What does this pipe do ??? 300CE 24v
 

I'm confused
I posted a query a couple of days ago about my power steering hose pressurising and depressurising at 4 second intervals when the engine is running..

Having taken a second, much closer, look the pipe in question it is not a power steering pipe.

However, it does appear to connect to the power steering pump under some kind of shield plate under the fluid reservoir on the side furthest from the engine.
It is solid at this point approx 1/4" dia but as soon as it leaves the pump it becomes a black rubber hose and goes across the front of the engine above the top pulley and then goes back to the bulkhead adjacent to the steering box and then becomes solid again. At this point it then joins two other pipes, one the same size 1/4" and one slightly larger 3/8" coming from the ASD system oil tank the three pipes disappear together down beside the steering box and then go down under the car towards the back of the vehicle.

I still have the fault where this pipe in question is pressurising and the rubber section goes rigid and then it relieves somewhere and relaxes and then repressurises over a 4 second cycle. You can hear this as a thumping noise sat in the car with the engine running. This is how I found it in the first place.

I've looked at pictures in the Haynes manual for the 24 valve engine but this pipe does not exist on their vehicle.

Help in identifying this pipe and fixing the reason why it keeps pressurising and relieving would be much appreciated
Larry:confused:

Yeah, I saw that post, I had no idea what you meant. Now I do!
That's the heater hose! The reason it pulses like that is due to the heater valve opening and closing (pulsing).
Gilly

I'm confused here, if this pipe is a heater line then why does it run underneath the car to the rear of the vehicle alongside the ASD pipes. Also why is the solid section 1/4 inch pipe .
This seems to me to be a pressure line of some sort but for what system ,I do not know.
I suppose my for my next step I will have to put the rear wheels on ramps and depanel the underside to see where it connects at the other end.
Larry

Larry:
Do the hose ends connect to the metal pipes with plain hose clamps, or does the metal ends have those crimped connectors?
Gilly

One thing I forgot to mention in this popsting that was in the previous is that the car is a RH drive UK model therefore the steering box is on the RH side of the car and thats where the pipe in question is.
Larry

Its crimped

Larry:
I'm completely stumped. If you will humor me, check this out one more time, but make sure the climate control is shut off (O button is pushed). It sounds so much like what the heater hose does when the heater valve is pulsing that I'm wondering (no offense) if you are somehow following the routing incorrectly?
Gilly

The routing is from the pump on the LH side of the engine (above A/C compressor) It connects to the LH side of the pump underneath the fluid reservoir. Just clear of the pump it changes from 1/4 dia to rubber and then goes across the front of the engine very close to the top pulleys and then goes to the rear bulkhead changes back to solid and then goes down underneath the car along side the ASD lines to the back of the vehicle behind the under body panels.

Please see the attached pictures.

What does this pipe do??
 

Does no one have any ideas ?
Please see the pictures I have added
Larry

I think I've got it!
 

Larry,
Glad to see I'm not the only one scratching my head over this one!

After doing some detective work in the repair CD, I bet you've got automatic level control. If so, you have a "tandem pump" in which the power steering pump and the level control "oil pressure pump" are driven by a common shaft. Do you have a separate oil reservoir under the hood? If so, you've got level control. That would explain why a pressure line would originate from around the PS pump and head towards the rear of the vehicle.

I don't know what to make of your symptoms, but I did see in the CD-ROM a nice algorithm for checking out the system. It's in section 32-0501 in the Chassis and Body CD.

Thanks for the reply but I dont think I have the auto level control. I dont think that was fitted to the Coupes and it is not in my handbook.
Is it something to do with the ASD system? That is fitted to this car, however I think that uses an electric pump.
Maybe the next step is to depanel the back end underbody and take pictures of where the other end of the pipe connects
Thanks for your efforts
Larry

Is it the hot pipe to the wiper?
 

Coolant is routed to the windshield wiper to melt snow and ice from the base of the arm. Could this be the pipe you are pointing to?

I do have a seperate oil reservoir on this car but I'm pretty sure it for the ASD system


Larry

I agree, the connector & hose looks like the self-levelling hoses in our wagon and 500E.

HOWEVER, it could also be ASD. Check your rear suspension.

If you have struts that have a hose/pipe going to them, then you have self-levelling.

If you have hose/pipe going to the differential, I believe that's ASD.

:-) neil
1988 360TE AMG
1993 500E

I definately have ASD on this vehicle but my understanding was that this was pressurised by an electric pump to lock the differential.
Does the ASD system use perssure from the steering pump ???.
Are there two pumps in one here because the fluid is different for both systems

Larry,
Any progress on figuring this out?

Just wondering...

Steve:
Some of these I have an idea, some I don't. I'll take them one by one
Pic #1 0253.jpg: Looks like what is being pointed to is the brake line for the right front wheel, but I am being confused by the image #5. In image #5, it almost makes it look like the rubber hose is connecting to this hose you are pointing at in #1.
Pic #2 0252.jpg: It almost looks like this hose is connecting to the cylinder head. Looking just by the knuckle of your middle finger, is that a small clamp connecting the hose to the head? I am not familiar with this particular hose on a US version.
Pic #3 0251.jpg: That's the one maybe an inch away from your finger? I'd say that leads to a reservoir, it's definitely not high pressure being a braided hose with a clamp on it.
Pic #4, That's the steel and rubber one I'm seeing, the hose is held on with a clamp. It's easy to see in the picture that it's connected to the steering gear box, if you look in the picture just below the exhaust manifold. It's the return hose from the steering gear box, as returns are low pressure and the hoses can be simply clamped like this. The pressure hose is just below it, inside the shielding tube, the connections on that would be the high pressure fittings, not clamped.
Pic #5 is confusing to me, unsure if this is related to pis #1 or not. You can follow the pipe in Pic #1 and it almost seems like it joins the hose in Pic #5 at a clamp of some sort. I'm thinking more than likely the hose in pic #5 actually goes through the front firewall.
Gilly

Pipe
 

HI Larry

I can't help but think this is for the fully hydralic suspension system that many of the Euro models have/had. You mention it is a right hand drive car so I have to wonder this. Whenever I have run in to this hose pulsing every 4 seconds or so it has been because the leveling valves are adjusted too close to the "filling" position or the pressure control regulator in the system oil tank is bad.

fasthair

The pictures are all of the same pipe unfortunately when posted the order was mixed . Look at the TIP of my finger and view in this order Pic 3,2,6,5,1,and 4
Larry

Thanks for the post fasthair, i see that's your first. Everyone should welcome fasthair to the site, we have emailed back and forth through another site we participate in. He is a independent MB tech in Iowa.
Gilly

Fasthair
Many thanks for your reply. I think you may be right . How do you fix the problem .Thanks
Larry

Are we not talking about the leveling control I mentioned a few posts back? If so, check out the CD ROM as it has an algorithm for evaluating this system. If you don't have the CD, you can get from MB at 1-800-FOR MERC or maybe here at Fastlane.

HI Larry

To check to see if it is this system just look and see if the car has any coil springs for the suspension, sorry I should of asked that before. If it doesn't then this is the system it has for the suspension. To check leveling valves for adjustment disconnect the rods from the valves and raise (fill) the car to it full up postion then lower (empty) the system by moving the control rod untill the car settles down. This is noraml ride height for the car. On the valve there is a 4mm hole and the control rod has the same 4mm hole, they should line up or real close to it. If it is out of adjustment readjust it and see if it fixes the problem. As for checking the pressure regulator it is a bit more involved and requires high pressure guages to check it but like someone said this is on the 124 CD-Rom. Good luck!

fasthair

I disagree on the rear coil springs. I'm fairly confident that all W124's chassis cars, regardless of self-levelling suspension still have their coil-springs in the rear.

My wagon and 500E which BOTH have self-levelling also have rear coil springs

I would check to see if your rear struts have plumbing going to it. If it has plumbing, then you have self-levelling (unless you're running air shocks which I don't think anyone with a W124 would do).

:-) neil
1988 360TE AMG
1993 500E

HI Neil

The system I am talking about is NOT a self leveling system. This system is full hydraulic and has no coil springs front or rear. This system can raise the car above normal ride height with a switch on the dash. This system is similar to the old air ride sytem on the W100 an W109 as far as height control.

Now I would like to clear something up in my last post I just seen that is in error. Because of this system you must set the ready to drive height with the leveling valves. When you lower the car with the leveling valves it will go all the way down. To set height have someone measure the car as it stills on flat ground front and rear. Once the height is to spec center the valve and linkage like I described before. Sorry for the confusion.

fasthair

Wow, I never new of any W124 car that had FULL, on all four corners, hydropneumatic suspension, a la Citroen, 300SEL 6.3, and 600's.

Was that a Euro option only? I've never seen one in the US.

It must ride like an improved 450SEL 6.9

:-) neil

HI Neil

Yes this was a Euro option that never made it here in the states. I forgot about the W116 6.9 having this system and yes it is the very same system. As far as the W124 having the system I am only guessing from Larry's description of his car, that in Europe they have this system on the W124 too. The Europeans get all the fun stuff we never see. Ever seen or drove a W107 3.5 or 4.5 with a manual trans? Talk about a go fast car! Don't know if they ever put it in the 560SL but how much fun would that be?!

fasthair