1989 Mercedes 420 sel )Electric hydraulic actuator at fuel distributor has gas leak. Where can I find new seals for it? Or does the unit have to be replaced? Could the be the cause of rough idle and stalling?

I would replace the EHA valve. On mine the case was leaking and I simply replaced it with a new one. From what I've read, new o-rings will rarely fix them. Most of the time it is the actual case that is leaking. A replacement may very well fix your issues but you could have other underlying issues causing them too.

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1989 300CE

hi,hope this helps,nine times out of ten the actual actuator is the part that is leaking gas,that is why they get replaced,do not replace the seals,you can find a good used part with a warranty on ebay,for about $50.00 i did the same thing,when you replace it you will need to readjust your air fuel mixture,this is to recalibrate the new electro hydraulic actuator.good luck,its about $250.00 new

Thanks. I will give it a try

Thanks for the information. Replacing the valve worked. Could you provide any information on adjusting the air/fuel mixture?