Changed out the powerflow regulator and bomb with a used parts from the pick and pull after being unable to budge the bomb with a nylon oil filter strap wrench and breaker bar.
Probably just as well, since the fluid that drained from the system was a mixture of red and yellow oils that didn't like to mix. Not sure if the yellow fluid was brake fluid or a PS fluid.
Went from hard pedal/poor braking-sinking pedal/grabbing brakes with no light on the dash to similar brake action with the light flashing.
Changed to the used bomb I had originally planned to use, and got similar brake action, but no flashing light.
Same switches used throughout.
So the flashing light seems to indicate a bad brake bomb. Is this how the circuit is supposed to work? But only really bad bomb failure? Two out of three weak bombs didn't light it up.
Flashing brake light in 535i instrument cluster means what?
So you have a later model e28 ('86-'88)?
The newer instrument cluster design, which has a single red SI light, has two ways to illuminate the BRAKE indicator:
1. Low brake fluid. When the level sensor switch closes, the light on solid.
2. Low hydraulic pressure. There are two switches. When either closes, the light blinks.
Older instrument clusters had all these sensors wired to the same input, so the light would turn on solid.
On your car, if you look under the hood, you'll see that each of the two hydraulic pressure sensors has a ground wire and a brown & blue sensor wire. Each sensor can be plugged into one of two brown & blue wires. One goes to the blinking input, for the new instrument clusters. The other goes to the regular input, just like the brake fluid level sensor, for the older instrument clusters.
[Edited 12/31/2007 to disable Smilies]
The newer instrument cluster design, which has a single red SI light, has two ways to illuminate the BRAKE indicator:
1. Low brake fluid. When the level sensor switch closes, the light on solid.
2. Low hydraulic pressure. There are two switches. When either closes, the light blinks.
Older instrument clusters had all these sensors wired to the same input, so the light would turn on solid.
On your car, if you look under the hood, you'll see that each of the two hydraulic pressure sensors has a ground wire and a brown & blue sensor wire. Each sensor can be plugged into one of two brown & blue wires. One goes to the blinking input, for the new instrument clusters. The other goes to the regular input, just like the brake fluid level sensor, for the older instrument clusters.
[Edited 12/31/2007 to disable Smilies]
Last edited by RonW on Dec 31, 2007 10:20 PM, edited 1 time in total.
It means that the seal on the MC where the actuator rod goes into the booster is leaking. Unless Brake fluid was mistakenly added to the PS reservoir, thats the only way it could make its way into the system. After re -re- reading your 1st post, the fact that the yellow fluid wasn't mixed would indicate it is prolly brake fluid. PS and ATF being light oils would have mixed together. Have you needed to add brake fluid?
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Steve Haygood
- Posts: 1943
- Joined: Feb 12, 2006
- Location: Thomaston Ga
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[QUOTE="Steve Haygood"]you boys and your used parts (;-0 )(brake booster parts anyway) What if the used reg and accumulator had been contaminated ? I would be for flushing the entire system to make sure....[/QUOTE] LOL, One of the joys of eta ownership is having NOT to deal mit hydro boost system. BTW, most used parts have transplanted with out rejection.
Never had any Vacuum boost issues outside of a rotted hose in ANY vehicle ever