A/C Question W123 - 1985 Mercedes 300D
 

Hey guys,

I'm installing my A/C compressor and the kit comes with 3 orings. I was just wondering which one's I should use for input/output? Also why is there 3? Sorry for the noob question. This is a Spectra Premium A/C Compressor (reman R4) and a below screenshot is of the 3 orings and the compressor itself.

I saw the following for another brand for A/C compressor, however I'm not sure if it's for mine as well and I don't understand it. "GM Radial R-4 version Compressors having stepped ports require the the following seals be installed in the following manner : The large brass seal is only for the suction port. The green seal is to be used on the discharge port. The short(er) of the two sleeves is to be used in conjunction with the green seal. This centers the seal, which is essential to prevent leakage. The two other seals in the kit are not applicable for Mercedes. These seals will only be used in compressors having a stepped port configuration. See 24 342"

Thanks,

Marco

https://i.imgur.com/a7spqFy.png

https://i.imgur.com/hx5YoJO.png

When I bought an R4, it did not come with the correct seals. I sourced a TEM 407292 Yellow seal at the local NAPA store for the suction side and used a furnished green seal on the discharge side. I didn't use the insert sleeves, as it appeared probable that they would eventually wind up being ingested into the compressor.

Thanks for the response, what exactly is an insert sleeve? From looking at the above pictures, I know it's just a guess but would you say these are the correct seals?

Your best bet is take measurements of the thickness of the seals and the seats in the compressor and determine which are the correct seals. The seal has to "crush" some in order to work so it has to be thicker than the depth in the seats. Choose the 2 seals that would protrude an equal amount.

As for the insert, it is a thick metal bushing that goes in one of the seals and is held on by friction only. I have heard if it is not in there tight, it could dislodge itself, fall inside the compressor, destroying it.

Thanks so much, I’ve noticed online that every kit comes with 3 seals.

My question is why 3 seals? It’s very confusing.

https://m.ebay.com/itm/NEW-Mercedes-W123-300D-300TD-A-C-Manifold-Seal-Kit-Four-Seasons-900-130-06-15-/360884141525

There’s an example. Grr. Why 3 seals!! There’s only a input and output.

The original compressors had Orings, and both ports were even (not stepped). The newer compressors have stepped ports, but the manifold on the 'Benz is flat (for original compressors with Orings). I believe that only new style compressors (stepped ports) are available new or as rebuilds. The GM R4 is a very popular compressor, and is used in many applications. When a new or rebuilt unit is sold, it is shipped (or should be) with every seal that is used, so it will work with any application.

Thanks for the reply Rollguy. From the below documentation, what "Hose Block Side View" would you say that I have on the W123?

https://i.imgur.com/XLz5AUk.jpg

https://i.imgur.com/XHpFu6k.jpg

I would say #2 if it is talking about the manifold being the "hose block".

The "heavy" R4 compressors with the big clutch coil use o-rings. You can still buy them as rebuilts. I bought one for my 85 300D. You can see pics of it here http://www.peachparts.com/shopforum/diesel-discussion/387054-4-seasons-remanufactured-r4-compressor.html

To confirm, it's #2 in the diagram with the 3/4" fitting for both input and output?

It is the only diagram with a flat face, so it should be correct.

Per the Tech Tip sheet, seals B (YELLOW) and E (GREEN) are what I used. (My compressor was furnished with two E's and one F.)

Has been answered many times - yel & grn washers. I didn't read all above, just repeat info below I have posted before:

Suction port:
Four Seasons 24358, yellow
NAPA PN 407279
AutoACRepairs PN GA4508, $3
GM PN 2724888
1.32" OD (33.2 mm) x 0.12" th (3 mm), ~0.585 " ID
compressor hole recessed ~0.08"

HP outlet port:
Four Seasons 24357, green
NAPA PN 407278
AutoACRepairs PN GA4506, $3
GM PN 2724890
1.18" OD (29.9 mm) x 0.216" th (5.5 mm), 0.61" ID
compressor hole recessed ~0.16"

Included in some kits, but not used:
Four Seasons 24356, red
AutoACRepairs PN GA4507
GM PN 2724889
1.18" OD (29.9 mm) x 0.15" th (3.8 mm), 0.61" ID

3-seal kit (red, grn, & yell washers, w/ inserts, use only grn & yell):
Four Seasons 24342
AC Delco PN 15-20058
AutoACRepairs GA 4504-KT, $9
GM PN 2724887
O'Reilly's PN 24342 $15, in stock at 2421 Del Paso Blvd

Red & grn washers only:
CompressorWorks PN 620230

Oil:
Total system 8 oz
Makeup for:
drier 0.3 oz
evaporator 1.4 oz
condenser 0.7 oz
used compressor 2.4 oz
new compressor 6 oz

Thanks, this will save YET another trip to my A/C Shop as they've been having trouble getting the compressor sealed properly. To confirm, all brands of the new R4 Compressor that have the stepped ports should only use the Yellow and Green washers and not the 2 black, 1 red given to be by the manufacturer?

eCatalog - Product

Napa has confirmed they have them. So no matter what was given to me, I'll use the noted/suggested yellow and green washers then.

Okay just picked up the new noted orings (FRONT), WOW they are larger then the ones sent with the A/C compressor by Spectra Premium (BACK).

https://i.imgur.com/4WGSGdT.jpg

Why doesn't the manufacturer SEND the proper orings for the make/model of the car? One has to do such extensive research and forum hunting to find these two proper seals for the R4 compressor for the W123. I can't imagine how many shops, people are probably using the incorrect one.

I doubt anybody here knows "all brands" and variations of R4 compressor out there. Best to measure the depth of the recesses. I gave above the dimensions for a new R4 I put in my 1985 300D.

Personally, I prefer the O-ring groove type, since O-rings aren't a treasure hunt. When I got a few sealing washers from NAPA, it was the only box on the shelf and had been sitting there for decades, so the next guy will get "not avail".

If an AC shop is doing the job, and dumping this search on you, I would question their professionalism. The R4 was used in a gazillion GM vehicles, so they should know all about them.

The front ones do look larger than the back ones, but that is to be expected in a photo. Seriously, what dimensions are larger? O.d. i.d. ?

Dimensions for seals are listed in post #8.

The recessed port compressors are the same. It's the hose blocks that are different from one vehicle to the next. The W123 hose block was not designed for the recessed port configuration to start with. In my experience, getting a leak-free seal with the recessed port compressor is a challenge. Much more so than with the original o-ring design.

Pretty much true for repairing or re-designing anything on all cars. Most people are too lazy so trust a "professional", but that often doesn't work out because they can't afford to do the research. Most of my relatives go thru cars like you wouldn't believe, usually trading one problem for another. Being an engineer, I am used to digging thru drawings and specs and double-checking everything. If not, things like the Apollo 13 incident happen - 12 VDC relay left after controls were upgraded to 24 VDC, overheated and blew up oxygen tank. At least your M-B stays grounded where failures are more benign. I usually verify parts against photos on rock's site, ebay, Google Images, and download catalogs from Gates, Goodyear, SKF, ... As you do find info, post it here for everyone, and smart people will file it away.