Brake booster '91
Thread Starter
Melting Slicks
Joined: Dec 2008
Posts: 2,772
Likes: 64
From: Mystic CT
Brake booster '91
Should the brake booster hold a vacuum and is it possible to use a hand operated 'mighty vac' to pump it down? I need to solve the bad brakes game I am playing with this car. If the booster has to come out I will do the cluster at the same time as most of the same parts need to be removed. Not sure how to fix the oil temp gauge yet as the dealer put a new sender in and said wiring was just fine though certain they did not trace back to the cluster as the bill wildly too low for that. I am wondering if the same resistor network runs some of the other analog gauges that runs the tach and one chip fixes all. This has been a zero miles on it summer and not very pleased to be honest. No time to work on it and not safe to drive in my mind. The body needs a good waxing and the bumpers fresh clear coat as paint looks good but clear faded so worth a try in my mind on the bumpers.
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Joined: Jul 2016
Posts: 79
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From: milwaukee wi
yes, it should hold vacuum... so a mighty vac should work fine.. if it doesnt hold pressure the diaphram is shot..
the booster is really completely seperate from your dash.. its literally 2 bolts to get it off. my new one comes tomorrow... and all you have to take off is the lower dash cover..
looks super easy compared to what i was expecting.
the booster is really completely seperate from your dash.. its literally 2 bolts to get it off. my new one comes tomorrow... and all you have to take off is the lower dash cover..
looks super easy compared to what i was expecting.
Thread Starter
Melting Slicks
Joined: Dec 2008
Posts: 2,772
Likes: 64
From: Mystic CT
I have done it once and I think mine is 4 bolts with a miserable reinforcing plate poorly drilled and does not want to line up. Once the knee bolster is down and booster out to be fixed only a couple of bolts to lower steering column and a few screws to pull cluster.
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From: Anaheim CA
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From: Lansing MI
Safety Car
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From: Mission Viejo CA
Here's a better test:
1. Start the engine.
2. Step on the brakes. Note where the brake pedal stops. Release pedal.
3. Shut off the engine. Wait about 10 sec. Step on the brake pedal. It should depress to about the same position as with the engine running.
4. Depress the pedal several times. You should get at least two additional strokes before the pedal gets higher and harder due to no more residual vacuum.
If the pedal feel is the same at the beginning of this procedure as at the end, you have a bad booster. If the booster won't meet the two additional stokes after the engine is shut off, you have a bad check valve on the vacuum line or a bad booster.
1. Start the engine.
2. Step on the brakes. Note where the brake pedal stops. Release pedal.
3. Shut off the engine. Wait about 10 sec. Step on the brake pedal. It should depress to about the same position as with the engine running.
4. Depress the pedal several times. You should get at least two additional strokes before the pedal gets higher and harder due to no more residual vacuum.
If the pedal feel is the same at the beginning of this procedure as at the end, you have a bad booster. If the booster won't meet the two additional stokes after the engine is shut off, you have a bad check valve on the vacuum line or a bad booster.
