. I have an extra pulley and clutch that I could install, but before buying a new SD709, I wanted to see if anything other than the compressor could be behind the low pressure on the high side. It seems that all the information here points to shaft seal failures, but that is not my problem. I am not loosing charge, just failing to go over 100 PSI on the high side. I can charge the low side up to 50 PSI and the high side keeps going up, but it won't get past 100 PSI even if I go higher on the low side
If anyone has come across an internal failure that can cause these compressors not to compress, I would feel better about ordering a new compressor.
 

·
Registered
Joined
·
503 Posts
You could have a bad expansion valve (blown open).

I would reduce your low-side pressures. 50 PSI is too high. Sounds like the system is overcharged. If hi side doesn't get resolved by this, than compressor may be shot.
 

·
Registered
Joined
·
1,233 Posts
I would reduce your low-side pressures. 50 PSI is too high. Sounds like the system is overcharged. If hi side doesn't get resolved by this, than compressor may be shot.
I agree. 50 PSI for low-side pressure using this alternative refrigerant (mostly propane I heard) is somewhat high. If the high side does not go up then the compressor might not be doing its job.

I gather you have checked that the A/C compressor clutch was engaged during the test.
 

·
Registered
Joined
·
273 Posts
Discussion Starter #6
Yes, ES12a is a blend of propane and isobutane if I remember correctly. It worked great for 3 years. 50PSI was just an attempt today to see if I could boost the high side pressure, but it did not help. The compressor had been running at 30-40PSI on the low side when it was cooling fine and the high side used to go over 200 psi. The clutch does engage at about 20 PSI and the high side does go up, but it doesn't go past 100 psi. Most likely cause is that the compressor is no longer able to compress. Probably wise to change it after 100K miles. Alfahill
 

·
Registered
Joined
·
2,639 Posts
Not to be weird but I'm thinking that explosive gasses in the engine bay are really not a good idea. If you have a leak and some of it gets to the alternator brushes or near the dist cap you will be in a whole world of hurt!

JMHO

Paul
 

·
Registered
Joined
·
273 Posts
Discussion Starter #8
The hydrocarbon dangers have been discussed a lot and I am well aware. I don't want to start that discussion again here, so this is the last post on the subject from me. I feel that there are some level of danger in everything we do, and the gallons of gasoline in the car are far more dangers from my prespective. The right mix of air and HC to burn this stuff isn;t easy to get. I have a heck of time sometimes getting a propane torch to catch with my spark maker!
 

·
Premium Member
Joined
·
27,300 Posts
My money is on a problem with expansion valve metering or PDI valve where you service system.
 

·
Registered
Joined
·
273 Posts
Discussion Starter #10
Steve, I noticed that the condensor does get hot, but the area around the expansion valve does not get cold. Is the PDI valve also called the EDR valve and used to bleed excess high side pressure into the compressor intake line? If so, that valve sticking open could prevent high side pressure build up. Perhaps it is wise to try to check these since I have spares on hand. Do you know if the PDI valve is located in the expansion valve or in that cylinder that is mounted on the right side of the engine bay? Thanks. Alfahill
 

·
Premium Member
Joined
·
27,300 Posts
Along right side of engine bay.
 

·
Registered
Joined
·
1,233 Posts
The hydrocarbon dangers have been discussed a lot and I am well aware. I don't want to start that discussion again here, so this is the last post on the subject from me. I feel that there are some level of danger in everything we do, and the gallons of gasoline in the car are far more dangers from my prespective. The right mix of air and HC to burn this stuff isn;t easy to get. I have a heck of time sometimes getting a propane torch to catch with my spark maker!
FWIW, I'm also trying one of these alternative refrigerant. The car's A/C gets cold although not quite as cold as I like - still kind of experimenting!
 

·
Registered
Joined
·
273 Posts
Discussion Starter #13
Problem solved-expansion valve

Well, Steve was right as usual. I changed out the expansion valve, which includes some sort of a pressure relief valve (returns the refrigirant via a capillary tube to the compressor intake hose), and all is fine. I did find that the pressure relief valve on the old expansion valve was just slightly leaking. No need for a new compressor now, but I will get a new expansion valve in case this happens again. Thanks to everyone who helped with their ideas. Alfahill
 

·
Registered
Joined
·
503 Posts
Ah, Steve's great, but I think it was me that first advised expansion valve. :rolleyes:

Share the love!
 

·
Premium Member
Joined
·
9,811 Posts
Yeah, I am having the same issue. I think I have a stuck Exp. Valve. I am only getting at best 58˚F from the vents, when I use to get like 41˚F. A/C guys here says it is a bad expansion valve.
I have to admit I went the cheapy route on this one and installed an after market exp. valve and it went bad fast. I have a new Eaton exp. valve ready to go in. will update if this fixes my problem or not. I think I need cool air more than most at this point. LOL
J
 

·
Premium Member
Joined
·
27,300 Posts

·
Registered
Joined
·
3,724 Posts
So I just got a new receiver dryer installed and a Freeze12 recharge and am only getting about 55 degrees out of my L. Expansion valve is working so I don't know if the compressor is just not pumping like it used to or what.
 

·
Premium Member
Joined
·
27,300 Posts
So did you put too much oil in system? Total not to exceed 5 oz. for whole system. How much Freon did you put in - 44 oz for R12? How do you know expansion valve working?
 

·
Registered
Joined
·
3,724 Posts
So did you put too much oil in system? Total not to exceed 5 oz. for whole system. How much Freon did you put in - 44 oz for R12? How do you know expansion valve working?
I didn't do the work myself and just got the info from my mech so I don't have all the details right now.
 
1 - 19 of 19 Posts
Top