Question for the R4 compressor experts - PeachParts Mercedes-Benz Forum

otto huber · #1 02-20-2016, 10:08 PM

Today I installed a Harrison R4 compressor on my 1981 300SD. The two washer/seals for the back of the compressor which fit the stock Behr just fine don't fit on the Harrison. I found these two listings on Ebay:

Compressor Shaft Seal Kit for GM Harrison A6 R4 w Steel Seal Murray 207253 | eBay

Four Seasons 24338 Sealing Washer Kit 5 8 GM A C Compressors Harrison A6 LR4 | eBay

Since the first listing says that the seals are for both the A6 and the R4, I was hoping that the seals on the second listing might also fit a Harrison R4. Does anyone know exactly which seals I need? Thanks

LNGfish · #2 02-21-2016, 06:39 AM

I did not click the links but I recently installed a new R4 on my 82 300SD and had those flat washer seal problems like you are having.

To make a long story short I had a variety of used but good flat washer seals and through trial and error and an extra can on Juice I got a good seal no leaks.

After all this done, I walked into the local CARQUEST store and they had a nice box of all sort of seals for GM R-4.

This box was $12 and box was see through and like 1" X 1" X 4". A snap box.

I didn't buy it because I did not need it but I'd suggest you look to get this Universal Seal box for GM for R-4.

Try NAPA?

Steve

mannys9130 · #3 02-21-2016, 04:49 PM

I'm not sure why people would reinstall an R4.

Sanden conversion is a no brainer.

Hit Man X · #4 02-22-2016, 08:37 PM

I think I used black and yellow on the stepped ports when I was still dicking around with R4s. Never could make them seal properly, one needed a fitting pressed in the manifold hole side from what I recall.

This was on a new in box 'Compressor Works' unit. Cooled great on R12 (probably same on R152A) just leaked constantly out of the ports.

Good luck, hope you can make the thing seal.

BillGrissom · #5 02-22-2016, 09:58 PM

Quote:

Originally Posted by mannys9130

... People are allowed to be wrong.

Count me "wrong". My 1985 has a Sanden H13 on Rollguy's brackets. My 1984 has the R4 that came with it and will stay such because I have another used R4 (or 2?) plus a new R4. Both cool the same, best I can tell (given the quirky climate controls). Also "wrong" because I use Duracool hydro-carbon refrigerant and PAO 68 oil, which could be why my R4 lasts thru our severe Central Valley summers (>110 F).

I went thru the R4 sealing washers issues last summer, and share my notes below. I found the washers at a local NAPA (using their online PN search), and they were in an old box. I am also trying to attach a pdf from Four Seasons that details it. But, this is for a factory Harrison. Apparently, many replacement compressors have different seal pads, so you might need to keep researching.

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

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

otto huber · #6 02-22-2016, 10:18 PM

Quote:

Originally Posted by BillGrissom

Count me "wrong". My 1985 has a Sanden H13 on Rollguy's brackets. My 1984 has the R4 that came with it and will stay such because I have another used R4 (or 2?) plus a new R4. Both cool the same, best I can tell (given the quirky climate controls). Also "wrong" because I use Duracool hydro-carbon refrigerant and PAO 68 oil, which could be why my R4 lasts thru our severe Central Valley summers (>110 F).

I went thru the R4 sealing washers issues last summer, and share my notes below. I found the washers at a local NAPA (using their online PN search), and they were in an old box. I am also trying to attach a pdf from Four Seasons that details it. But, this is for a factory Harrison. Apparently, many replacement compressors have different seal pads, so you might need to keep researching.

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

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 Bill. I'll take this information to my NAPA store and see what I can get. I wish that I figured this out before I mounted the compressor.

mannys9130 · #7 02-22-2016, 11:45 PM

Quote:

Originally Posted by BillGrissom

Count me "wrong". My 1985 has a Sanden H13 on Rollguy's brackets. My 1984 has the R4 that came with it and will stay such because I have another used R4 (or 2?) plus a new R4. Both cool the same, best I can tell (given the quirky climate controls). Also "wrong" because I use Duracool hydro-carbon refrigerant and PAO 68 oil, which could be why my R4 lasts thru our severe Central Valley summers (>110 F).

Definitely. Hydrocarbon refrigerant's been beat to death already so I won't even attempt to touch that one... I'm glad to hear your Mk. 1 hand can't tell the difference between the two cars. My points still stand. Once you have to fuss with an R4, rip it out and put what's much better in its place. In Tucson, we see extreme temps that reach 115* F and subpar AC systems make themselves evident very clearly.

leathermang · #8 02-24-2016, 01:48 PM

Automotive Air Conditioning is HARD.

Automotive Air Conditioning on a 20-30 year old Mercedes Diesel is VERY HARD.

There are many potential reasons for this. Most people have not owned their car AND been the only AC person to touch it... or they might be but did not know all they should have when they first messed with the AC decades ago. No one is born with this knowledge and before the internet much of the necessary information was kept secret by the Factory and Dealerships for their own financial gain.

Blanket statements often leave out a dozen unknown variables which are simply not discoverable by any means.

I am one of the few people on this forum who really understands how hard the task Rollguy took on is. It is and was Noble Goal. When I looked at doing the same thing I chickened out.... it could easily take hundreds of hours of testing and redesigning and multiple times of starting ALL over.
Saying that choosing to put the Sanden on is a ' no brainer' is not correct. When I had the attitude that the R4 Compressor was ' evil ' I called my AC Guru in San Antonio and talked to Trey ... the owner of

Auto Repair in San Antonio, TX | Carlisle Air Automotive

He immediately disabused me of the notion that the R4 was automatically unfit for use with the newer , higher pressure , R134a .... saying that it was used just fine on millions and millions of non Mercedes and that the TRICK was to use a later serial number R4. I shared that information in a thread in the archives.

There are lots of people who look at the dynamic AC system and think false things... an example is that ' it just leaked a little' , the assumption being it is and was under pressure.... so therefor my oil and refrigerant has not been mixed with oxygen from the atmosphere.... ANY LEAK in the system is considered by professionals as having contaminated the oil. The reason this is important is that the acid formed by the mixing of the oil with oxygen can corrode the inside of the metal parts exposed to it.. this CAN mean that little flakes of metal make their way to important bottlenecks such at the TXvalve... which regulates the phase change from high pressure liquid refrigerant into a spray inside the evaporator... air passing over the fins of the evaporator are thus cooled.

That is another factor many people gloss over .... the system works on Air Passing over two items... both with fins... one is just as important as the other.. they are a team... you can have the entire system perfect... except for 20-30 years of dog hairs or whatever blocking the flow of air across the evaporator under your dash and you have squat for Air conditioning....

Worse than Squat... you have Expensive Squat and you may have caused the problems with that rest of the 'now perfect' system because it had to work ten times harder to provide you will cool air than it would have had your evaporator fins been clean...

I think the evidence on Rollguy's initial kit offering is that his welds were ' cold' meaning not enough penetration and that they might have been under designed in terms of bracing. I suggested at one time he check with some of the Welding forums and get their advice...

Then there appeared to be a problem which caused the inability of the belt to be tightened enough or stay tightened enough.. I don't remember.....
I think there was a difference in the original pulley and the new pulley in terms of the v angle or something.... all of these types of things are normal to a really hard project of this type... there is little room to work in and conflicts of all sorts can arise.
Had I had the guts and money to attempt this kit conversion I would have tried to find a way to place an idler pulley in the system... if there is room... it can overcome things like not having enough radial contact between the belt and the AC compressor. It can help if there is a problem with distance of movement available to both apply and tighten the belt properly. On some cars this friction need was dealt with by using two ( matched, they were sold in the same package ) belts ... I believe my old Dodge pickup truck used that on the vibrating York compressor it had.

People simply don't understand how severe the working environment is inside or outside the AC on our diesel engine cars. Constant vibration ,mixed with wide changes in temperature, is relentless and extreme.

I hope that Rollguy continues to tweak his kit to where it really is a ' no brainer' ,IF one has the money to chose that option, at some time in the future or perhaps it already is... I have not looked at the updates in a while... the goal really was aimed at a real need which had the potential for saving many of these cars from the salvage yard... There are places where people NEED Air conditioning and I live in one of them.

I regularly see threads where people are thinking some ' bullet ' ( I did not use the word magic because they are looking at one actual potential needed action or part )... they do that... ignoring the bigger picture which I have tried to describe... and sometimes it works just fine... or may work just fine for that season... and then they have to start over.... and even then may not address the larger and necessary parts of the AC system.

I repeat :

Automotive Air Conditioning is HARD.
It is physics both extreme and subtle at the same time.
read and study all the legit sources you can find.
Get a copy of a local community college HVAC textbook and study the basics before putting lots of money into your system...
Don't skip steps which are critical to the inside of the system..
The inside needs to be Clean.
The outside needs to be Clean.
It needs to have the correct amount and TYPE of oil which matches your refrigerant.

Automotive Air Conditioning is HARD.
Try to be logical in how you attack the problem.
You do not want to do one thing which has to be repeated to be correct because you did not make a list or read enough about AC theory.

Automotive Air Conditioning is HARD...
It will take persistence and LOTS of it...
in addition potentially ' Lots' of money to get it working right in a condition where it works right for years ( my goal is 7 years before any attention needed ).

The AC thread in my signature might be worth reading...

babymog · #9 02-24-2016, 02:08 PM

Thanks for your knowledgeable, informed, and non-judgmental response, this thread needed it.

dude99 · #10 02-24-2016, 04:11 PM

@leathermang
Great post. I was rather hoping you would pop by this one an inject some info

rrgrassi · #11 02-24-2016, 06:06 PM

The Hancock Ind new, not rebuilt R4 has been on my for 10 years and 125k miles now. No issues with it. I used BG Fridgi-quiet oil. Is the R4 junk? It all depends of who built it.

ROLLGUY · #12 02-24-2016, 07:24 PM

Although I am biased, I say that the O P is doing what his time and budget allows, so leave him alone. I see no problem with using up all the old, cheap R4's he can find. If he has spares, and the time to replace them, more power to him! Heck, I have several compressors I have removed to install Sandens that I will give for free for just the cost of shipping. I could also look at it this way: people like this will use up all the remaining supply of R4's, and the only option left for our cars will be the Sanden! (I say that in jest). I will also add, that when an R4 goes bad, it spreads it's innards throughout the system. A thorough flushing and new drier is required when this happens. If someone is willing to go through this each time the R4 is replaced, then have at it! Either way, I will be here to provide the final solution for any and all your R4 woes.

leathermang · #13 02-24-2016, 07:38 PM

Rollguy, You bring up a good point about filtering...
it is possible .....and I highly recommend... that people put a filter between the compressor and the Condensor.... particularly so with any new Parallel flow condensors as I have read they have even smaller tubes than a regular condensor.. but either way it could save a LOT of money if the current R4 BLACK DEATH's ...
Rollguy, since you are 'here' what is the current state of your Sanden kit ?

leathermang · #14 02-24-2016, 11:20 PM

The original post indicates the system is still open..... waiting for decision on compressor seals..
Thus it would not involve ' going backwards' at this point to install a filter if he wanted to....

mannys9130 · #15 02-25-2016, 12:44 AM

Circular nonsense Greg.

Sanden > R4 in a plethora of ways. Those who choose to reinstall an R4 can do so with the understanding that they're not utilizing their system to its full potential or efficiency, and that they'll be back doing the same enormous job of flushing and replacing things soon when the R4 grenades again. Plain and simple.