Leaking Power Steering Fluid when parked on incline

[concordealex]

'88  535i 5 speed. When I park on an incline (or jack up the front of the car) power steering fluid immediately begins leaking out of the frame area underneath where the driver would sit. This only happens when the front of the car is higher than the rear and has left plenty of nice puddles in my driveway. 

I assume that this is caused by the brake booster. Is it possible for the "bomb" to leak? I have eliminated the reservoir as a possible cause because there are no puddles or signs of leakage in the area around it.

For what it's worth, the bomb, booster, and PS pump are all original to the car and have never been resealed.

Thanks for any help.

[CanadianMiniFan]

In my experience the bomb is far less likely to leak externally, as compared to the booster itself. If you look up with a light from below, there’s a notch at the back of the booster where it meets the firewall. I’m sure you will see a drip from there. It leaks out on an incline because it pools in the frame rail and some of it likely drips out while driving, but more floods out when inclined. A forum member Jay makes an excellent rebuild kit and offers rebuild services for the booster, I forget his forum handle.

[Mike W.]

Agree with the above. Most of the time it's just the big O ring, I forget the dimensions but search, I'm sure it's here somewhere. Occasionally it's one of the other seals and O rings, but not often. Replacing that O ring is not difficult, but be very careful, it's under a lot more spring pressure than you will be expecting and things can go flying when you remove that retaining screw.

[Blue Shadow]

38mm x 3mm o-ring

[Chicagotrader92]

Interestingly, I have this exact same... problem? It happened right after I replaced my steering gearbox a few months ago... It doesn't affect driving, braking, steering, etc, so I've ignored it. My brake booster does not actively leak, although I have seen one drip hanging on the bottom. I assumed at the time that I had overfilled the power steering reservoir and that the frame hole was its escape path. 

Please keep this thread updated on what you do and if it fixes it. I may continue to ignore it if it rquires a brake booster rebuild. 

[Mike W.]

Interestingly, I have this exact same... problem? It happened right after I replaced my steering gearbox a few months ago... It doesn't affect driving, braking, steering, etc, so I've ignored it. My brake booster does not actively leak, although I have seen one drip hanging on the bottom. I assumed at the time that I had overfilled the power steering reservoir and that the frame hole was its escape path. 

Please keep this thread updated on what you do and if it fixes it. I may continue to ignore it if it rquires a brake booster rebuild. 

Steering boxes can leak, I've had a couple that did. Curiously not while driving/running, I could drive 400 miles and come out to a big puddle in the AM and if it had been leaking like that for all 400 miles I'd have been out of fluid! Instead barely low. Not a firm diagnosis, just a could be.

[Chicagotrader92]

Mike
Steering boxes can leak, I've had a couple that did. Curiously not while driving/running, I could drive 400 miles and come out to a big puddle in the AM and if it had been leaking like that for all 400 miles I'd have been out of fluid! Instead barely low. Not a firm diagnosis, just a could be.

My steering gearbox was leaving a big ol' puddle every night. I already replaced it with a used one from eBay, and thankfully, there are no leaks. It was a PITA to get in and out. 

However, if I jack up the front of my car high enough, power steering fluid will leak through the little hole in the frame, exactly as the OP is saying. No leaks unless the front is jacked up about 1ft, then there is a slow drip out of the frame, right below the driver's seat. 

Edit: no leaks or puddles anywhere near the engine bay. If I get under and look up, I do see the smallest amount of PS/ATF fluid on the underside of the booster, but not enough to actually drip from that area. (power steering reservior has remained constant)... Again, unless i jack up the front of the car atleast 9 inches