Getting ready to get the AC working - Page 3 - PeachParts Mercedes-Benz Forum

funola · #31 07-27-2010, 12:20 AM

Quote:

Originally Posted by Yak

Didn't you read my treatise on the CompressorWorks R4install? ...

I just did. Nice DIY write up!

Yak · #32 07-27-2010, 12:42 AM

Quote:

Originally Posted by funola

It's a very fat o-ring. more like 3.25 x 20.5 by the convention you're using.
The black o-ring in the pic actually looks pretty good after I boiled it, smooth with no nicks, not flattened or crushed. It was made with some good rubber in it's day. This o-ring came from the bad R4. There are 2 more in the good R4 which is in the car being pressure tested. They are holding pressure but I'd take them out to let them stretch out a bit then inspect them and put them back in if I can't find exact replacements.

I was about to say "that's 1/8 x 7/8" but then I found the Delco site:

"

During the 1988 model year, the design of the A/C Compressor O-Rings was changed from the standard “Round” type to an “Oval” type design
on all GM HR-6, R4 and V5 Compressors.
The reason for the design change was to improve the durability of this refrigerant joint, thus increasing your customer’s satisfaction with the
vehicle A/C System.
It is important to understand that due to the “Cross Section” shape of oval vs. round design, the Oval O-Ring does not completely fill the
machined o-ring grooves in the compressor rear head. A gap between the Oval O-Ring inner diameter and the machined groove inner diameter
is correct and expected.
In addition, the Oval O-Ring does not fit freely in the o-ring groove. The O-Ring must be coated with approved refrigerant oil and inserted all the

way into the o-ring groove prior to joint assembly.

http://www.acdelco.com/pdf/appcat_buyers/orings_gaskets_snaprings.pdf

You want the Santech MT0036-2 kit.

http://www1.autozone.com/autozone/accessories/Santech-2-pcs-7-8-in-green-HNBR-O-Ring-for-GM-A6-R4-LT-R4-H6-and-V5-oval-discharge-suction-ports/_/N-26fc?appQuestionId=4294832246&counter=29&itemIdentifier=147371_0_0_&nysQFromType=nysQuestions

funola · #33 07-27-2010, 01:01 AM

Very interesting. How did you dig that up? On page 299 of the acdelco pdf, why does that compressor head have so many ports? Are we talking o-rings for the same ports, i.e. suction and discharge or some other o-rings?

Yak · #34 07-27-2010, 01:16 AM

I think that's all the holes and ports and stuff on the compressor. Figure 4 holes for mounting bolts, one for the snap ring thing, two for suction/discharge. I don't know what the others are for.

#35 07-27-2010, 08:03 AM

Interesting thread. I'd love to join in, but I'm afraid that anything I would say would start a fire storm.

funola · #36 07-27-2010, 09:47 AM

Quote:

Originally Posted by 4thesporty

My new compressor works compressor (thanks for the tip YAK) came with the sealing washers. It came with three, two of which I used.

Well, I guess what Compressor Works told me is not true then? Too bad Yak's didn't come with the sealing washers otherwise he'd be up an running enjoying cold ac!

funola · #37 07-27-2010, 10:00 AM

Quote:

Originally Posted by Yak

I was about to say "that's 1/8 x 7/8" but then I found the Delco site:

"

During the 1988 model year, the design of the A/C Compressor O-Rings was changed from the standard “Round” type to an “Oval” type design
on all GM HR-6, R4 and V5 Compressors.
The reason for the design change was to improve the durability of this refrigerant joint, thus increasing your customer’s satisfaction with the
vehicle A/C System.
It is important to understand that due to the “Cross Section” shape of oval vs. round design, the Oval O-Ring does not completely fill the
machined o-ring grooves in the compressor rear head. A gap between the Oval O-Ring inner diameter and the machined groove inner diameter
is correct and expected.
In addition, the Oval O-Ring does not fit freely in the o-ring groove. The O-Ring must be coated with approved refrigerant oil and inserted all the

way into the o-ring groove prior to joint assembly.

http://www.acdelco.com/pdf/appcat_buyers/orings_gaskets_snaprings.pdf

You want the Santech MT0036-2 kit.

http://www1.autozone.com/autozone/accessories/Santech-2-pcs-7-8-in-green-HNBR-O-Ring-for-GM-A6-R4-LT-R4-H6-and-V5-oval-discharge-suction-ports/_/N-26fc?appQuestionId=4294832246&counter=29&itemIdentifier=147371_0_0_&nysQFromType=nysQuestions

The green o-rings I bought matches the description of the oval o-ring design. Does it actually seal better? Anyone know from actual experience? Larry? John, Greg?

vstech · #38 07-27-2010, 10:14 AM

sorry, no. I have no experience with the various orings on the ends. my first experience with the stepped compressor ports was saturday with Thayer's new compressor install. (that went well overall!)
speaking of this. his compressor failed. it looks like the crimped plate that holds the body of the compressor together just let go. is there no bolt holding the body of the compressors together? on a GM mount, the bolts go from the front to the back in 4 places, and all 4 bolts hold the compressor together. the MB mount attaches the bolts to the back end of the compressor, so there is nothing holding the body of the compressor together except the crimped over bracket.
is there a fourth bolt to hold this together that can be fed in from the front?

funola · #39 07-27-2010, 12:08 PM

Quote:

Originally Posted by vstech

sorry, no. I have no experience with the various orings on the ends. my first experience with the stepped compressor ports was saturday with Thayer's new compressor install. (that went well overall!)
speaking of this. his compressor failed. it looks like the crimped plate that holds the body of the compressor together just let go. is there no bolt holding the body of the compressors together? on a GM mount, the bolts go from the front to the back in 4 places, and all 4 bolts hold the compressor together. the MB mount attaches the bolts to the back end of the compressor, so there is nothing holding the body of the compressor together except the crimped over bracket.
is there a fourth bolt to hold this together that can be fed in from the front?

It's a reman? What brand again? Is it not made as well as the old GM Delco unit? The tendency these days is cut cost at the expense of quality and sell more in quantity by offering a low price.