ADS 1 1990 500SL

[Coli]

Ok, got car up with back wheels on blocks.

There is a small diameter cylinder 13mm ish and coming out of each end there is a thinner rod with a balljoint to allow a flexible connection at right angles via a 6mm threaded peg secured by a 10mm head nut. One end is connected to the body the other to a lever on a valve body. Presume this is operated hydraulically via two thin tubes going into the side of it to vary the length and open/close the valve which it is attached to.

One end was not tightly secured so someone has been at this before.

I removed this from the valve control arm and the car lifted and dropped when the arm was moved up or down so that side of the system is working.

It looks like the adjusting mechanism cylinder described above is not being activated or is seized,

The tubes that ran from that went under the fuel pump cover I could not see them following the fuel lines along the bottom of the car, maybe they run through the car, ran out of time to investigate further and not really sure where next to go.

Cheers

 

[Richard Moakes]

Ok, got car up with back wheels on blocks.

There is a small diameter cylinder 13mm ish and coming out of each end there is a thinner rod with a balljoint to allow a flexible connection at right angles via a 6mm threaded peg secured by a 10mm head nut. One end is connected to the body the other to a lever on a valve body. Presume this is operated hydraulically via two thin tubes going into the side of it to vary the length and open/close the valve which it is attached to.

One end was not tightly secured so someone has been at this before.

I removed this from the valve control arm and the car lifted and dropped when the arm was moved up or down so that side of the system is working.

It looks like the adjusting mechanism cylinder described above is not being activated or is seized,

The tubes that ran from that went under the fuel pump cover I could not see them following the fuel lines along the bottom of the car, maybe they run through the car, ran out of time to investigate further and not really sure where next to go.

Cheers

Those thinner tubes convert from flexible to fixed and run all the way back to the main ADS valve at the front offside.

I suspect your diagnosis is correct, and you will need to find one of those adjuster cylinders from a 600SL that’s being broken etc.

 

[Coli]

This adjuster must be stuck in the default position which is sport so quite hard.

This is with the cylinder rods fully extended as the car rises when lifting the control lever which the cylinder does by the rods retracting, I may as well have a go compressing manually see if it frees off.

Had you tried obtaining any of these ADS parts from mercedes, the steering angle sensor was available.

Sourcing second hand will depend what the person selling it decides to call it, I got the SAS by chance searching the part number as it was listed as “Steering contact ring”

Thanks again.

 

[Coli]

Further to above, removed the adjusting cylinder. One end had an 8mm piston rod coming out this appears to function can be pulled in and out about 6mm.The other end has a larger diameter piston which can be rotated, freely but it is tight, but it will not move in or out, it appears to be out about 12mm.

There is a large range of adjustment on the thinner rod by screwing it in out of the piston, this has obviously been messed with in the past, any info on setting the length of this would be useful.

The two hydraulic lines have fluid, one drips very slowly, this is to the thin piston, the other has more pressure but appears aerated, this was with engine running at tickover.

Cheers

 

[Coli]

Fixed.

Found a photo on another forum that showed the level control piston assembly can be disassembled, the reason the larger piston was stuck out was that the o ring to hold the pressure above it had worn and allowed fluid past as there was nowhere for this to go it hydraulic locked the piston out. Luckily I had an o ring of the correct size so cleaned everything replaced o ring and re-assembled everything and it works. There may be more to come I only replaced the moving piston sealing ring as the one in the body was not showing signs of leaking as fluid would have shown externally and did not want to chance damaging it on removal to check size.

Bit of trial and error still required to get a correct final length to give the right height but other than that so far so good.



Cheers

 

[Richard Moakes]

Fixed.

Found a photo on another forum that showed the level control piston assembly can be disassembled, the reason the larger piston was stuck out was that the o ring to hold the pressure above it had worn and allowed fluid past as there was nowhere for this to go it hydraulic locked the piston out. Luckily I had an o ring of the correct size so cleaned everything replaced o ring and re-assembled everything and it works. There may be more to come I only replaced the moving piston sealing ring as the one in the body was not showing signs of leaking as fluid would have shown externally and did not want to chance damaging it on removal to check size.

Bit of trial and error still required to get a correct final length to give the right height but other than that so far so good.



Cheers

Nicely done Sir, that’s a pretty advanced repair

 

[Coli]

Thanks.

Worth persevering it drives like a different car.