Removing R4 compressor questions - PeachParts Mercedes-Benz Forum

Demothen · #1 08-12-2016, 09:45 AM

Funola,
That high side hose by the alternator was in bad shape on my car, I think due to a leaky oil cap/oil breather. You might try to dig your fingers into it and make sure it's solid. If you need a new one, I think I'll have one that won't be getting used now that I'm switching to a Sanden. I could sell it to you cheap if you want it.

funola · #2 08-12-2016, 09:56 AM

My hose looks ok and passed the underwater and digital pressure gauge test. I even cut away the thick heat shrink layer so I can see bubbles more readily... there were none. Here's a video of the test https://www.youtube.com/watch?v=SsROH43eLxg

PM me the price of the hose. I may consider it if the price is right.

ROLLGUY · #3 08-12-2016, 11:11 AM

Here are some photos of beadlock fittings and one of a factory MB sleeve cut and ground off.
The first photo shows the sleeve mostly cut off to show how it is captured by the "bead" (groove). Without the sleeve being part of the fitting, the hose and crimped sleeve would come off under pressure because of the almost non-existent barbs.

Photo 2 shows the fitting without the sleeve

Photo 3 shows a weld-on barb brazed to a fitting

Photo 4 shows an MB pipe with the sleeve ground off, and a fitting welded on. If a hose was crimped on the end after the factory hose and sleeve were removed, the hose and sleeve would come off under pressure.

I don't suggest using factory barbs to attach new hoses to. A barb made for that purpose should be welded on so standard hose and sleeves can be used. These have more aggressive barbs on them to hold the hose, without needing the sleeve to be a part of the fitting.

funola · #4 08-12-2016, 12:03 PM

Quote:

Originally Posted by ROLLGUY

Here are some photos of beadlock fittings and one of a factory MB sleeve cut and ground off.
The first photo shows the sleeve mostly cut off to show how it is captured by the "bead" (groove). Without the sleeve being part of the fitting, the hose and crimped sleeve would come off under pressure because of the almost non-existent barbs.

Photo 2 shows the fitting without the sleeve

Photo 3 shows a weld-on barb brazed to a fitting

Photo 4 shows an MB pipe with the sleeve ground off, and a fitting welded on. If a hose was crimped on the end after the factory hose and sleeve were removed, the hose and sleeve would come off under pressure.

I don't suggest using factory barbs to attach new hoses to. A barb made for that purpose should be welded on so standard hose and sleeves can be used. These have more aggressive barbs on them to hold the hose, without needing the sleeve to be a part of the fitting.

Questions:

1. Photo 3 does not have a beadlock type ferrule. Why didn't you use a weld-on beadlock type?

2. In photo 4, what kind of fitting was welded on to the pipe? What kind of pipe is that and why was that work necessary?

ROLLGUY · #5 08-12-2016, 12:11 PM

Quote:

Originally Posted by funola

Questions:

1. Photo 3 does not have a beadlock type ferrule. Why didn't you use a weld-on beadlock type?

2. In photo 4, what kind of fitting was welded on to the pipe? What kind of pipe is that and why was that work necessary?

The fitting in photo 3 is a custom fitting that has a #8 barb brazed to a #10 fitting (used in my Sanden hose kits).
The fitting welded on the pipe is done on all the 123 Sanden retrofits, so a hose can be connected from that pipe (low side hard pipe going on top of a 616 or 617 in a 123) to the compressor. Check out the PDF installation guide link in my signature.

funola · #6 08-13-2016, 09:08 AM

Quote:

Originally Posted by ROLLGUY

.......
The fitting welded on the pipe is done on all the 123 Sanden retrofits, so a hose can be connected from that pipe (low side hard pipe going on top of a 616 or 617 in a 123) to the compressor. Check out the PDF installation guide link in my signature.

Why can't that low side pipe be eliminated with a -12 hose and -12 fittings with a service port to go between the R4 compressor manifold pipe and the suction hose from the TXV?

Demothen · #7 08-13-2016, 09:44 AM

Quote:

Originally Posted by funola

Why can't that low side pipe be eliminated with a -12 hose and -12 fittings with a service port to go between the R4 compressor manifold pipe and the suction hose from the TXV?

I havent tried, but it is real tight routing where it dips under the cruise control and behind the power steering pump. Just to get the pipe out I had to pull the cruise control and disconnect the vacuum pump.
Fun tip: the vacuum pump can be capped using a clean port cap for a receiver drier, if you have out laying around. I have taken to saving all of the caps I get with various fittings, they seem to work in other fittings somewhat frequently.

ROLLGUY · #8 08-13-2016, 10:24 AM

Quote:

Originally Posted by funola

Why can't that low side pipe be eliminated with a -12 hose and -12 fittings with a service port to go between the R4 compressor manifold pipe and the suction hose from the TXV?

I doubt an inline service port is available in #12, but if so, I can't see any reason why the pipe couldn't be eliminated, and use rubber hose all the way for R4 installations.

BillGrissom · #9 08-15-2016, 03:41 PM

Quote:

Originally Posted by funola

Why can't that low side pipe be eliminated with a -12 hose and -12 fittings with a service port to go between the R4 compressor manifold pipe and the suction hose from the TXV?

Why? I just replaced the short -12 hose on the end of that tube. The tube is lighter than hose, bolts well to the engine, and has the R-12 service port you need. It isn't hard to cut off the collar-crimps. I just used a hacksaw at the end, air cut-off wheel axially, and pried it off w/ screwdriver's and pliers.