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Okay, I'm not sure what exactly this is leaking, but it's not a fast leak. It seems like engine oil leaking from the front lower part of the engine, but I'm not certain. It seems to be coming from a hose in front of the oil pan, as noted in the second picture, but it's very hard to see, as the cradle is in exactly the wrong place to see it. It could be something leaking on the hose.
In the last picture, is some kind of hose with a plug at the end that also seems to be leaking an orange fluid of a very think syrupy texture, of which I am also clueless about.
Anyone with experience or suggestions?
First signs of trouble
What hose is this? (forward of oil pan, center)
And what is this? (lower front of engine, driver's side)
Looks like the ABC pump output there. There are two pipes - 215 / 260 feed the pressure regulator, and 220 vibration damper, which is a U-shaped dead end.
One of these?
Nick
Last edited by Welwynnick; 06-26-2016 at 02:47 PM.
After speaking with someone else, I was reminded of the location of the oil filter. The oil I see now may well be from spillage changing the filter. I'll clean it up and see if it comes back. That still doesn't explain picture #3, though.
What's the unit with #280 #285?
Fresh oil was found on my car on an unit that look similar to that one. It's in front of the engine, driver side. Standing in front of the hood, it's on the left side of the ABC/PS reservoirs. The included picture was taken under the car looking toward the front of the car.
What's the unit with #280 #285?
Fresh oil was found on my car on an unit that look similar to that one. It's in front of the engine, driver side. Standing in front of the hood, it's on the left side of the ABC/PS reservoirs. The included picture was taken under the car looking toward the front of the car.
But now I have to figure out this guy. It appears to be wet almost exclusively on this hose, and a bit on the bit above it(torque converter, I think.)
On the bright side, the transmission electrical connector is bone dry.
I still have no idea what hose that is, and upon further reinspection after cleaning it up and fixing anything that may have leaked there, it seems to be weeping of it's own accord. I'm having a hard time using the diagrams to figure out which one it is. I can't get back under it again without access to a lift. I'll likely have to pay someone else to do it, and don't want to get stranded. Still can't figure where the power steering is leaking either. Little bits seem to get quite a lot of places, somehow.
I have learned in my (long) life that hose weeps are just what they are
You can chase them and replace the hoses, but, in aerospace terms for high pressure hydraulic systems it may be acceptable for weeps.
On my car I do a check every year on the weeps, and them clean them with brake cleaner (I do about 7000 miles/12000km a year.
Regardless of Mercedes' naïve wishful thinking, ABC flexible hoses don't last forever, and weeping hoses are advance warning of catastrophic failure.
In fact, they're so unreliable, I think any flexible hydraulic hoses in the engine compartment should be replaced at least every ten years, and certainly whenever they start weeping.
They can be replaced by new parts from a Mercedes dealer (never from any independent), or alternatively you can get a hydraulics shop to make a repair section with compression fittings that will fit steel ABC pipes.
I understand what can be done, and I intend to have a shop replace it, given it will be months before I am physically capable of doing the job myself. The problem I am having is that I can't figure out which of the hoses in the below diagrams is the one in the picture I have circled above. I need to know which hose to order.
Regardless of Mercedes' naïve wishful thinking, ABC flexible hoses don't last forever, and weeping hoses are advance warning of catastrophic failure.
In fact, they're so unreliable, I think any flexible hydraulic hoses in the engine compartment should be replaced at least every ten years, and certainly whenever they start weeping.
They can be replaced by new parts from a Mercedes dealer (never from any independent), or alternatively you can get a hydraulics shop to make a repair section with compression fittings that will fit steel ABC pipes.
Nick
Nick, I in principle agree with you; in aerospace (3000 psi) terms there are three items for hydraulic hoses:
weeping
seeping
dripping
which are all then specified for their observable condition and rectification.
I just did the 3 ABC hoses under the engine in my CL, the U bend in the front was leaking as was the one in the back you show. That one under the trans attaches to the front hose that goes to the ABC pump over below the passenger side engine mount, then runs all the way to the drivers side, then back to the initial pressure control block/valve block which is on the passenger side. That's why it's hard to see where it goes.
I had to lower the subframe on my car to gain access, and did motor mounts while I was in there. Nick has great info in his many threads to make it more sensible, but it's a decent amount of work no matter how you slice it. FWIW, MB procedures is to pull the engine to change those hoses, and there is no labor time given, it's just left up to the service department to decide what it took, even when the car was in warranty.
From Nick's diagram (post #3), the rear hose is #260, it connects to #215 which goes to the pump on the same bolt as the damper hose #220. MB sells the front two hoses as one part # if you like, (the number around the box, #203), I bought that because it was a tad cheaper than the two hoses separately and came with all the brackets, clamps, bolts, seals, etc for those hoses. That and the #260 part and you have everything from the pump to the first valve block over by the steering rack.
Last edited by ItalianJoe1; 11-29-2016 at 06:18 PM.
If that fails, will the valve block lock or will it keep pumping fluid through the hose? I'm about 98% sure it locks to protect the system, but I want to be 100% sure that it's not going to immediately jettison all the fluid in the system and burn out the pump if I drive it more than a few moments after failure.
Yeah I lost pressure and my car stayed up and drivable, it just gets all floaty and bouncy feeling but it didn't drop. Unless you lose a hose between the front/rear blocks and a strut, it won't sink. As soon as the pressure goes down, the car locks the valves back closed like when you park the car.
I did drive my car about 6 miles from the point of failure to my dealer, where I parked it overnight. In the morning I drove it into my bay and investigated, including removing the belt for further driving around the shop and parking lot. After doing everything, I still had a leak at the front of the pump. I don't know if that was the original point of failure, as my car had a solid leak but was still trailing fluid when I drove it into my lift, or if the line popped and sucking air was enough to damage the front seal. I do know, my pump did not take structural damage, there was absolutely no metal particles in the lines, filter, fluid, etc. So I can't say I caused damage to the pump, but I'm changing it out anyway. I assume my lines let go, as they had been leaking when I got the car, but it's very possible my pump let go and just sprayed fluid all over the lines, it was EVERYWHERE when I got under the car lol.
I was doing about 90-100mph and went over a large dip in the road, and got the momentary red ABC warning because of my failed accumulators, but then it flashed back on a couple times. Within a mile I was getting alternating white and red ABC warnings as the pressure dropped, as I got off the highway and turned around. Stopped and saw fluid pouring out from under the car, but couldn't just leave the car on the side of the highway at 11pm when it was still very drivable. So back to work I went.
In case of a leak, the ABC computer will give you a white/blue warning initially (if the leak is slow) detecting the loss in pressure. If the system pressure drops below 100 bar (e.g., the hose bursts), the computer will shut-off the system, display the red 'ABC drive carefully' warning, and lock the struts in place.
This has happened with me so I speak from experience Please do not get yourself in a situation where the hose bursts and you are stranded in the middle of nowhere! If you do see the red warning while driving, stop immediately and check the level of the struts. If they are all level, and there is sufficient clearance above the wheels, you may drive to safety for the time being. With the red warning, and struts locked in place (verify that none of the struts themselves are leaking), you are good for a bit.
Originally Posted by Jack_88
If that fails, will the valve block lock or will it keep pumping fluid through the hose? I'm about 98% sure it locks to protect the system, but I want to be 100% sure that it's not going to immediately jettison all the fluid in the system and burn out the pump if I drive it more than a few moments after failure.
This has happened with me so I speak from experience Please do not get yourself in a situation where the hose bursts and you are stranded in the middle of nowhere! If you do see the red warning while driving, stop immediately and check the level of the struts. If they are all level, and there is sufficient clearance above the wheels, you may drive to safety for the time being.
Don't forget to check that there is still oil in the ABC oil reservoir.
If you run the engine for any length of time with an empty reservoir, you will destroy the oil pump, and the debris will take out the rest of the system.
Got back from my trip, so if I get stuck anywhere now, it won't be far from home. I'd prefer fixing the problem first. I'll get the hose figured, and get it taken care of.
06-26-2016, 02:25 PM
Still can't figure where the power steering is leaking either. Little bits seem to get quite a lot of places, somehow.
Please do not get yourself in a situation where the hose bursts and you are stranded in the middle of nowhere! If you do see the red warning while driving, stop immediately and check the level of the struts. If they are all level, and there is sufficient clearance above the wheels, you may drive to safety for the time being. With the red warning, and struts locked in place (verify that none of the struts themselves are leaking), you are good for a bit. 
