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Posted By: Scubasteve Gmc ac issue - October 19th 2018 11:59 pm
I have a 93 gmc shorty. Today i bought and installed new seals on the back of the compressor where the hard lines mount. When i went to charge the lines its still leaking there. I cleaned both surface areas before installing and double checked the seal part number. I am scratching my head now, any ideas on whats causing this?
Posted By: CatFish Re: Gmc ac issue - October 20th 2018 2:13 am
Are you sure it's the lines/connection that's leaking?
There is a plug (held by a cir-lock clip) in the rear of the compressor that has a o-ring seal. If you have a rear brace that connects the compressor to the intake manifold that plug will be hiding under it. Take out the two bolts holding the brace and you'll find it. (It will look similar to a small freeze-plug under the cir-lock.) I have had this spot leak many times before and drive an electronic leak detector nuts.
Posted By: Scubasteve Re: Gmc ac issue - October 20th 2018 2:29 pm
It was leaking around that area. I do remember seeing what looked like a small plate bolted to a brace at the bottom rear of the compressor. Ill check it out hopefully thats it. Thanks
Posted By: Bullet Re: Gmc ac issue - November 23rd 2018 11:55 pm
Those compressors are notorious for developing a leak between the front half of the case and back half. Try to run your hand under the bottom of it in the center and see if there's any oil. There is a different design compressor made to replace it, I got mine at O'Reilly's, it was called a "problem solver" at the time.
Here is a couple links, the first is the style that develops leaks, the second is a new one piece case design.
https://www.oreillyauto.com/detail/...r-new/88969/5777370/1993/gmc/g1500?pos=0
https://www.oreillyauto.com/detail/...r-new/58969/5777274/1993/gmc/g1500?pos=1
Posted By: thevolvokid Re: Gmc ac issue - December 30th 2018 3:43 am
Originally Posted by Bullet
Those compressors are notorious for developing a leak between the front half of the case and back half. Try to run your hand under the bottom of it in the center and see if there's any oil. There is a different design compressor made to replace it, I got mine at O'Reilly's, it was called a "problem solver" at the time.
Here is a couple links, the first is the style that develops leaks, the second is a new one piece case design.
https://www.oreillyauto.com/detail/...r-new/88969/5777370/1993/gmc/g1500?pos=0
https://www.oreillyauto.com/detail/...r-new/58969/5777274/1993/gmc/g1500?pos=1


Sorry to hi-jack the thread a bit, but does the 58969 (second link) fit in a 95 Chevy G20 application? I'm thinking it would but would love some insight on it.
Posted By: jcd74 Re: Gmc ac issue - December 30th 2018 11:04 am
If you can find, buy, borrow the equipment. Use a good set of gauges, and a vacuum pump, Pull a vacuum in the system, while it is pulling down tap on the compressor now and then to get any gas in the oil out (it will ruin the test). Pull it down to -28 on the low side gauge and let it sit for 24 hours. If it holds no leaks! While a pain in the ass, it's worth it to pull the compressor so you can look for problems. If you take it out change the oil The plug that Catfish mentioned. Keep in mind you have to use right oil for what ever gas you decide to use, the same goes for the seals on the refer lines at the compressor. I got a new compressor for my 89 and it came with a mixed bag of seals. They varied from gas used to type of refer line block it has.
Posted By: thevolvokid Re: Gmc ac issue - July 14th 2019 7:55 pm
I replaced the orriface filter at one point and found it to have metal shavings in it. I've decided it'd be best to replace the compressor with the redesigned unit, and possibly the condenser. The. I'll vac the system down etc etc.
Posted By: Scubasteve Re: Gmc ac issue - June 17th 2020 12:01 pm
I know this is an old post but life got in the way and Ive just been living with the ac not working. But I finally have some free time to work on my gmc and I finally found the problem with it. The main ac compressor line is leaking on one side. My question is are the gasket surface areas on the line supposed to be offset? The one side is at least an 1/8 further out than the other causing it not to seal. Are the seal different thinkness size because the ones i have are both the same thinknesses? Or do I have to get a new line?

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