Brake Booster - How do I know if it's bad?
09-04-2010, 10:55 PM
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My Ride: '05 545i SMG, 35% Tint, LED Angel Eyes
I think my brake pedal is beginning to feel a bit weird. I just had my brake fluid flushed a few weeks ago because the brake pedal felt a bit shallow. I could press hard on the peal and reach the bottom of the pedal but felt my car was sliding a bit beyond the line rather than stopping. I just think the booster is got a leak some where and not providing the air pressure needed to push the master cylinder pin in. Any and all input is appreciated. Thanks all.
09-05-2010, 01:57 AM
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My Ride: 2004 bmw 530i
id try pump it a few times while running and hold.turn off engine while leaving your foot on the brake,let it sit and see if the pedal starts to creep to the floor. if it does there culd be a internal leak on your master.
09-05-2010, 05:43 PM
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My Ride: '05 545i SMG, 35% Tint, LED Angel Eyes
If it does have a leak let's say, wouldn't I see some brake fluid spill somewhere? If the pedal creep to the floor , is it just a bad lifter spring on the pedal? I would say there's no more than 1.5 inch travel in the pedal before I hit the bottom.
09-05-2010, 05:55 PM
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It may not be an actual fluid leak - you could have air somehow getting in the system.
09-06-2010, 05:14 AM
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My Ride: Orient blue '05 545i, Sport/Premium Pkg, 6Speed MT, Xenon, Navi, Blue2th, PDC,
I think my brake pedal is beginning to feel a bit weird. I just had my brake fluid flushed a few weeks ago because the brake pedal felt a bit shallow. I could press hard on the peal and reach the bottom of the pedal but felt my car was sliding a bit beyond the line rather than stopping. I just think the booster is got a leak some where and not providing the air pressure needed to push the master cylinder pin in. Any and all input is appreciated. Thanks all.
Good way to check for vacuum leak is:
While the car is stopped press the brake pedal with your left foot while raising the rpms to like 3000 RPM. If the brake pedal is getting softer with higher RPMs that could mean that you have a vacuum leak.
Your problem sounds like you have air in your brake lines. Flush the system again.
See the link
https://5series.net/forums/topic/601...ke+fluid+flush
09-06-2010, 09:31 PM
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My Ride: '05 545i SMG, 35% Tint, LED Angel Eyes
When the break booster is bad you have a completely opposite experience. Brake pedal is very hard and you need to really push hard in order to slow down the car.
Good way to check for vacuum leak is:
While the car is stopped press the brake pedal with your left foot while raising the rpms to like 3000 RPM. If the brake pedal is getting softer with higher RPMs that could mean that you have a vacuum leak.
Your problem sounds like you have air in your brake lines. Flush the system again.
See the link
https://5series.net/forums/topic/601...ke+fluid+flush
Good way to check for vacuum leak is:
While the car is stopped press the brake pedal with your left foot while raising the rpms to like 3000 RPM. If the brake pedal is getting softer with higher RPMs that could mean that you have a vacuum leak.
Your problem sounds like you have air in your brake lines. Flush the system again.
See the link
https://5series.net/forums/topic/601...ke+fluid+flush
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