Changing Brake Booster
Thread Starter
Intermediate
Joined: May 2004
Posts: 44
Likes: 0
From: Bradenton Fl.
Changing Brake Booster
Hi All
I was wondering if anyone can give me some info. on changing a brake power booster on my 78 corvette? I purchased a new mastercylinder and a brake booster in chrome and need to change it but never have before and none of the books I have tells me how to do it. Should I bleed the master cyl. on the bench like we did before? as it came as one unit? also is there a pin or bolt on brake pedel I have to take off/(I am disabled so is hard for me to get down under dash so was wondering if anyone could answer this before I tryed to get down there would make it easer for me if I knew ahead of time. If anyone has any info. thay could share with me that would be great you can E-Mail me direct at BigD924@aol.com
Thanks in advance
Dennis Stahley
I was wondering if anyone can give me some info. on changing a brake power booster on my 78 corvette? I purchased a new mastercylinder and a brake booster in chrome and need to change it but never have before and none of the books I have tells me how to do it. Should I bleed the master cyl. on the bench like we did before? as it came as one unit? also is there a pin or bolt on brake pedel I have to take off/(I am disabled so is hard for me to get down under dash so was wondering if anyone could answer this before I tryed to get down there would make it easer for me if I knew ahead of time. If anyone has any info. thay could share with me that would be great you can E-Mail me direct at BigD924@aol.com
Thanks in advance
Dennis Stahley
Melting Slicks
Joined: Dec 2000
Posts: 2,041
Likes: 0
From: Wichita, KS
You are going to be under the dash quite a bit doing this job.
Remove the drivers seat, remove the A/C duct below the steering column, remove the panel under the steering column, drop the steering column (some people prefer to remove it). Once you have gained access to the work area you will find an E clip on the pin that attaches the rod to the pedal arm, remove that clip and pin. Now there are 4 nuts holding the booster in place the easiest way that I have found to remove them is with a long extension, a universal joint and socket.
You do need to remove the master cylinder from the booster to bench bleed the unit before you install it.
Good luck.
Remove the drivers seat, remove the A/C duct below the steering column, remove the panel under the steering column, drop the steering column (some people prefer to remove it). Once you have gained access to the work area you will find an E clip on the pin that attaches the rod to the pedal arm, remove that clip and pin. Now there are 4 nuts holding the booster in place the easiest way that I have found to remove them is with a long extension, a universal joint and socket.
You do need to remove the master cylinder from the booster to bench bleed the unit before you install it.
Good luck.
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
I recently replaced the booster/master cylinder on the 72, and there were bench bleeding instructions that I had never seen before. There were 2 screw-in plugs for the line fittings with no provision for recirculating fluid. The instructions said to keep pushing the piston in ~1" until the movement was ~1/8" or less.
I actually did the bench bleed with the booster/cylinder in the car. I parked it on a slight incline, put a level on the master cylinder and jacked up the rear until the cylinder was level. It took dozens of pumps on the pedal to get to the 1/8" of movement but the pedal eventually did firm up. After that I just had to connect the lines and bleed the rest of the system.
In addition to what others said about removing the booster nuts, if you have a manual trans there is a neutral switch in the way of one of the upper nuts. Removing the switch gives much better access to the nut. Getting the switch back on, however, is a project in itself.
The whole thing is at least a 4 beer job. Good luck.
Rick B.
I actually did the bench bleed with the booster/cylinder in the car. I parked it on a slight incline, put a level on the master cylinder and jacked up the rear until the cylinder was level. It took dozens of pumps on the pedal to get to the 1/8" of movement but the pedal eventually did firm up. After that I just had to connect the lines and bleed the rest of the system.
In addition to what others said about removing the booster nuts, if you have a manual trans there is a neutral switch in the way of one of the upper nuts. Removing the switch gives much better access to the nut. Getting the switch back on, however, is a project in itself.
The whole thing is at least a 4 beer job. Good luck.
Rick B.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Originally Posted by 1979toy
You are going to be under the dash quite a bit doing this job.
Remove the drivers seat, remove the A/C duct below the steering column, remove the panel under the steering column, drop the steering column (some people prefer to remove it). Once you have gained access to the work area you will find an E clip on the pin that attaches the rod to the pedal arm, remove that clip and pin. Now there are 4 nuts holding the booster in place the easiest way that I have found to remove them is with a long extension, a universal joint and socket.
You do need to remove the master cylinder from the booster to bench bleed the unit before you install it.
Good luck.
Remove the drivers seat, remove the A/C duct below the steering column, remove the panel under the steering column, drop the steering column (some people prefer to remove it). Once you have gained access to the work area you will find an E clip on the pin that attaches the rod to the pedal arm, remove that clip and pin. Now there are 4 nuts holding the booster in place the easiest way that I have found to remove them is with a long extension, a universal joint and socket.
You do need to remove the master cylinder from the booster to bench bleed the unit before you install it.
Good luck.
Melting Slicks
Joined: Jan 2005
Posts: 3,347
Likes: 9
From: Salinas Ca.
Originally Posted by SIXFOOTER
Yep, thats the proceedure alright, but that one lil paragraph equaled about 4 hrs and at least 4 beers when I did it
I did it twice in a row...as the new booster was no good
managed to get the second one in...with two beers
Only thing I can add (with the help of this forum) is... duck tape the swivel joint to make it slightly stiffer. Needless to say, that top left nut is a ..... well, you know
Melting Slicks
Joined: May 2005
Posts: 2,826
Likes: 3
From: Tennessee
Originally Posted by Dick72LT1
What's the best way to hold the nut in the socket when working under the dash? I've heard grease suggested, but the potential for a mess is great.
I have found a piece/corner of paper layed over the socket and push the nut/bolt into the socket holds well for working it tight spaces.
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Instructor
Joined: Jul 2006
Posts: 159
Likes: 0
i changed the booster in my 74 and i didnt remove the drivers seat or a/c ducts. as a matter of fact the only thing i removed was the booster. it probably wouldve been easier removing the driver seat but why take it out when u can do it with it in???