Removing R4 compressor questions
 

The FSM procedure to remove the R4 says first step is to remove the clutch, then the belt, then the clamps for the hoses then the R4 mounting hardware, the manifold pipe/hoses are to be left in place. I wish it gives a reason.

1. Why does the clutch have to be removed first? Is it a clearance issue?

2. Why is the manifold left on? Is is to prevent oil from spilling? It would seem easier to remove the R4 if the unwieldy manifold is removed and out of the way first.

The clutch & pulley don't need to be removed. There's plenty of room.

I think that the manifold is left on to prevent oil spillage, and later on it's nice to have it removed so you can oil the new compressor. I removed my compressor first, then the manifold, then installed them as a unit. I think it's nice to pull the manifold so you can get everything really clean and install the new sealing washers on the bench, then add oil.

how do you remove the manifold from the hose? Or are you removing the hoses as well?

The FSM calls the metal bit of the manifold + the high pressure hose the "manifold" - so that's all removed as an assembly (There's a few other clamps you need to remove in order from the hose to come out). In my case, I'm not going to be reusing the manifold since I'm switching to a Sanden, however I will be rebuilding some of the suction hoses by cutting off the ferule and crimping in new barrier hose. Hopefully I'll be getting to that this weekend, and I plan to write up a DIY on the job.

Edit: the suction side hose is connected with a fitting that's buried underneath the cruise control actuator. It's not in a very easy place to get tools and leverage for, fortunately mine was not excessively tight

Does the compressor come out the bottom? If so did you have to undo the rubber transmission cooler line?

How about the short hose, from the condenser to the high pressure discharge pipe, mounted with a bracket/ 17 mm nut to block and another bracket to oil pan? Did you have to undo the fitting for that hose and remove it? Or can it stay on and come out with the compressor? The fitting is under the air cleaner by the alternator, space lppks tight to get wrenches on it.

The compressor drops out from the bottom. I don't think we disconnected the trans cooler lines when we pulled it, but we misrouted the high side line when we reinstalled it, so ended up disconnecting the trans cooler lines, and I decided to replace them while we were at it.

The short condenser to high side hose did not have to come out, I don't think. Mine was in rough shape so I replaced it though. You might be able to disconnect the condenser end and take it off as a unit. The bracket is a huge pain to get to. I'm not looking forward to disconnecting it for the second compressor install. I honestly don't remember the exact details, but that was probably one of the more difficult things to access on the entire system. I think I was able to get a wrench on it from under the car. I think the bracket is eliminated with my Sanden kit, and the hose is all one piece to the condenser.

That PITA bracket is held captive by 2 Allen head bolts that go through the oil pan and two 10 mm nuts. Both Allen heads must be removed. The 17 mm nut is removed from the bottom with a socket and ratchet on a short extension. Good that you will be eliminating that stupid contraption with your kit. I may make a custom hose to eliminate mine.

Found this exc. pdf
http://www.peachparts.com/shopforum/attachments/diesel-discussion/129114d1430754844-sanden-retrofit-installation-guide-w123-61x-sanden-ac-compressor-conversion-part-i-ver01-00.pdf

by forum member Mahone Bay on Rollguys Sanden kit which has nice step by step instructions with pics on R4 removal.

Easier to leave the manifold-HP hose in the car. If the car is on ramps, there is plenty of room to install the seal washers after the new R4 is in. But wait until the R4 is back on before oiling it by pouring down the top of the suction tube (disconnect nut up high). However, I agree w/ the plan to replace the HP hose and get rid of the silly run up the R side of the engine and the bracket that bolts to the top of the upper oil pan. I did so, running straight over to the condenser and bending the factory fitting at the condenser down to match. That will free up space and places to trap gunk. You will then find changing the turbo and air cleaner oil drain stub O-rings easy and adjusting the alternator (no EGR also helps a lot). BTW, the AC hose fittings all have circumferential O-rings so don't go crazy tightening the nuts. All you need is enough so they don't unscrew themselves under vibration.

If replacing hose (wise, I did), I recall the suction hose is -12 size and HP hose is -10. Use only "barrier" hose since less leakage and better compatibility w/ non R-12 refrigerants. If you want smaller OD, buy "reduced barrier" size. An AC hose crimper makes factory-looking crimps on new ferrules (I did), but Oeticker step-less ear clamps would look nice too and only require "nail puller" pliers to crimp. I bought all on ebay. You might pay $120 for a used ferrule crimper kit but can sell for $120 when done.

BillGrissom,
Did you reuse any of the original metal tubing? If so, how did you cut the old ferrules off? It looks like some of them may have been brazed to the lines? Did you just cut that end off as flush as possible to the tube?

The problem with just grinding off the sleeves (ferrules), is that the factory fittings are "bead lock", meaning the sleeve is locked into the fitting. If the sleeve is ground or cut off, a new sleeve is only clamping the hose, and not connected to the fitting. This type of fitting has less aggressive barbs than a non-bead lock fitting. I have had experience with the hose coming off because the sleeve is not captured on the fitting (higher pressures with 134a). If you cut off the old hose and sleeve, a new barb can be welded on, and will hold the hose without the sleeve being part of the fitting (coarser barb).

Rollguy,
How much of a problem do you think it is not welding on new fittings on the suction side lines only? Those should be subject to less than 100 psi right?

I am new to beadlock fittings so pardon me if I am not describing it right. Isn't the "beadlock" the "bead" on the male insert where the o-ring seats which also forms a stop against its female mating half? The sleeve or ferrule is for crimping the hose and has nothing to do with the bead.

The Mercedes AC fittings are all beadlock fittings where the sleeve or ferrule is part of the entire fitting and not a replaceable part. If one tries to grind off the Mercedes ferrule and replace with a ferrule with a barb hole in it, it will be a much weaker crimp.

Instead of weld-on crimp ferrules, it'd be better to replace the entire fitting with something like this kit Beadlock A C All Steel Fittings Female Straight 45 90 Degree 6 8 10 9 PC | eBay

This kit is just an example and does not have all the pieces needed.

FYI the reason I'm asking is my welder is terrible (both the welding machine, and the person operating it - me). Would there be a way to braze the ferrule in place over the existing hardline? Or would I possibly be able to buy new beadlock or barbed fitting that would slip over the hardline and allow me to braze it in place?
I'm rebuilding the suction side hoses, fyi - I need to reuse the special fitting at the output side of the condenser, as well as the hardline that runs across the top of the engine bay. The other ends I'll be replacing with new fittings, so that's not a concern.

What size and type is the special fitting you need to connect to? Couldn't you replace the metal suction line across the engine with a hose with fittings?

I thought about that. I'd need to add a low-side fill port at some point in the system. I talked to the rebuilders and they said that the crimp from the crossover tube to the compressor is the most likely to fail due to the extra strain caused by the sharp angle and thicker hose that curves down to the compressor. They offer a new metal line & hose assembly for that area for a very reasonable price, and I'm at the point where I really just don't want any more work to do - so I am going to order that. I'm also going to be cutting the TXV side crimp and end off and having a new slip-over fitting brazed on over it. Fortunately a member of my family is experienced in brazing high pressure systems, so I'll bring him the assembly when I'm in town shortly.

Re-read my post #9. Re-use the outer fittings, just add new hose.

If you do want to procure new fittings, it will take detective work. I think they are an O-ring fitting w/ metric nut and perhaps not even the same tube size as SAE O-ring fittings. That is why Rollguy decided to just braze an old M-B fitting to form his custom hose assemblies. Don't assume that Europe was standardized on fittings in the 1980's. A Wheeler Dealer's episode explored that when trying to source a hose for an Italian sports car in England. They said Lamborghini (?) used an unpredictable mix of various fittings. Ditto for other rare fittings on your M-B.

Do you know what the core of the OE Mercedes hoses are made from? Just want to make sure I use compatible flushing agent on them. For now I plan on re-using all hoses if they pressure test good. I have 2 more hoses to do. So far I have found no leaks, including the compressor, which I had under water and no bubbles!. The first time I tested the compressor was still in the car. I did a input suction and output pressure test by hooking gauges to the inlet and outlet and cranking the engine. I got good vacuum and pressure. I did a pressure and vacuum test with the digital test set and it held vacuum but leaked badly with pressure. I think it may be due to the sad shape of the o-ring on the high side fitting by the alternator (see pic below). There are other o-rings in similar condition. If everything pressure test good, I will just install new o-rings and charge it with R12 and PAO 68 and see how it works out. If it fails, I'll consider barrier hoses then.

http://i31.photobucket.com/albums/c3...810_152624.jpg

I will try to reply tomorrow with some photos, showing the different fittings.

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.

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.:cool::cool:

Beadlock photos
 

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?

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.

The high-pressure hose in one of my 300D appeared to have 2 layers, since the outer layer was spongy and delaminating at the compressor, probably what you termed "heat shrink". It appeared the inner part was just rubber, w/o a dense plastic liner as in "barrier" hose. Similar SAE fittings w/ integral ferrule are termed "Coll-O-crimp" (brand?). I think just a convenience, not to give superior clamping, though probably helps. I am not concerned w/ the hoses slipping off the M-B fittings (OK several years now). Millions of cars in the 60-70's had dealer or after-market AC installed, w/ similar barbed fittings and just a screw hose clamp (special AC ones w/ locating finger). My 65 Newport was like that and I had to cut the hose and aggressively peel it off the barb when I replaced them.

Before tossing your old hoses, cut off the metal ends and save, since those are special, and won't take much space in your garage. You or another guy here will likely need one in the future.

Re other M-B hoses. I recall that on some I rebuilt, their crimped ferrule had depressions that aligned with the ripples on the hose insert. Those had long ripples, not the many little barbs shown in post 23. I re-worked all AC and oil cooler hoses, so forget which. Anyway, I was able to align the crimps in my Master-Cool crimper to match close enough. Your high-pressure power steering hose can be replaced using just box wrenches. It uses "field-replaceable" fittings that screw on the hose. Be glad because I see ~$80 ea prices for those (Parker catalog?). If you can't find my post w/ photos, the trick is that the outer piece is a left-hand thread, so turn it "righty loosy" to unscrew from the hose OD. It is a large "light-bulb" thread. Same fittings on the SLS hoses (300TD guys, their posts informed me). Do buy high-pressure "2-wire" hydraulic hose for that (3000 psi rated, ebay, Tractor Supply), which is superior to what M-B used.

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.

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.

Here's one http://www.ebay.com/itm/261566328165 with #12 fitting, however it does not specify #12 hose so assume it is. Not sure what a 13 mm service port is. I need 1/4 SAE service port since I'll be using R12..

This is if using my old hoses which all tested good do not work out and I still have a slow leak, then I'll make my own barrier hoses and re-route them. I am betting on re-newing all o-rings and schrader valves will fix my slow leak.

Well there you go. That fitting should connected to the manifold, and a male fitting on the other end with a new #12 hose in between looks like it will work for you.
EDIT: you will have to use a 134a charge coupler if using R12.

To flush it, I filled the Harrison R4 that was removed from my 85 300D with 6 oz of mineral oil in addition to whatever PAG oil was in there, which wasn't much when I tried to pour it out, maybe a table spoon came out. Anyway with 6 oz of added oil, it did not hydrolock when I turned the compressor by hand. It just gurgled and spurted out the discharge line.

The other components have all been flushed and dried. I used a mix of carb cleaner and mineral spirit on the condenser and evaporator by cycling it continuously via a solenoid pump. The carb cleaner never touched any AC hoses since it contains some pretty strong solvents not resistant by the hoses, which I believe is Neoprene. To flush the hoses and degrease the condenser and evaporator, I cycled potasium hydroxide through it with the solenoid pump, followed by a few gallons of water, then blowing it out with compressed air, followed by boiling it out with a vacuum pump. We shall see how this works out. I'll have 2 more weeks for it to dry out in this hot weather (I have to order a TXV, dryer and PAO 68 oil) plus I will run the vac pump some more.

The solenoid pump made flushing neat with no mess no spills. This one is doing the evaporator by itself https://www.youtube.com/watch?v=EcP8LJ90mAQ

I have 2 used R4's. The Harrison R4 is from my 85, the Delphi R4 came off a wrecked W123 with working AC. I did the underwater pressure test on both R4's and they both passed. Here's a video of the Delphi R4 underwater test https://www.youtube.com/watch?v=tsAvNn7vOLA

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.