Brake booster not working
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Track Day
Joined: Jul 2001
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From: Montreal,CANADA
Brake booster not working
The brake booster of my 1987 carrera does not seem to work. The braking power is find, but pressure required on the brake pedal is way higher than the 88 I just drove.
Could any one tell me where should I look to trouble shoot this problem.
Could any one tell me where should I look to trouble shoot this problem.
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I don't have a 3.2 but, assuming the brakes are like any other cars, I would check the vacuum lines going to the brake booster, the booster itself, and the check valve.
A "normal" check to test the brake booster/vacuum lines is to do the following:
1. Turn the car off and pump the pedal several times. This varies with the type of car and brake system. If the vacuum assist is working properly each time you push the pedal it should get a little stiffer and seem to raise off the floor a little. Try pumping it 10 or 20 times if it doesn't feel like anything is happening, but on most cars it's fairly obvious of the change after about 5 pumps.
2. Step on the brake pedal and start the car. Once the car is started you should feel the pedal feel like it drops down a little.
3. If the car doesn't behave as in steps 1 and 2 above, it's probably a vacuum line leaking or disconnected, a check valve (which prevents vacuum from leaking out of the booster and is in line with vacuum line), or a faulty booster.
If it's not the vacuum, it could be hydraulics. Start the car and push the brake pedal in and hold it in. It should stay solid. If it doesn't then you have a hydraulics problem.
Hope this helped,
Bill Wagner
'91 C4
[ 07-04-2001: Message edited by: Bill Wagner ]
A "normal" check to test the brake booster/vacuum lines is to do the following:
1. Turn the car off and pump the pedal several times. This varies with the type of car and brake system. If the vacuum assist is working properly each time you push the pedal it should get a little stiffer and seem to raise off the floor a little. Try pumping it 10 or 20 times if it doesn't feel like anything is happening, but on most cars it's fairly obvious of the change after about 5 pumps.
2. Step on the brake pedal and start the car. Once the car is started you should feel the pedal feel like it drops down a little.
3. If the car doesn't behave as in steps 1 and 2 above, it's probably a vacuum line leaking or disconnected, a check valve (which prevents vacuum from leaking out of the booster and is in line with vacuum line), or a faulty booster.
If it's not the vacuum, it could be hydraulics. Start the car and push the brake pedal in and hold it in. It should stay solid. If it doesn't then you have a hydraulics problem.
Hope this helped,
Bill Wagner
'91 C4
[ 07-04-2001: Message edited by: Bill Wagner ]
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From: Stuttgart FRG
Hello
The engine has a ventury booster inline to raise the vacuumlevel. The unit sits on the driver side behind the fresh air blower and has some rubberhoses. On the left side is also the connector from the engine hose to the body hose ( white plastic ). Check all for cracks.
Next step is look if you have a bad MBC as the fluid will run inside the booster.
If you go trough the car then put some oil on the brake pedal links.
And check if you have similar brake boosters and MBC in both cars.
Not forget that there are "soft" &"hard" brake pads.
Grüsse
The engine has a ventury booster inline to raise the vacuumlevel. The unit sits on the driver side behind the fresh air blower and has some rubberhoses. On the left side is also the connector from the engine hose to the body hose ( white plastic ). Check all for cracks.
Next step is look if you have a bad MBC as the fluid will run inside the booster.
If you go trough the car then put some oil on the brake pedal links.
And check if you have similar brake boosters and MBC in both cars.
Not forget that there are "soft" &"hard" brake pads.
Grüsse
