Beachlean

I know this is a very common issue after doing some research but I could really use some experienced people's help. My dad passed away after he purchased a 2004 cl500 with existing abc issues. Well now my mom needs to get repairs done and I am a state away so can't just be there to replace things daily. Well the issue at hand is the front driver side is very low and doesn't come up when driving or anything. There is an obvious leak as well. She took it to a place called star motors that works on Mercedes and they want to replace the pump after replacing the strut and it not being fixed. If it was the tandem pump wouldn't all four wheels be low? I was thinking it could be the valve block. Any ideas would be appreciated.

tusabes

Could be either the pump or valve block , if they are using the star DAS computer they Should be able to test the system and check the pump

Jack_88

If she hits the button to raise the ride height, does the rest of the car go up or does it stay as it is? If the rest of the car lifts as normal, I'd suspect valve block. If not, then the pump. I'm not 100% on the precise operation of the system, but the hydraulic line between the valve block and strut also comes to mind as a possible source of the problem. Also, it's always possible the repair was not done properly or faulty parts were used. Does it still have a leak?

Beachlean

I hit the button when I first got in it a few weeks ago not knowing anything about the abc system and it did come up. The leak I believe is still there and I was thinking it might be that high pressure return line.

Beachlean

They do use star diagnostics. I spoke to a guy there on her behalf and he wanted to do the strut first and then go from there. He said the strut was very worn (not a surprise being 12 years old) and that if that wasn't the issue they would look around. They don't have a rodeo but pressure didn't seem to be a problem but to the one wheel.

Jack_88

The hydraulic lines are a mixture of metal and rubber, and they are famous for developing leaks over time. I'd ask your mom to hit the button to lift it while it's parked in a dry spot, and move it to see if a fresh puddle appears. Since that corner doesn't raise at all, a fresh puddle would indicate that all the fluid meant to raise it is being dumped out. If there is no sign of a puddle or leakage, we're back to valve block.

She should also be warned that if she runs low on hydraulic fluid, the pump can quickly be damaged driving the car.

Edit: If hitting the lift button doesn't result in any of the car lifting and there is plenty of fluid in the ABC reservoir, then I'd say pump.

biker349

if they can't do a rodeo they don't have the proper system. is the strut leaking? any leaks anywhere? full abc fluid? if car raises with button it's probably the valve block. re-manufactured tandem pumps in the $300-&500 range. also the valve blocks can usually be rebuilt, or bought rebuilt in the $125 if you send in the valve block to $500 if they send you a rebuilt ready to go valve block. it's not a good idea to throw parts at this car unless you absolutely know what's wrong. be advised that arnott sells remanufactured struts for like $600 each.

Beachlean

I don't think they have a rodeo but I could be wrong. It's not a Mercedes dealer but a place called star motors that works on them and has star diagnostic. I am trying to get my mom to test some theories to narrow it down since I am several hours away and in the middle of night shift at work. They already replaced the strut in question and now want the pump done. When I first sat in the car I pushed the abc button on the console and the car did rise just not the one strut. I didn't address it much at the time because she had an old ML that needed a bearing and it turned into bearing, upper and lower control arm, axel, and some new bolts. So you think that the valve block would be the culprit?

Beachlean

There was a leak prior to the strut being replaced but I can't verify if it is still there or not. The levels looked good on the fluid though. Is the valve block known by another name? I am looking on car-part trying to find one but not sure what they have it listed as

biker349

abc valve block. you can check it on e-bay

renault12ts

A rodeo is performed by the STAR system..so they have it.

fireman685

Maybe you can find someone from the forums who is local to your mother to meet her in a public place and check out the car for her. If she were in the North Texas area I would do it. Quite a few different things it could be including the leveling sensor for that shock. When you raise it with the button and then lower it again, does it sink all the way back down immediately. If not, how long does it take? To me it sounds like a valve block issue. I wish you and her luck finding the problem. It's such a terrific suspension system when it's all working like it's supposed to.

Dr Matt

The leak is a very important issue as like others have said, it will ruin the pump if the car goes too low in fluid.

The height problem sounds to me like a possible stuck solenoid in the valve block. Mine is stuck at max height in the right front right now so I am replacing the whole valve block. Not the cheap fix, but I was up to 165 mph in my car just a couple weeks ago. Not taking a chance on replacing my old parts with more used parts and hoping it doesn't happen again.

If the shop has a STAR they should be able to put the car in rodeo, roll, or pitch/yaw and watch how it moves. During those tests you can also watch what the level sensors are doing as well as strut position sensors. If they work on these cars they should know that. I just figured it out how to do this with my SDS myself to my car when it messed up last week. Made diagnosis pretty easy. Of course that assumes it is fixed when I put in the new $1620 valve block, LOL.

Beachlean

Sorry I have been absent from my own post but I got sent out of town on business last minute. The car got fixed at star motors but the prices was ridiculous. It ended up getting a valve block, a strut, a pump, and an abc fluid flush for a grand total of $3800. Fortunately my moms brother stepped up and paid for everything and just told them to do the work so she isn't out that money but still too pricey a fix for suspension. I don't know what all actually needed to be fixed vs what they did replace but I guess it worked out ok.

Jack_88

Yikes, I could see the low fluid taking out the pump, but I doubt both the valve block and strut went out. Sounds their idea of diagnosis was to replace everything that it could be, always the expensive option. A mechanic that might have spent a little time doing simple diagnosis could have been a couple thousand cheaper, unless your Mom was just that unlucky. However, the money is spent, and given how stupid pricey all those parts can be, price sounds about right at least, assuming they used OEM parts.

booesq

All that work for less than $4K? That's actually a bargain. The price of the valve block and pump come to more than the work is incredibly time consuming. ABC ain't cheap, but it's amazing stuff.