2 Q's - Brake Booster and Steering rack play issue..

[cliffdunedin 8]

Hey guys,

The e39 failed on a WOF today for brake boost not operating and play at RH Steering rack.

The brake pedal is really hard when engine is off but seems normal when the engine is going, I've googled about the brake booster and thought it might be the water issue as the car was parked up under some Macrocarpas for a few weeks and i washed the car this AM before the WOF but after checking and finding some debris, the brake booster well/enclosure was nice and dry. I haven't scanned it yet but does this sound like a failed booster or master cylinder? Also the DIY's i have seen on youtube are from the e46 and it seems the enclosure around the booster is not able to be removed like the e46, can anyone explain (or link me) how to remove it.

The guy who did the WOF said there's a small amount of play and it should be able to be adjusted, is the adjustment screw (?) on top of the steering rack just need to be tightened slightly?

Thanks heaps team

[Allanw 1071]

Does the brake pedal go hard within seconds of turning off the engine?

It has a check valve, so after the engine is off, you should be able to pump the pedal 3 or 4 times before it goes hard. If the valve is faulty, or the diaphragm is torn, it can go hard by itself, soon after the engine is shut off.

If you shut off the engine, and come back 30 minutes later, and still get 3 or 4 assisted presses, it's normal.

Is this WOF guy clever??? (I'm not joking - there are places I wouldn't trust to WOF my wheel barrow!) Is the play in the rack, or the rackend(balljoint)? The joint certainly can't be adjusted, unless it's loose where it bolts on, but he shouldn't have let you leave if it was that. The rack has an adjustment for the pinion end (driver side), but don't over do it - the amount you turn it is tiny, to take up a fair bit of slack.

[cliffdunedin 8]

Thanks for your reply Allan, I can get maybe 2 presses before the pedal goes hard and it is still stiff when I come back later, so im assuming time for a new booster.

i'll give the rack a tiny amount of adjustment and see how that goes.