jimbo11901

Does anyone have a Hydaulic Schematic of the high pressure Power Steering/ Power Brakes system for a 1990 Coupe Quattro? I have a leak occurring at the screwed in plug on the top of the hydraulic pump. I removed the plug and found that the o-ring gasket was blown. I replaced the o-ring and it blew again right away. Tried a harder ring, and that blew too.

Perhaps the "dump valve" (the hydraulic valve that determines system pressure) is somehow malfunctioning. I was wondering where that valve might be, and was hoping that a hydraulic schematic might shed some light.

Is is part of the Hyrdraulic Pump? Is the spring and plunger under that screwed in plug part of it?

Any info regarding this would be great. I would prefer not to replace the whole pump.

Also - I had this pump replaced about a year and half ago, after the original one froze and broke the shaft. I had a similar leak initially after the new pump was put in, which my serviceman replaced under warranty. It's been good since then, up until 3 days ago.

Jim

Regenmeister

YGM

jimbo11901

Thanks - that's a good start. I'm guessing mine is the single pump (on the bottom of the diagram)?

virtuapete

a few thoughts in my head regarding the pressure of the system. My bomb just sprung a leak not long ago and the thing is fairly new, plus the weep at that plug. So I might need the same info you might have gotten already? What have ya found?