Question for the R4 compressor experts - Page 2 - PeachParts Mercedes-Benz Forum

sixto · #16 02-25-2016, 12:50 AM

Quote:

Originally Posted by mannys9130

I'm not going to swing on this. The R4 is obsolete, inefficient, and doesn't belong in any AC rebuild. The R4 was done away with when MB introduced the W201. The 84 diesel and all 85+ models got much better compressors. The R4 was still in use by others, so why did MB stop using it? Maybe because it's no where near as good as the replacement.

Anyone who's seen Otto's car admires how original it is. I'm not going to make a compressor recommendation for him but I fully appreciate his pursuit of an R4.

Sixto
83 300SD... call me scarecrow

leathermang · #17 02-25-2016, 12:55 AM

If they clean the system properly this time they may not have it explode. Lots of them working just fine ... we get a skewed picture HERE when people are having problems.. no one comes on just randomly and says...."" I just wanted to stop by and report that my R4 is working just fine... cheers, later.... ""

ROLLGUY · #18 02-25-2016, 09:58 AM

Quote:

Originally Posted by babymog

The experts have made their recommendations, the troll has made his, this thread needs to close.

Yes, what happened with those manifold sealing washers? I too had a major problem finding the right combo when I did my first R4. If you have access to a dry gas to pressurize the system, you can try different ones to get the right combo. There is no sense charging the system every time, thinking you have it sealed (don't ask me how I know this :-).

ROLLGUY · #19 02-25-2016, 10:06 AM

Quote:

Originally Posted by leathermang

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 ?

One of the first few systems I retrofitted was on my neighbors TD. It took nearly a full quart of A/C flush solvent to get the hoses to run clean (evaporator and condenser still online) because of that "Black Death". I will try to find a photo and post it, it will blow your mind. I have not seen so much black stuff come out of a system as I did with this one. We also added a filter for extra protection. Yes I agree that a filter is a good idea when going with a P F condenser. It is not that hard to do, especially on the P F installations I do where new hoses are made anyway.

leathermang · #20 02-25-2016, 11:14 AM

Quote:

Originally Posted by ROLLGUY

....... If you have access to a dry gas to pressurize the system, you can try different ones to get the right combo. There is no sense charging the system every time, thinking you have it sealed (don't ask me how I know this :-).

Automotive Air Conditioning work should NOT be attempted without access to a dry gas.... Nitrogen and Argon being the usual ' tools'. CO2 is also used by some but I am personally biased against it.
Needing the dry gas is not limited to needing to potentially experiment with gasket type which you are not sure of.
Using a dry gas is recommended by the Mercedes Air Conditioning paper manual... which I have a copy of. It is used to blow the Flush out of the items it is put in to.
THEN once a good pressure test after total reassembly is accomplished the Dry Gas is used as a DRYING TECHNIQUE. This is also the same industry standard used on YOUR HOME AC where which is not able to be wet flushed.
The Dry Gas is put under pressure ( always watching the gauges for indications of leaking ) *****THREE SEPARATE TIMES ***** . This is called a ' triple evacuation ' and is NOT for determining if you have a leak...that is done FIRST... then this is done as part of the DRYING process.

Tech Basics: System Evacuation

Of course these things are discussed in the thread in my signature and in lots of other threads in the archives... they are ALSO INDUSTRY STANDARDS.

Yes, many a field tech skips steps due to greed... but on your own system you have an incentive to follow all the standard steps.. which are based on strictly on the PHYSICS of the situation.

This is not due to ' Guru's wanting to make your life miserable.

This is NOT due to an industry trying to get you to pay them to do the work... again...

IT IS THE PHYSICS OF THE MACHINES AND GASES INVOLVED.

It is like the saying about ' do not mess with Mother Nature'... Do not mess with the PHYSICS of the situation unless you are prepared to risk the cost of living with less than ok cooling.. or possibly having to completely start over due to not following ' the rules' ... an example is not spreading the oil around the system when installing it.. or using the wrong oil...or wrong refrigerant... it is your car... but you HAVE BEEN WARNED.

Working on 20-35 year old MB AC systems IS MISERABLE . Accept that and determine to what extent you want to follow the PHYSICS rules to try to get good cooling from your automobile.

Many people assume that pulling a good vacuum will accomplish all the criteria needed.... as a result of watching AC shops do that... skipping the triple evacuation, the total flush, etc... ask how long their warranty is on the work... usually a year at most...

you can skip lots of important steps on many systems and have the AC work for a year...
but my goal is more than five years because I grew up in an era where our automotive AC's typically worked for 6-10 years with no major work needed... at 6 they might need to be topped off... that was cheap and easy since it did not require any vacuuming ....

and that is another reason to use a straight refrigerant... if you use a ' blend' it will escape in a fashion to where the relative amounts in the blend are no longer what was tested to work well.

The R4 compressor , as mentioned many times, is MORE fragile when it comes to good cleaning of the system since ALL OF ITS LUBRICATION comes from the oil being carried around by the refrigerant.

The Sanden and other of that type have their own ***oil reservoir ***.

This also means that the refrigerant in an R4 system HAS to be good at carrying around that lubrication to expect any long term satisfaction from your efforts and money invested.

http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1443&context=iracc

Good luck,
Greg

Rooster300SD · #21 02-25-2016, 11:15 AM

Leathermang,
Are you still running an R4? On R12?
If you are, how long has it been in and what brand is it?

Thanks,
Jeff

leathermang · #22 02-25-2016, 11:46 AM

Jeff,
I have a 1995 Ford F150, a 2001 Lincoln Towncar and a 1995 Lincoln Continental which all have great working AC's in them.
I started researching AC systems... as you can see in the archives due to my 1981 MB Wagon needing work... I got my 240d a couple of years after giving up on that wagon due to suspension and AC needs... all my mechanic problems are addressed outside... and I have no concrete in the carport...
So I have been gathering up tools and knowledge over the years....Nitrogen tank, digital scales, sniffers, 7 cans R12, gauges , paper MB AC manual , community college HVAC textbook, spare Txvalve, adapters , etc...
Still on the list is the high performance fan from Italy...and a set of crimpers for hydraulic hoses.

Getting the AC working comes after many other things here on the farm.. and the last couple of years were particularly hot... I am 67 and a tad over my ideal gross weight limit... with some back problems thrown in...
So doing the AC on my particular 240d has not happened for several reasons... including hoping a converter kit like Rollguys will be perfected at a cost I can afford.. the Sanden is clearly a great upgrade for our old MB's....
and you can imagine that when and if I attack it...... I can not afford to do it half way.... several people are expecting a video of it.... LOL
I am sorry if this is not what you hoped to hear....

I suggest calling Trey at Carlisle Auto Air in San Antonio for the latest recommendations on AC stuff including the R4. He has talked me out of spending money on things in the past.... so I really trust him...

otto huber · #23 02-25-2016, 12:28 PM

Quote:

Originally Posted by ROLLGUY

Yes, what happened with those manifold sealing washers? I too had a major problem finding the right combo when I did my first R4. If you have access to a dry gas to pressurize the system, you can try different ones to get the right combo. There is no sense charging the system every time, thinking you have it sealed (don't ask me how I know this :-).

I appreciate the helpful feedback that has been offered so far. At the moment, I still don't have the correct washers. The kit most likely to have washers that I can use is listed on the Autozone website, but is not available online or through the local store. This is the kit:A/C Gasket and Seals Mt9518 - Santech (MT9518)

The guy who I recently purchased R12 from worked at a GM dealership for 20 years and has a stock pile of R4 compressor seals. He gave me 3 sets of the AC Delco washers that have green,red and metal washers. Everything else he has appears to be too thin. He is still rummaging through his collection, but I'm not all that optimistic.

The shop that I plan on having a gas charged leak test performed is one of the few shops remaining that is very familiar with these old MB diesels. If I can't find the correct washers before I take it in for the test in a few weeks, I'll just let them figure something out.

leathermang · #24 02-25-2016, 12:37 PM

Are the exact specs for your washers or gaskets available ?
type of material ,
thickness,
hole size,
diameter,
any concentric rings, etc
crush density
????????
Perhaps they are used in some other industry for something else...
or
Perhaps they can be fabricated ?

otto huber · #25 02-25-2016, 12:54 PM

Quote:

Originally Posted by leathermang

Are the exact specs for your washers or gaskets available ?
type of material ,
thickness,
hole size,
diameter,
any concentric rings, etc
crush density
????????
Perhaps they are used in some other industry for something else...
or
Perhaps they can be fabricated ?

I'm having a hard time finding information on this specific Harrison compressor. When you go to an auto parts store they can only base their search on make, model and date of vehicle.

leathermang · #26 02-25-2016, 01:53 PM

Can you do good well lit close up picture of both the compressor and the hose fitting which fits it ?

Also post all the numbers you can find on that Harrison compressor...

and pictures from all angles...

need to be good well lit and as close up as possible...

If something is mechanical and on a car the chances are some fix can be figured out... unless you are dealing with computers... and now when you walk into the parts store pretty much all you have waiting on you are computer readers...

????????
http://www.summitracing.com/parts/fss-24338?seid=srese1&gclid=Cj0KEQiA6bq2BRC6ppf0_83Z1YIBEiQAgPYNvW43bebPcUjPTxIk2lXmD1Du37PUFK7HFm-IWg-f5lIaAjHj8P8HAQ

Call Trey at Carlisle Auto Air in San Antonio and see what he suggests...
and did you check in Hemmings Motor News ? Lots of old vendors who have never seen a computer.... sometimes that is a good thing....

http://www.oreillyauto.com/site/c/detail/MRY0/24338/N1839.oap?ck=Search_N1839_-1_-1&pt=N1839&ppt=C0328

.625 inch thick ?
5/8ths diamter ?
hole size ?

my123ca · #27 02-25-2016, 03:15 PM

My old harrison R4 compressor used a regular oring but the delco R4 i currently have on the car uses seals that have retainers on them. I used the yellow and green sealing washers. The washers came with the R4 compressor.

LNGfish · #28 02-25-2016, 03:21 PM

Glad you got seals and somebody to get you fixed up.

For me it was trial and error and I have a vacuum pump.

I do like mixed refrigerant however but you don't need allot of it.

Use gauges.

LNGfish · #29 02-25-2016, 03:24 PM

That kit at Auto Zone looked like it had the Fattie Flat seal you will need.

leathermang · #30 02-25-2016, 03:41 PM

Quote:

Originally Posted by LNGfish

....I do like mixed refrigerant however but you don't need allot of it.....

This is not a refrigerant thread...but since you said this...
the problems are these... with anything except straight refrigerants like R134 and R12. These have been proven in millions of cars over the last 70 years.

1 . if a mixed refrigerant leaks then you have to replace the entire refrigerant fill because the molecules are of different sizes and your ratio is changed by the leak.. NO just ' topping off' as can be done with R134a or R12.

2. You have to be sure that your refrigerant CAN and DOES do a proper job of carrying whatever compressor oil is needed around the system properly. This is not easy to do and trial and error on this can really be expensive.

3. You need to be sure your mixed refrigerant is LEGAL in the country or state in which you live. The people at the EPA don't have a very developed sense of humor.