Some days it is better to stay in bed! Got my new hand grenades (hydraulic accumulators) and installed. I jacked up driver's side of car and removed the tire. Access was reasonable. I put a clear plastic tube on the proportioning valve bleeder valve in the center rear of car, and opened the valve 1/2 turn - nothing but foam came out for about 20 minutes (turned back into fluid in the collection container - got about 1/2 litre out). I then tightened the bleeder valve. I replaced the driver's side accumulator. put the tire back on and lowered the car. Jacked up the passenger side and removed the rear tire. Changed the accumulator. Re-installed tire and lowered car. Started car and watched the rear end come back up. Re-plenished fluid in front reservoir and took the car for a spin. The ride was great! Got home and as I got out of the car I heard a squeeking on the passenger side rear. Pushing down on the rear bumper caused the squeek only on the down push - no squeek on rebound. The squeek came from the passenger side accumulator - you could actually feel it vibrate as the fluid moved in and out. Took the car for another 25 mile ride - noticed the ride was not as good as the first time. Came back - no more squeek. Now, when the rear bumper is bounced, there was a loud groaning coming from the rear of the car. With someone else bouncing the rear of the car I started looking for the problem. The problem is the actuation lever on the hydraulic proportioning valve in the center of the rear of the car. When the car is bounced the lever moves very stickily - causing a groaning sound as it jumps up and down instead of moving freely. It worked freely before I put the accumulators in and I used Mercedes hydraulic fluid for top up. I really don't want to buy a new valve unless I have to. Any suggestions????

The only think I can think of is that some dirt from somewhere else in the system has gotten stuck in the valve. If you didn't already, you probably should flush out the fluid in the system and replace the system filter (instructions are in the service CD).

If this doesn't solve the problem, the valve can be cleaned and rebuilt if you don't want to replace it. I believe you'll find info here if you do a search (Thomaspin may have posted some info on it).

jlc

__________________
Jeff

'87 560SEL 267K (177K on motor) Blue/Blue
'98 Buick LeSebre 60K (wife's car)
'56 Imperial Sedan 124K
Past Cars:
'67 Dodge Monaco 130K (Sold)
'87 Chrysler 5th Ave 245K and going strong (sold)
'73 Plymouth Satillite 175K (sold)
'96 Chrysler LHS 80K (totaled)

Problem solved. Got lucky. When I disconnected the link from the valve - the valve arm worked freely. Perplexed, I bent the link out of the way and heard the groan! It appears the top pivot on the link was rusted. I cleaned it and re-lubed it and hooked it back up. Problem solved. What appears to have happened was the suspension worked good before I jacked up the rear of the car. When I jacked up the rear of the car the top pivot was forced past it's normal pivot range and partially seized because of the rust. When the car was lowered, the pivot did not pop back to it's previous limited range. Hence the problem. Anyone experiencing a stiff ride may want check the freeness of the top and bottom pivots of the link to make sure they are freely moving as if they seize - reaction time of the valve is compromized. The smooth ride I had first time out after replacing the "hand grenades" is now back! So-o-o-o - anyone changing "hand grenades or jacking up the rear of the car for other work - if you get a new groaning sound (quite loud - sounds like bushings in suspension) - before you delve into it too deep - check the link on the valve - happened to me - could happen to you. Thanks jcantor for your tip - I thought I had kept the lines clean when I disconnected them - but a good tip for others to maintain cleanliness when you have any hydraulic system. Hope this post is of help to others
Thanks again!!:p :p :p :p

Dear Forum,

I am trying to replace one leaking rear shock and two air cell accumulators on my 91 560SEL. I have done many other repairs but this the first for this type work. Do you simply replace the bad parts with new? How do you bleed the system and what is the correct sequence of this maintenance work?

I do appreciate any suggestion and expertise that you can provide.

Best regards,

Lucciani