A/C compressor sealing washer question

[OdeToBob]

Hi all,
I've inherited my father-in-law's 1999 Tahoe a couple of years ago and I'm finally trying to sort out the A/C (which he was in the process of trying to revive when he passed away).
I, unfortunately, didn't get to talk with him about it before he passed.
I knew that he had replaced the compressor but when I inherited it, the system was empty.
I've flushed all the flushable lines and replaced orifice tubes and the rear expansion valve and the accumulator/dryer.
The system held shop air fine at about 60 psi.
I vacuumed it down and it's held vacuum fine for the past week or so.
I went to charge it up today and was immeadiately met with a HUGE leak at the high side connection between the compressor and the muffler line that runs to the condenser.
At this point, I think I either don't have the correct sealing washer or a spacer or something, or that the replacement compressor isn't compatible with the OEM line connector block.
Can anyone advise what I should be looking for/verifying/changing?
Thanks for the advice
-Bob

 

[exp500]

Take a pic of sticker on AC dryer for charge weight and RPO sticker in glove box. Maybe you got wrong parts.

 

[Eman85]

I'm operating on memory so I can't swear this is correct. Fit the manifold hose to the compressor with no seals and see how it sits. I think one side seal is thicker than the other.
Side note I wouldn't blow shop air into a system that I wanted to make work. Shop air is contaminated with moisture, AC systems don't like moisture.

 

[OdeToBob]

Take a pic of sticker on AC dryer for charge weight and RPO sticker in glove box. Maybe you got wrong parts.

Thanks for the tip. I did get the info off the old dryer but didn’t know about the RPO. I’ll take a look for it and double check what I’ve bought.

 

[OdeToBob]

I'm operating on memory so I can't swear this is correct. Fit the manifold hose to the compressor with no seals and see how it sits. I think one side seal is thicker than the other.
Side note I wouldn't blow shop air into a system that I wanted to make work. Shop air is contaminated with moisture, AC systems don't like moisture.

Definitely has two different heights on the manifold fittings. One (low side) had a thick red washer and the other (high side) had a metal washer with a rubber center.
I think it’s possible that my late father-in-law installed both of these though. So I’m not confident they’re correct/stock.
There’s a kit that autozone sells with a couple of differing colors and thickness washer/gaskets. I’m thinking that’s got the washer/gaskets I’m needing.

Also, thanks for the note on shop air. I hadn’t considered that that might not be the best thing to push into an A/C system. I’ll refrain from doing that in the future and hope I haven’t done too much damage. Would you recommend doing anything at this point to help myself out? Vacuuming the system for longer? Or…??
Thanks again,
Bob

 

[Eman85]

Pulling vacuum for a long time helps to eliminate any moisture so it wouldn't hurt. I like to shut the gauges and leave them for a long tome to see if there is any drop in readings. Both washers should have a rubber center and fit over the part of the manifold hose. You say you flushed. Did you put oil into the system? I distribute the oil in each area as I assemble, I use a veterinary style syringe to measure and put the oil in. Be sure to use the correct weight oil.

 

[east302]

Here is the GM/Delco part number for the washer set…

 

[OdeToBob]

Pulling vacuum for a long time helps to eliminate any moisture so it wouldn't hurt. I like to shut the gauges and leave them for a long tome to see if there is any drop in readings. Both washers should have a rubber center and fit over the part of the manifold hose. You say you flushed. Did you put oil into the system? I distribute the oil in each area as I assemble, I use a veterinary style syringe to measure and put the oil in. Be sure to use the correct weight oil.

I've been pulling a vacuum for an hour plus each time I had to open the system. Hopefully that'll help.
Thanks for the advice.
I went down to a pull-a-part yard and checked a couple of similar trucks just to be sure. Looks like both sides needed the thinner metal/rubber washer you mentioned. My father-in-law had added the red one by mistake I suppose.
Everything seems to be holding vacuum fine now and I filled the system with 64 oz of freon this afternoon. Good pressures on the gauges (for 58 degree weather) and no leaks that I can see with the uv light. Everything is blowing very cold, including the rear ac.
I did spread 11oz of pag150 throughout the system when I was refitting everything with the new o-rings. Thanks for mentioning that though.
This was the first time I've ever touched anything related to a car's AC. I've learned quite a bit from reading things on this forum and I sincerely appreciate the replies here on this last bit of my adventure.
Here's hoping things are still solid when Tennessee gets hot again!
-Bob

 

[OdeToBob]

Here is the GM/Delco part number for the washer set…

View attachment 416255
View attachment 416256

Appreciate this! That's exactly what I ended up using.

 

[Eman85]

Glad it worked out. People think that pulling a vacum is only to test the system. It is to remove any moisture from the system. Water boils at a much lower temperture under vacum.