Roadtrip breakdown: SLS advice needed - PeachParts Mercedes-Benz Forum

kerry · #1 06-25-2007, 07:46 PM

Here I am in a hotel in Blanding, Utah. Just did a raft trip on the San Juan river and as I was driving from the take out I started smelling hydraulic fluid. Stopped and there was a leak, apparently from the high pressure hose on the SLS--rubber hose running from pump across front of engine and up passenger side for a few feet. Looks like it is leaking just above the water pump. At least that is where it was dripping. There was fluid everywhere in the engine compartment. Added some fluid and got to Blanding. Added more fluid, (power steering fluid this time since I was out of the right stuff) and it blew it all right out. Plan at the moment is to have the mechanic pull the hose in the am, take it to Napa and have them make up a new hose. Anyone see any problems with this plan. Should NAPA be able to attach new high pressure hose to the old fittings? Any foreseeable problems?

In addition, it's possible the pump ran dry for a while. Will this have damaged the pump or can it take some dry running?
I'm pretty sure the system is self-bleeding so if the pump is ok and the hose is replaced, it should bleed and pump itself up, I think. Right now, it's sitting right at the bottom. I was carrying a heavy load and pulling a trailer so it's almost totally dependent on the SLS to sit at a driveable level.

GREASY_BEAST · #2 06-25-2007, 07:55 PM

I've had my fair share of sls problems with my 1984 300TD. Yes, the system is self-bleeding, and I believe the pump can take some (limited) dry running, but I would minimize that at all costs because it would be one expensive bugger to replace. The exact thing you described happened to me, luckily while I was at home, but I discovered that the fittings are re-useable... that is, they screw apart, and you ram the inner part in a new hose, and screw the outer part down over it. If you get a length of hose that seems to fit, and they have a vice and a pipe wrench at NAPA, you should be able to do it. As I recall it took a lot of sweating, swearing, heaving, and grunting.

EDIT: you should be fine running PS fluid until you get home.

groovinola · #3 06-25-2007, 11:04 PM

kerry,

sorry to hear or your recent misfortune. a similar scenario just happened to me although i was lucky enough to be in my driveway when the hoses (thats right two in a row) blew.

to the best of my knowledge this is what steps you need to take to get going again. please anyone add or question/correct anything you might have a different knowledge of or experience with.

First things first. removing this hose is easy. the first thing to do is to get under the back end and undo the bleeder screw on the front of the valve to realease any pressure that still might exist, although it doesn't sound like that is much of an issue for you right now. next remove the air filter and housing to get at the connection for the pressure hose. you'll need a 12mm (line wrench if possible) and a 17mm to undo the connection to the supply line. You then use the 17mm on the banjo bolt attached to the pump. you can get to it with out removing the radiator hose above it but it is easier to access moving that hose. be careful not to lose or drop the copper washers off the banjo bolt. there are two, one on each side of the banjo fitting. now you should be able to remove the hose out of the car with no problem.

once you have the hose in hand clamp down or use vice grips on the round metal end of the hose and remove the fittings. the banjo fitting takes a 14mm and the other end a 17mm. save the fittings and try to get a new hose that matches the one you blew out. i think NAPA can probably do it or would know someone who can. when you have the new hose just work backwards and reattach everything up front.

when the front end is back intact and the supply tank filled (napa should also sell hyraulic fluid which should be ok to get you home or somewhere you can get the good/expensive stuff) you need to get under the rear end again with the wheels or trailing arms supported (either on the ground, on ramps or on jack stands under the trailing arms. undo the rod that runs from the control arm on the sls valve to the torsion bar and center the arm. make sure the bleeder screw is tight. start the car. with the car running get under the back and loosen the bleeder screw ever so slightly until a stream of fluid is coming out (this will also let you know your pump is still working). this can get a little messy and make sure you have some eye protection. once you have a stream tighten bleeder screw and raise lever upwards into "fill" position. at this point the car should raise up. get out from underneath and measure the distance on both sides from the center of your wheels to the top of the wheel well. also you will probably have to add more fluid as the supply tank will have circulated into the system. now go back under the car and gently/slowly lower the contol arm until the rear end sits 12.75" from the center of the star on the hub to the top of the crescent of the wheel well. keep the car fully loaded when you set this height. reattach the rod to the height where the control arm sits and check for any leaks. top off the fluid level and you should be good to go.

as for the pump and dry running you should be ok. i read somewhere in the last couple of days, i think on the service disk, that getting air into the system will compromise the pump and that a certain part of the pump (the driver?) if not the whole thing should be removed if running the system dry for any length of time. hopefully you didn't run it long enough to do any damage. if you get a flow out of the bleeder valve with everything reattached and the car running you should be ok. good luck and keep us posted on the outcome.

peace,
woody

vstech · #4 06-26-2007, 08:41 AM

you want him to get under the car while it is fully loaded and move the leveler rod? are you crazy? the bumper is known to hit the ground while loaded, this sounds VERY DANGEROUS!@!!! be cautious! do not get yourself killed with this car!

groovinola · #5 06-26-2007, 09:20 AM

Quote:

Originally Posted by vstech

you want him to get under the car while it is fully loaded and move the leveler rod? are you crazy? the bumper is known to hit the ground while loaded, this sounds VERY DANGEROUS!@!!! be cautious! do not get yourself killed with this car!

if the car is safely supported on jackstands or ramps, which i recommended in my post, there shouldn't be a safety issue being under the car. if the car is on the ground and loaded and the system is bled out it isn't going any lower and there is probably no way of getting under it to begin with however i do agree to being very careful anytime you are under a car.

in answer to your question, no i'm not crazy, i'm just trying to help someone out and made the assumption (which i will try not to do in the future) that someone with over 5,000 posts on here probably has enough common sense to know what is and isn't safe when under his car. constructive criticism is one thing....

vstech · #6 06-26-2007, 09:28 AM

sorry about the dig, just trying to put the warning out there for others that may not have 5000 posts, trying to repair their SLS from reading the responses.
we (me included) have to remember, that these answers last for a long time, and many many many people read them, and use the info. so warnings are really important.

kerry · #7 06-26-2007, 09:45 AM

Thanks for all the good advice. I wasn't about to get underneath. I've got an appointment at 8am at a shop. Normally I'd DIY but without all my tools and no jackstands or ramps, I'll have someone else do it.
Which screw is the bleeder screw?
I don't know how long it ran dry if it did. I added some more fluid last night and it started spraying out the hose so at least the pump is producing some pressure. The car did not rise up so I assume the leak is bad enough that it is not building enough pressure to push it up.

JimmyL · #8 06-26-2007, 10:11 AM

Well, maybe my high pressure hoses have been different, but both of my wagons have blown out this hose. I do not remember the ends being removable at all. I took both to a hydraulic hose shop. They cut the ends off and braised them to new hoses. Around $50 or $60 bucks.
No need to do anything with the bleeder screw, it will self bleed.
Dang, sorry it happened out on the road. I would recommend that folks replace this hose when they get their wagons if no sign of previous replacement. The originals seem like they are of about the age to blast off......

kerry · #9 06-26-2007, 10:38 AM

Uh oh. I hope they are removable. That's what I told the shop. I did see a nut at the end of the round part of the fitting. I can't imagine why the nut would be there unless the fitting can be unscrewed. The good news is that when I drove it to the shop this morning, it rose up, no viagra necessary. Must be when it's cold the hole is tight enough to allow enough pressure for it to work. The pump must not be damaged.

groovinola · #10 06-26-2007, 11:07 AM

the banjo fitting at the pump and the pressure connector fitting are definately removable unless your hose is somehow different than the five I have. they screw into the round metal ends of the hose itself. these round metal ends are not removable and need to be the right size when the new hose is made to accept the banjo fitting and the pc fitting. good luck

ps. just in case, the bleeder screw is just above the leveling arm and usually has a rubber nipple covering the end of it which is where the fluid escapes from when loosened. it takes an 11mm. either way you will want to bleed your system and replace the fluid with febi (or comparable) when you get home.

csp97 · #11 06-26-2007, 11:26 AM

I wouldn't be too worried about your pump. I bought my 300TD a year ago with no fluid in the SLS resevoir. I had no previous experience with mercedes diesels. The car had no owners manual and it took awhile for me to find this site so I had no idea the SLS even existed. My pump ran for several months, maybe 5,000 miles, and who knows how long before that with no fluid. I filled it up and it works fine except for a small leak in the same line you're talking about.

kerry · #12 06-26-2007, 12:48 PM

Here's the update. They removed the hose and took it to NAPA. Apparently the fittings require Aeroquip hose and none is available in Blanding. So the mechanic cut off a section of the existing hose planning to bypass the leak and reuse it. Unfortunately, he did not cut back far enough and after spending about an hour reattaching the fitting, I returned to tell him the leak was still in the shortened hose. So now he's cutting off more hose, reattaching the fitting, and reinstalling. Good thing the hose is extra long. The fitting is quite difficult to reattach if the exasperation level of the mechanic is any indication. He showed me the ID of the hose and how far it has to expand to accept the fitting. It must take some effort. I imagine hydraulic shops use some kind of machine to attach the fitting.

This is not the best solution but it should get us home if the rest of the line can hold up. I know an Aeroquip shop in Denver so I'll take it there when we get home.
That's good news about running the pump dry that long. I'm not in a position to drive home running it dry because I'm carrying about 1900lbs of rafting gear, people, and trailer so without the SLS the back is just inches off the ground. Doesn't seem like a safe driving configuration.

arew264 · #13 06-26-2007, 01:53 PM

Oh man that stinks.

This is like "the dark side of the wagon"(

)

groovinola · #14 06-26-2007, 02:01 PM

Just an fyi from the infamous pdf file 40-310 (not available on the 123 service manual library disc). "t-sedans standard version [includes 123.193] with normal additional load (permissible rear axle load 1150/1155 kg or 1195/1200 kg) = [2535/2546 lbs or 2634/2645].

depending on the tongue weight of your trailer (plus your 1900 lbs) you are pushing it. i always wondered about towing on the back of my wagon. i was told it was very taxing on the transmission. good luck getting home and safe travels.

peace,
woody

groovinola · #15 06-26-2007, 02:05 PM

kerry,

one more thing. if you have problems on the way home there is an awesome mb mechanic in glenwood springs. his name is randy and the shop phone # is 970 945-0869