I am having a problem with the hydraulic system on my 1988 VDP. The car is losing mineral oil very fast. when it leaks, it kind of just comes flooding out. All of the hoses are intact. It seems to happen intermittently and goes along with a clicking noise as it spews mineral oil somewhere on the left passenger side. It has been hard to pinpoint exactly where it is coming from, but going through the forums it looks like the problem is either the Brake Charging Switch or the Low Pressure switch. Is there a way to determine which one, these don’t come very cheap and I would hate to buy the wrong one?

 

I realized I never said Thank you. To preoccupied with the problems. Thanks in advance for any help with this one.

Steve

 

Steven,
I hear your frustration. I also have an '88 VDP, and two years ago it was leaking mineral oil. I looked for the leak everywhere that was suggested, including the low warning switch and accumulator assembly, and still couldn't diagnose where the leak was coming from. I even considered converting the system to the earlier brake booster system.
Eventually through a process of elimination I diagnosed it to the mineral oil green reservoir.....although I had removed it earlier to examine it for leaks and couldn't find any. The reservoir appeared to have no cracks, and the top hoses and connections seemed secure. I therfore concluded that the leak was from the side port where the large hose connects. I replaced the reservoir two years ago with a used one that I found on e-bay motors and haven't had any more leaks.
Check the reservoir connection on the side before delving into replacing more expensive parts. I think I paid about $60.00 US for mine. If the reservoir turns out to be the culprit you may have an extensive search to find one. Good Luck.

 

Thanks for the response. I actually had a problem with the reservoir, the top of it had separated and I replaced it about a week ago, cost me $179 for a used unit on ebay. It was the only one I could find at the time. I originally thought this could have been the problem until the fluid came pouring out. It is clear that it is coming from below, somewhere around the accumulator. I was thinking around one of the two switches I just can't tell which one. I just put more mineral oil in it, but now it is not leaking, so now I have cleaned things up and I can't get it to leak, but weary about driving it so that I don't cause any damage. I will take a better look at the reservoir as you suggested.

Thanks.
Steve

 

Also check your steering rack as that is also part of the system that uses the mineral oil. ( it wont leak when the motor is off but will spray when preasure comes up). there are o rings at the hose connections on the rack as well as seals on the ends where the tie rods come out.

 

I will look at that tonight. I didn't realize that the rack was part of the system. But given that there is mineral oil all over the wheel well this seems possible.

Thanks
Steve

 

Interesting that you say "it's not leaking now" a week after putting in a different reservoir. I remember mine leaked a little for about two weeks after replacing the reservoir. I had thought that replacing the reservoir wasn't the solution, but then it stopped and hasn't leaked since. Wierd eh?

 

Yes a bit, but it is making me think that one of the switches is sticking every time I turn my head. I had to put it on a charger so I have to wait until I can start it and try to get it to leak again.

 

My 88 had the leak at the end of the low pressure switch. Had to replace it.