2003 SL500, purchased a year ago with 98k miles. (I had previously owned a R129, 2000 model for six years). Everything has really worked well on the car and now I’m at 107k miles and have enjoyed every mile, But,

It all began about a month ago; I noticed a spot of hydraulic fluid on the garage floor behind the driver’s side front tire. Took it to mechanic and he found leak at the left front leveling block (whatever that is). He rebuilt and no more leaks and the ride was perfect. As a follow up I flushed the fluid and changed the filter the same week and all was good, the ride was perfect; Ahhh, but there is more.

A few days ago as I’m backing out of the garage I heard a loud pop and then a whooshing sound. I stopped the car and found a lot of fluid at the left front tire. I jacked up the car, removed tire and inner fender and discovered that the “car killer” hose had ruptured. My mechanic said the motor would need to be removed to replace the entire hydraulic line. Well crap!

A little google and YouTube and I found a way to cut the metal part of the line, remove remaining line from front block, went to hydraulic hose manufacturer and had a new hose crimped in place, then used a 5000# stainless steel compression fitting to repair my cut line. Installed new line, topped off fluid and here’s where the mystery started.

When I backed the car out of the garage it immediately lowered on all four corners. The ABS white warning came on, then as I drove it raised the car, but all the way up. I looked like a jacked up F150 ready to go off-roading. When I can to a stop light and waited a few minutes when I released the brake the car lowered on all four corners, as I drove it went all the way up, next stop, all the way down.

After a drive last night I parked in the garage and all four were up and it’s stayed that way all night.

So, all knowing super mechanics, what’s my next step?

Maybe it’s not all bad; my wife likes the high profile, “it’s much easier to get into when it’s higher”.

 

Did you bleed the system after refilling? If not, try raising suspension to max, then drop it to minimum, repeatedly for a few cycles. (Say 10). Then check ABC fluid level in the reservoir.

 

Yes, I cycled it up and down several times, but I noticed that only the front raises and lowers, the rear stays down. thanks for the suggestion.

 

When ABC performs erratically it's difficult to tell whether it is a consequence of faulty inputs to the controller or outputs. You need Star Diagnosis, a Foxwell NT510, or something similar to troubleshoot.

With Star Diagnosis I would connect with the ABC controller and view the chassis level and strut position sensor values and determine their plausibillity. Then I might take manual control of each of the four ABC struts and see if each faithfully responds to my commands to raise and lower the chassis.

Star Diagnosis can be had for as little as $200. The Foxwell duplicates the essential diagnostic functions of Star Diagnosis but runs considerably slower and has a much smaller display screen.