W126 SLS high pressure hose from pump repair? - PeachParts Mercedes-Benz Forum

LandYaghtLover · #1 03-07-2012, 10:58 PM

I have read more than a few threads, but none specific to the W126 and the 560.

If I understand right, the high pressure hose comes from the pump and terminates at a metal line.... but where? I have not looked yet, honestly.

What is involved in repair it? Mine is leaking near the pump. In addition to the dang pump leaking. Both I want to take car of now that the weather is warming up. Pump I have figured out, already rebuilt it once. Its this line I dont understand.

I guess what I am looking for is the details. What line size do I need. Recommendation on line pressure rating. It seems I can reuse the fittings on the ends. But how do I remove the line, seems to snake through the engine. Could I just re-route the line to a better location can cut the old line to get it out?

Anyone who has actually done this, I could use some pointers. Photos wold be great if anyone has them!

porkface · #2 03-08-2012, 08:42 AM

i can only mention that the hose NEEDS to be replaced, not repaired unless by a hydraulic hose shop. the system runs approx 1500psi. good luck, chuck.

Hit Man X · #3 03-08-2012, 04:33 PM

It terminates on the frame near the passenger motor mount. It runs behind the water pump among other things. Not sure on the ease of replacement, but it does not appear to be fun.

My high side hose leaks too. They are about $56 new from the dealer last I checked... a competent hydraulic shop should be able to rebuild it for about $30-40.

Remember to use a thin hydraulic oil or the MB stuff. There is a filter in the reservoir too.

LandYaghtLover · #4 03-08-2012, 05:38 PM

Yup. Put a new filter in a while ago. I am using a universal tractor hydraulic fluid. Two reasons. My accumulators are shot, my pump leaks and I just dont care. I go through about a gallon a week now!

But I am betting this fluid is what did in the hose. I actually do not know for sure if the hose is leaking, but I the fluid loss is too great for the pump itself.

For the hose. Yes, I will replace with new. Thats the plan. Read too many stories of people cutting an inch or so off then putting the ends on just to have them blow off. New hose for sure.

As for the dealer hose. That price is pretty cheap, but its for the hose only. No new ends. So really not a savings or any advantage other than some MB stars stamped on.

6G2 hose seems to be the way to go. Or something with a working pressure of at least 1500 (as mentioned above). Those that went with 500psi or less has hoses rupture.

I guess I will find out hard hard it is to snake the old one out, new one in. I may use the "fish tape" method and run a trace cable attached to the old. Then use that cable to pull the new one in. No clue yet until I look at it closer. Some took the crank pulley off. I am NOT doing that!

The plan is to get the proper rebuild kit for the pump, replace the hose then the accumulators. When I do the accumulators I will purge the system of crap fluid and get better stuff.

macdoe · #5 03-09-2012, 03:31 AM

Hello, Try the diesel section. There is the same idea going on in the w123 wagon sls system. There is a diy with pics.

That 6G2 hose size sounds familiar. We repaired the hose and re-used the hose ends on 1 of our wagons awhile back. costed like 10 bucks or something for the hose and got a longer piece than the oem. piece to route it a little bit nicer but not by much. It worked out great. I think the hose we used was a little bit more rigid than the factory piece. There were small bits of plastic in the hose. I can't remember what for, but they may be not in the w126 hose... not sure. The thread is a long one but it tells you how.

I would link you to it but don't know how to paste a link yet.

I am not sure how the hose is routed on the 560... from the pump to the connection on the pass. side framerail (where it is on the wagon too). but maybe you don't need to get fishtapes and such involved. It is actually quite easy on the wagon and very rewarding repair with those re-usable fittings. Cheap too!!
Those kinds of fittings should be used everywhere the pressure constraints would allow??...I like 'em.

macdoe · #6 03-09-2012, 03:40 AM

I use John Deere hydrostatic transmission fluid in mine.(hygarde?) I think I got the idea off here to use. It works.

LandYaghtLover · #7 03-14-2012, 09:53 PM

3/8" hose. Correct? Going to price shop tomorrow. I think the 6 in 6G might mean 3/8. And the "2" being two wire.

I will check out the John Deere stuff unless I can order the real deal.

JamesDean · #8 03-16-2012, 12:08 AM

I'm fairly certain the part you buy from the dealer is the complete hose with couplers on it. The 560SEL had that replaced on it, we ordered the part from XXX and had our local indy do it. It was way too much work for me. LOL.

I'm fairly certain he had to unbolt the motor at some point i vaguely recall this. I'll try to pull up the part number in the EPC when it comes back up.

JamesDean · #9 03-16-2012, 01:27 AM

LandYaghtLover · #10 03-16-2012, 07:36 AM

$79? No thanks. I will get the Gates. $20 for 5 feet and its probably higher rates PSI!

That shows the hose going to the right, driver side, mine goes left. And the motor mount is very much in the way. But the rest looks pretty easy to get to.

LandYaghtLover · #11 03-17-2012, 02:20 PM

Wish me luck! Picked up Gates 6G2 hose. 5 feet of it. $18 was the price. Either today or tomorrow I will be replacing the line. The more I look, the more of a pain it appears. I really think that for removal I may attempt to sever the line at some mid point. I dont feel like spending 30 minutes on just removing the dang thing. Then I can remove and clean the ends without banging them up while pulling the line around the engine parts.

For install I may not put the lower end (by engine mount) field service fitting on at all until I have it snaked through. On that end it seems pretty easy to let it hang down pretty far to work on then just flex it back up and over. The end on the pump has a 90 bend in the hard line. No way to snake that from bottom up.

I would take pics if I were not dealing with hydraulic fluid. But I dont want to risk messing up the shell on my DSLR.

macdoe · #12 03-17-2012, 05:21 PM

Good luck. You seem to be on to something with just cutting the old hose in ease of getting the fittings out. The fittings are the important parts since you won't be needing that rotten old hose anymore. I am not familiar with how your hose is routed, but it sounds like a pain. I wonder if there is an alternative to how you route the new hose, as in.... don't put it back in the same place but rather choose a different and easier approach to the path on the new routing. I know Mercedes has their intricate ways of doing things for engineering purposes but I can't see how routing the high pressure hose would affect anything differently as long as there are no severe bends that would stress the hose or output fittings on the pump.
I have'nt taken a sls pump apart yet....maybe someone that has done so can weigh in on if the pump output fitting can be clocked differently so the output fitting of the pump pointed in a different direction?.....like an alternator.

macdoe · #13 03-17-2012, 05:46 PM

Quote:

Originally Posted by LandYaghtLover

3/8" hose. Correct? Going to price shop tomorrow. I think the 6 in 6G might mean 3/8. And the "2" being two wire.

I will check out the John Deere stuff unless I can order the real deal.

Yes, right on... that is how it was explained to me as well regarding hose size.
The John deere stuff is fairly expensive too. I already had it for the yard tractor so that is why I did it. I would guess the correct fluid would be close to the same price...so if you have to buy it anyways....good plan.man.