SL/R230: [FIX] Car losing pressure in one strut with engine off
03-01-2013, 12:49 AM
#1
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SL500
[FIX] Car losing pressure in one strut with engine off
Hi all,
I had the infamous symptom of my SL500 losing pressure in one of the shocks when parked. Sometimes it would be fine, sometimes it would sink on the left front after a day, and sometimes it only took a few hours. According to my MB star manual, the updated "fix" from MB is to replace the hydraulic filter as the first step and then move on to a flush if that does not fix the problem etc. I got a quote for a flush from the dealer for $700 and said to hell with that.
So last weekend I decided I was going to do a filter change and pull out the front axle valve unit and clean it. I also ordered 3 L of Pentosin CHF 11S and filled refilled reservoir to correct level when the job was done.
To begin, I opened the ABC reservoir and sucked all of the fluid out. Closed it up and raised the car to bleed the system. The rest is explained in a short video a mechanic from Autobots Automotive Repairs in Vancouver. Very helpful. I also had the procedure in my STAR manual.
Here are some pics:
The valve unit is located in the left front wheel well
The valve unit removed
Valves removed
Block wasnt too dirty on the inside but a nice solvent bath didnt hurt
Block cleaned in solvent tank
Valve unit reassembled
Unit re-installed
If there is any advice I can give its just this:
-Pay very close attention to valve placement while disassembling and take plenty of pics of the color coded hydraulic lines and electrical connectors in case you forget
-be very careful with the plastic retaining clips on the valve unit. They're brittle
Also, in the video it says 1.5 hrs of labor. Maybe if you have a lift and you've done it before. I spent 6-8 hours on everything but I tend to overdue the cleaning and n\get side tracked easily
So far so good. Have not had a problem with it sinking on any strut in the past few days and have driven it several times. Feels much better.
Also added some LED License plate lights from fleabay. No error codes as advertised and theyre super bright and blue!
Cheers!
I had the infamous symptom of my SL500 losing pressure in one of the shocks when parked. Sometimes it would be fine, sometimes it would sink on the left front after a day, and sometimes it only took a few hours. According to my MB star manual, the updated "fix" from MB is to replace the hydraulic filter as the first step and then move on to a flush if that does not fix the problem etc. I got a quote for a flush from the dealer for $700 and said to hell with that.
So last weekend I decided I was going to do a filter change and pull out the front axle valve unit and clean it. I also ordered 3 L of Pentosin CHF 11S and filled refilled reservoir to correct level when the job was done.
To begin, I opened the ABC reservoir and sucked all of the fluid out. Closed it up and raised the car to bleed the system. The rest is explained in a short video a mechanic from Autobots Automotive Repairs in Vancouver. Very helpful. I also had the procedure in my STAR manual.
Here are some pics:
The valve unit is located in the left front wheel well
The valve unit removed
Valves removed
Block wasnt too dirty on the inside but a nice solvent bath didnt hurt
Block cleaned in solvent tank
Valve unit reassembled
Unit re-installed
If there is any advice I can give its just this:
-Pay very close attention to valve placement while disassembling and take plenty of pics of the color coded hydraulic lines and electrical connectors in case you forget
-be very careful with the plastic retaining clips on the valve unit. They're brittle
Also, in the video it says 1.5 hrs of labor. Maybe if you have a lift and you've done it before. I spent 6-8 hours on everything but I tend to overdue the cleaning and n\get side tracked easily
So far so good. Have not had a problem with it sinking on any strut in the past few days and have driven it several times. Feels much better.
Also added some LED License plate lights from fleabay. No error codes as advertised and theyre super bright and blue!
Cheers!
03-01-2013, 05:05 AM
#2
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2003 SL500, 1998 E320 Wagon
Very good write-up. Looks like it was a messy job. What type of solvent did you use to clean the block? Did you soak the block in the solvent? Did you rodeo the car after you reassembled everything?
03-01-2013, 08:03 AM
#3
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Idk what type of solvent it was off hand. I just went to a friend that had a solvent tank and gave it a good scrub and blew it off with compressed air immediately after. I never did rodeo on the car. I cleared the system using level selection. Didn't take very long either. Before I ever restarted the car I refilled the ABC reservoir. This is very important. Never let the pump run dry! And check it frequently. After bleeding the system the lines can pull quite a bit of fluid.
