does your car have vacuum boosted brakes or hydrallic, if hydro there may be a failing sensor or part in the boosting system, if vacuum i have no idea, our us cars don't have any brake pressure sensors that i've seen
Hi to everyone,
Just went for a little ride in my car and when I was two blocks away from home, got a warning from the OBC, Brake Pressure-See owners manual.
Brakes seems to be normal.
When I reach home, I depress brake pedal several time and the brake pressure message appeared again.
It seems to be linked to number of time I press brake pedal.
Anyone can help me
Kentish
540iA 1994 176000km
does your car have vacuum boosted brakes or hydrallic, if hydro there may be a failing sensor or part in the boosting system, if vacuum i have no idea, our us cars don't have any brake pressure sensors that i've seen
all america wants is cold beer warm cat and a place to take a poop with a door on it
Its vacuum boosted brakes as in all 540i I think. I hope its a sensor failing .When depressing the brake pedal, I can hear pump kicking in to produce the air but after a few seconds I get the message -Brake Pressure from the OBC. May be there is a leak or sensor not working as the brakes are normal.
Kentish
Hi Winfred. I made a mistake, The Brakes are hydro brakes. No vacuum present. I can hear air being pump but just few seconds afterwards, I got the warning from OBC and then it disappear.
Kentish
this could be the begning of a problem, a bad connection or a dieing sensor, i've never worked on a v8 with hydro as our cars have vacuum, the parts should be much the same as the earlyer 6 cylinder cars, there should be a distrubution block with a pressure switch or two and somewear there should be a accumulator aka "bomb" it's about a 4" black metal ball this is what gives the brake pedel it's give, it could be failing, what happens when a bomb fails is it fills up with fluid and the nitrogen leaks out and the brakes get harder and harder as it fills up
all america wants is cold beer warm cat and a place to take a poop with a door on it
I am thinking the same. Someone told me that if this Pressure accumulator goes wrong , the brake pedal will fill harder to depress. I suppose it could be that part. Fortunately its available at the dealer for around $200. I checked all other parts linked to brake system. Apart from some small leak, everthing is okie and no fault code is coming out of the diagnosis plug.
Thanks a lot for the help Winfred.
By the way, i thought that all V8 engine has hydro type brakes and there was not enough space in the engine compartment for the Vaccum servo to be installed. am i correct
Kentish
they stuck a dual servo vacuum unit right behind the left headlight with a linkage going to the firewall on the e32/34 v8s here
Originally Posted by kentish
all america wants is cold beer warm cat and a place to take a poop with a door on it