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compressor sealing washer confusion

70monte on Mon October 06, 2008 7:25 PM User is offline

Year: 1992
Make: Chevrolet
Model: Cavalier
Engine Size: 2.2L
Refrigerant Type: R12
Ambient Temp: 74
Country of Origin: United States

Today I went to recharge the AC on my Cavalier. I had already replaced the compressor, accumulator, condensor, OT, and all new O-rings as well as 8oz of mineral oil. I tried vacuuming down the system but it would only go to 29 on the manifold gauge. Usually when I vacuum down a system with this pump(Robinair 6cfm duel stage) it always goes to 30. I closed the manifold wheels and shut the pump off and the pressure started to bleed off. I knew I had a leak but I couldn't imagine where. I took the lines apart at the condensor and the compressor and didn't see anything suspicious. Here is where I have a question.

The new AC-Delco compressor that I bought has the discharge port casing deeper than the suction port side but the suction side has a larger diameter hole in it. The end of the hose manifold that mounts to the compressor both stick out the same length but the suction side is bigger around than the discharge side.

The paper that came with the compressor said to use a green washer on the discharge side and the red washer on the suction side but the red washer will not go onto the part that sticks out on the hoses, its too small, and the green washer doesn't allow the part that sticks out to go into the hole on the compressor. Instead, I used the red washer on the discharge side and one of the thin silver washers on the suction side and it seemed like the hose manifold was even but I'm beginning to think maybe its not. I don't know where else the leak could be. Its a fairly large leak because of how fast the pressure bleeds down.

I'm really not sure which washers I should be using since the paper only says to use different combinations of the green and red washers depending on what your compressor ports look like and your hose manifold. The original compressor used two thin silver washers with one having a bigger hole in it than the other. The original compressor was the same depth where the washers sit in the compressor where as the new compressor is deeper on the discharge side.

Does anyone know or have a suggestion as to which washers I need to use? I have green, red, silver, silver with a larger opening, and one that looks a little darker than silver.

I spent all afternoon working on this with no results and I'm frustrated. Thanks.

Wayne

Chick on Mon October 06, 2008 8:08 PM User is offlineView users profile

Use the "thin" washer on the shallow side and a thick washer on the recessed side, you should be fine..Not sure of the colors though, I only use the thin and thick black ones..you want to make the back of the compressor flat across like the old one was..Hope this helps..

Appears you have a 5/8 hole and a 3/4 hole (washer sizes)

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

GM Tech on Mon October 06, 2008 10:27 PM User is offline

You had it right- red in the discharge (deeper side)- and a standard thin bigger diameter one on the suction port... keep it level across is the main intent- I never read the paper- just use what works- don't like to get confused with the instructions... common sense prevails. If you can't find the leak under vacuum- slip a little charge in it- and listen for a leak that big....won't take much..

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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......

70monte on Mon October 06, 2008 10:27 PM User is offline

Chick,
Thanks for the reply. I do believe that I have the 5/8 and 3/4 hole. I'm pretty sure I need to use the thin washer for the shallow side but I don't know what to use for the recessed side. I have three thicker washers that came with the compressor. The green washer is the thickest, then the red, then the darker silver one. With the red washer, the hose manifold looks to be level but its kind of hard to see the back of the compressor. I guess I will try the darker silver washer and see what happens. If that doesn't work, I don't know what. The paper that I received with the compressor does not mention using the silver washers at all, just the red and green. I'll let you know what happens tomorrow.

Wayne

70monte on Mon October 06, 2008 10:37 PM User is offline

GM Tech,
Thanks for the reply. I have the washers installed like you stated. I just remembered and went outside to check my other 92 cavalier that I switched over to R134a two years ago. I'm using the same compressor now as I did then. From what I can tell, I used two silverish looking washers on that car. I'm guessing that I used what I've referred to as the darker silver washer. I had both red and green washers left over from that repair so I guess I didn't use them. I'm going to try the darker silver washer tomorrow and see what happens. If that doesn't seem to work, I will charge it a little and see If I can find it that way. Thanks for the suggestions.

Wayne

Chick on Tue October 07, 2008 6:26 AM User is offlineView users profile

Just a note, GM tech can do those in his sleep, Follow his directions..use the "thin" 3/4 in the shallow, and the 5/8 red in the recessed...As he suggested.. Also, if it still doesn't hold vacuum, then use standard leak detection methods with pressure in the system..Hope this helps..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

mk378 on Tue October 07, 2008 10:21 AM User is offline

GM loves to make things more complicated than they need to be. You probably have a old-style flat compressor on the other car, thus the two washers the same. The difference in washer thickness needs to match the difference in height of the compressor ports. Also like Chick said, if it seems the washers are right, don't assume the leak is at the compressor ports.

You can use a little R-134a for a static (compressor not running) pressure test then evacuate it and charge with R-12 once it doesn't leak. Always pressure test an R-12 system before charging with R-12.

70monte on Tue October 07, 2008 1:32 PM User is offline

I replaced the washers again at the compressor, using the thin 3/4 one on the suction side and the slightly darker thicker 5/8 one on the discharge side. The red washer and the darker silver one appear to be the same thickness.

I still have a big leak. Changing the washers at the compressor did not help. Just to be clear, the compressor that I'm using on my other cavalier is exactly the same as I'm using on this Cavalier with the same deeper recess on the discharge side.

I guess my next step is to recharge with some R134a and see if I can hear where its leaking from.

Wayne

70monte on Tue October 07, 2008 5:01 PM User is offline

Well, I found and fixed the leak. One of the lines going into the evaporator was leaking. When I took the line off, a section of the O-ring was cut out. I'm not sure how that happened but I got it fixed anyway.

Now I have another problem. I can't get any refrigerant into the car. The R12 yellow hose doesn't seem working right even though it drew vacuum through it. When I first tried to bleed the air out of the yellow line, I got what felt like air but no refrigerant ever came out. finally the air stopped coming and than nothing.

I tried taking the yellow hose completely off the manifold and attach it to the can tap and didn't get anything out either. When I press the valve down on the can tap, refrigerant will come out so I know the can tap valve is working. Somehow either the valve in the end of the yellow hose is bad or the can tap R12 port is not fully depressing the valve in the end of the yellow hose. I'm not sure what to do at this point. My R134a yellow hose will not work on my R12 manifold.

I guess for now this car will remain unfixed until I can figure out what to do.

Wayne

Chick on Tue October 07, 2008 5:58 PM User is offlineView users profile

check for a shrader valve in the yellow hose.. You may not need it, and it could be on backwards?? If refrigerant flows thru it, it should flow thru the manifold gauges right???

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

70monte on Tue October 07, 2008 6:21 PM User is offline

Chick,
there is a shrader valve in the yellow hose. I can push down on it with a screwdriver. I don't know if its in backwards or not but it looks exactly like the shrader valve in my R134 yellow hose. Refrigerant is not flowing through it. When I attached the yellow hose to the can tap without the other end being attached to the gauges, nothing came out of the end of the hose. Thats how I determined the hose is not working correctly.

After I had pulled a deep vacuum and attached the can tap, I opened the low side to pull refrigerant into the system. The low side gauge only went to about 10psi and stopped and won't go any higher. Normally when I do this same procecure with my R134a gauges and hoses, the low side pressure goes all way to about 70psi and than comes down.

I don't have a shrader valve puller to take the valve out of the hose.

I noticed that the ends of the two ports coming off of the can tap are different in that the part that sticks out past the threads that compresses the shrader valve is shorter on the R12 port than on the R134 port. I'm wondering if the schrader valve is not getting fully depressed when its attached to the can tap.

Have you ever had a problem like this? My can tap, gauges and hoses are all Robinair so they should all be compatable.

Wayne

Chick on Tue October 07, 2008 7:03 PM User is offlineView users profile

Yes, get another hose, color doesn't matter as long as you know where it's going, and use that as long as it doesn't have a shrader valve. You need them on the ports obviosly, but not on the yellow hose if you're using a manifold set, be sure to shut the wheels when you remove the vacum pump, and bleed some refrigerant thru it before charging to remove the air..

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

70monte on Tue October 07, 2008 8:07 PM User is offline

Chick,
thanks for the info. I just remembered that when I put a can of R134 in the can tap to check for my leak, the refrigerant went into the system fine so I don't understand why the R12 won't go in. Also, if I don't have some kind of valve in the end of the yellow hose, what will depress the valve in the can tap? Actually, I don't think the valve in the end of the yellow that hooks up to the can tap is really a shrader valve. I'm not sure what you call it. Its not the same type of valve that is in the can tap or the ports on the car itself.

I don't have access to another R12 hose and no one around sells them anymore. I'm either going to have to order a new hose or put a R134 conversion kit on my R12 ports so I can use my R134 gauges and hoses.

This whole thing has turned into a big hassle. The second day of work with no results.

Wayne

Chick on Tue October 07, 2008 8:30 PM User is offlineView users profile

It's not a shrader valve, just a depressor, but if you're using a 30lb tank, it won't have a shrader valve either.. Check all the connections on your hoses, something is wrong and might turn out to be a simple thing, but I can't see it, so I can just guess.. You can use a pick to remove the rubber around the depressor and then remove the depressor. As far as the shrader valve in the can?? are you using a side can tap? the depressor should depress that shrader valve.. Maybe you're not depressing the port shrader valves??

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Chick
Email: Chick

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Freedoms just another word for nothing left to lose

70monte on Tue October 07, 2008 8:45 PM User is offline

I am using a side can tap that has shrader valves in both ports. If I take the depressor out of the yellow hose then there will be nothing to depress the shrader valve in the can tap.

What I don't understand is that when I had the can of R134a in the can tap hooked up to all the same hoses, the R134 went into the system because I could hear where it was leaking out. I did forget to look at my low side gauge to see how high the pressure went up.

I'm assuming the port shrader valves on the vehicle themselves are working because the R134 went in and when I had a leak in the system, the gauge starting losing pressure as soon as I shut off the vacuum pump.

I have another can tap and will try that tomorrow. I attached my yellow hose to this empty can tap and was able to blow and suck through it, although the flow wasn't very much. Thanks for the suggestions.

Wayne

70monte on Wed October 08, 2008 7:18 PM User is offline

Well, I finally got the AC charged. I think the end of the R12 port on my can tap wasn't opening the depressor on the charging hose. I used my other can tap and the refrigerant flowed into the system like it should. I'm not sure if I got the full amount of R12 in it or not.

I started with an empty system and started with a new can but it seemed like whenever I would change cans there would be a little bit of refrigerant that would come out when I took the can tap off.

The ambiant temp was about 72 degrees in the garage and my low side was 29-30psi and the high side was 160-165. I might be a little undercharged but my vent temps at idle were 37 degrees. I'm happy with it so far but we will see how it goes and hopefully I fixed the leak. The needle stayed steady when I let it sit between the two 30 min evacs I did.

Wayne

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