brake booster

[terry82]

its time to replace my brake booster .i know its best to take out the seat any other tips .the dealer said thay no longer carry them .so far advance auto has the best price .

 

[lars]

Have you tested the booster to make sure it's "bad?" In my 35 years of working on Vettes, I've never actually seen a bad booster, but you could be the first... Most "booster problems" have to do with engine tuning issues, resulting in poor engine vacuum.

If it's actually ruptured, take it to a rebuilder and have it rebuilt. If you're shopping for "cheapest price," get rid of the Vette and get a Toyota.

I've never heard of removing the seat to remove the booster. I'm 6-foot and 220 pounds, and I can get a booster out without removing a seat. Are these guys pulling your leg..?

Lars

 

[terry82]

i have had three differant m/c on this car .the brakes feel the same .the pedal is hard .you have to hold your foot hard on the brake at a stop light .the motor has 18 inches of vacuume and is running at 650 rpm in gear at idle .the booster does hold vacuume for several days .the brakes stop well ,it just takes a lot of foot pressure to use the brakes .it does not feel like power brakes .if there is something else i can do or look at or check let me know .

 

[6880 Mike]

Are you certain the master cylinder is for power brakes? Sounds like a no-brainer, but I've been handed the wrong master cylinder a time or two over the counter at the generic parts places. Their numbers are not always correct.

 

[Vettehead Mikey]

I've never heard of removing the seat to remove the booster.

Maybe you've got a booster seat?

Mike

 

[SVO]

Complaints of a hard pedal is usually due to the wrong size master cylinder. Power brake master cylinder's have a 1 1/8" bore; Non-power brakes have a 1" bore. You wouldn't think that a 1/8" would make a difference but it does.

Also, if you get a brake booster from Advance, you will probably get one that was rebuilt by Cardone. I've found that their rebuild record to be "iffy" at times. For the time and effort to replace one, I'd go for one from Wagner or Raybestos.

As far as removing the seat, Yea, I've done that. It allows me to lay on my back on the floor with my feet kicked up in the storage area. May not be the best way, but it works for me.

 

[White75]

Check your MC first. It's a heck of a lot easier to try first.
My brake booster in my 75 was bad. You could hear the diaphram in ther weezing (sounded more like a fart though) I replaced that with one from Autozone and it was fine after that. However I went through 2 masters trying to get pedal. the first one was a brand new unit from a corvette shop and installed myself. After a lot of bleeding, I still couldn't get a firm pedal so the car was towed to the shop to have them try (maybe I was doing something wrong). Sure enough, bad MC and they replaced it and rebled everything.

as far as replacing the booster, a couple hints, if you are large or claustrophobic, you will be in a world of hurt. removing the seat does help. Me, I did it with the seat in and contorted myself on the floorboor and my feet were where my head would be on the seat. looked pretty funny according to my wife. I used a couple extensions (extends it out about a foot, a u-joint (swivel thingy) and a deepwell socket to reach up there. With that set up, I could use a ratchet with full range of motion from underneath the steering column as there is very little room to work right near where the nuts are. I was able to get it replaced in about 2 hours start to finish (and I'm usually slow and meticulous when working on the cars)

 

[terry82]

okay i will take off the m/c and measure the bore .is there any thing else on the m/c that will tell me if its a manual or a power?

 

[1yy07]

do what lars says if it is bad send it to Booster Dewey 503-238-8882 he does a good job. hope this helps

 

[6880 Mike]

okay i will take off the m/c and measure the bore .is there any thing else on the m/c that will tell me if its a manual or a power?

You can look for a GM casting/part number on it.

 

[terry82]

my booster may be half bad .i took the vac lines off the car and tested them with a vac gauge .two small leaks, put new clamps on .the vac line is now good .put it back on.the brakes are some what better but not like it should be.i will drive it this way for a while .thanks for all replys .

 

[SR'71]

adjusting power assist brakes

Have you tested the booster to make sure it's "bad?" In my 35 years adI've never heard of removing the seat to remove the booster. I'm 6-foot and 220 pounds, and I can get a booster out without removing a seat. Are these guys pulling your leg..? ....................I realize I'm responding to an ancient post. Lars , my booster was saturated with brake fluid that leaked past the master cylinder rear seal. Got repalcement parts .. but kept the origionals. Question ...... How do you adjust power assist brakes on a '71 454 4 speed ?
Lars

adding text because these IDIOTS keep telling me I am 2 [two] [II] characters tooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooshort