Brake Booster Removal & Replacement [Archive] - GrandAmGT.com Forum

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Stroll Troll
04-03-2010, 09:04 AM
I bought a 2000 Grand Am GT last year for my daughter. The vehicle had 76,000 miles on it and was in good shape. One thing wrong was the brakes didnít work properly. Stopping required pushing the pedal rather hard, almost as hard as the old manual brakes. This was clearly something that needed fixing.

Scouring the internet, I found the brake booster to be the likely culprit. No noises except a little creaking coming from what seemed the booster when pedal was being depressed. More scouring revealed little about R&R of the booster. The generic instructions that came with the booster fell a bit short when it came to the specifics of the 2000 Grand Am.

This prompted me to submit the following to your forum in hopes to help save some time for someone with the same project in front of them.

At first look the booster appears very confined, and it is. Not such a daunting task, though, for the moderately experienced back yard mechanic.

If you read nothing else from this post, read this. At first, I was planning on some short-cuts by removing as little as possible. I soon found out that these short-cuts would eventually require a hammer, possibly large. By removing the air filter box, the intake hose, the fuse box and the master cylinder enough room was created to slide the booster out with a little coaxing. I seriously donít know how you would do this without removing these items. R&R of these items is only about 20 minutes and well worth it. I will tell you the easy way to take these off, read on.

Safety, remove the ground from the battery. I know lotís of R&Rís start out this way, but I really would with this one as you will be playing with and near some wiring. Vent any vacuum from the booster by applying the brakes several times. The pedal will change to hard when vented. Remember brake fluid will wreck your paint (and probably your eyes) Protect both.

Then:

In the engine compartment:

Remove the air intake hose: Remove top of air filter box (2 screws) and the hose clamp closest to the engine. Remove the 3 sets of snapped on wires.
Remove bottom of air box. One 10mm nut and rotate out while pressing catch tabs on plastic intake vents. Be careful not to drop anything down the now open vent by the battery base. I dropped a grommet down there and had to get the vacuum out to retrieve it. Argghh :mad: This now makes room toÖ
Slide fuse box forward: Release the 2 clips holding the wire loom to the fire wall. Remove wire tab from master cylinder post, 1-15mm nut. Now this is the tricky part. Under the fuse box bracket (reach under from the engine side) there is a tab (a little forward from center) that needs to be press in (up). Tough to see and push. I used a curved needle nose pliers to get the umph. If necessary, use a mirror to look at it first, to see what it looks like. Slide the box forward while pushing the tab. The slack in the wires allows for lots of movement of the fuse box without removing any wiring (thank goodness). Now remove the bracket that the fuse box and air cleaner box were mounted to 4-10mm bolt/screws and 1-10mm nut. Now youíve got some room to work.
Remove the brake lines from the master cylinder 12mm open end wrench.
Remove master cylinder from booster: 2-15mm nuts. Keep cap on and level, set out of the way.
Remove vacuum hose from booster.


Inside the car:
Remove the two black panels under the dash. The left one needs to e removed first. Mine had one type of fastener that the center pin needed to be pulled first then the whole fastener would slide out. The other fasteners were4-8mm head screws. Some venting to be maneuvered, but not too bad.
Remove linkage from the brake pedal. Gently pry the flexible clip off the end of the pin, remove the marshmallow type spacer from the pin and the linkage will slide right off.
Remove the four nuts that hold the booster to the firewall. Socket, extension and 15mm socket will make quick work of this.

Back to engine compartment, slide Brake booster out using care to not put sideways pressure on the linkage arm that comes out of booster. Apparently this can wreck your new one or void the core return on the old one. Also be careful not to bend the brake lines as they like to get caught on the ridge of the booster as itís maneuvered out.

Now just reverse to put it all back. The instructions I had instructed me to bleed the brakes right at the master cylinder by loosening/tightening the brake line fittings just as you would with a bleeder screw as someone pressed the brake. Seems to have worked instead of the conventional bleeding (for now).

Might as well clean out the bottom of the air box while you have it out. After all itís probably never been upside down since the car was made (depending on how you drive the car). Also clean the screen between the air box and the intake hose(s)

Luckily, this (brake booster) was the problem and I now have power brakes for the first time on this car.

AaronGTR
04-03-2010, 10:52 AM
Good to hear that fixed the problem. I wonder if it really was the booster though or if bleeding the master cylinder and brakes line really was the problem? The booster going bad is actually a rather uncommon problem in these cars. Usually it's air in the lines from people letting the fluid get too low or not bleeding properly after replaced brake lines.

When I bleed my master cylinder I use a kit I bought from the auto parts store. It was pretty cheap and worked well. Has several different kinds of threaded plastic plugs with hose barbs on them to work in different cars. You put them in the two ports on the master cylinder and loop a couple short lengths of rubber hose up into the reservoir. This lets you depress the brake pedal repeatedly and circulate the fluid through the cylinder back in the reservoir to work all the air out before you hook up the two lines going to the ABS module. Then you bleed those lines by loosening the connections at the proportioning valve.

But yeah, you pretty much have to remove all that stuff to get the brake booster out. It's not that hard though and after they are out, it comes out pretty easy. The creaking you heard is probably just the pivot joint for the brake pedal. I've had that happen on both my cars. A little spray grease gets rid of it. :)

Stroll Troll
04-03-2010, 04:48 PM
I suppose it's possible, but my experience with brakes that need bleeding is the pedal is spongy. The pedal on this was hard (far from the floor) and hard to push. Like the old manual brakes.

The bleeder kit sounds worthwhile if I need to do it again. Hopefully not:applause:

masterjohnson
03-29-2011, 09:00 PM
Scouring the internet, I found the brake booster (http://www.racepages.com/parts/brake_booster.html) to be the likely culprit. No noises except a little creaking coming from what seemed the booster when pedal was being depressed. More scouring revealed little about R&R of the booster. The generic instructions that came with the booster fell a bit short when it came to the specifics of the 2000 Grand Am.

This prompted me to submit the following to your forum in hopes to help save some time for someone with the same project in front of them.

At first look the booster appears very confined, and it is. Not such a daunting task, though, for the moderately experienced back yard mechanic.

Then:

In the engine compartment:

Remove the air intake hose: Remove top of air filter box (2 screws) and the hose clamp closest to the engine. Remove the 3 sets of snapped on wires.
Remove bottom of air box. One 10mm nut and rotate out while pressing catch tabs on plastic intake vents. Be careful not to drop anything down the now open vent by the battery base. I dropped a grommet down there and had to get the vacuum out to retrieve it. Argghh :mad: This now makes room toÖ
Slide fuse box forward: Release the 2 clips holding the wire loom to the fire wall. Remove wire tab from master cylinder post, 1-15mm nut. Now this is the tricky part. Under the fuse box bracket (reach under from the engine side) there is a tab (a little forward from center) that needs to be press in (up). Tough to see and push. I used a curved needle nose pliers to get the umph. If necessary, use a mirror to look at it first, to see what it looks like. Slide the box forward while pushing the tab. The slack in the wires allows for lots of movement of the fuse box without removing any wiring (thank goodness). Now remove the bracket that the fuse box and air cleaner box were mounted to 4-10mm bolt/screws and 1-10mm nut. Now youíve got some room to work.
Remove the brake lines from the master cylinder 12mm open end wrench.
Remove master cylinder from booster: 2-15mm nuts. Keep cap on and level, set out of the way.
Remove vacuum hose from booster.


Inside the car:
Remove the two black panels under the dash. The left one needs to e removed first. Mine had one type of fastener that the center pin needed to be pulled first then the whole fastener would slide out. The other fasteners were4-8mm head screws. Some venting to be maneuvered, but not too bad.
Remove linkage from the brake pedal. Gently pry the flexible clip off the end of the pin, remove the marshmallow type spacer from the pin and the linkage will slide right off.
Remove the four nuts that hold the booster to the firewall. Socket, extension and 15mm socket will make quick work of this.

Back to engine compartment, slide Brake booster out using care to not put sideways pressure on the linkage arm that comes out of booster. Apparently this can wreck your new one or void the core return on the old one. Also be careful not to bend the brake lines as they like to get caught on the ridge of the booster as itís maneuvered out.

Now just reverse to put it all back. The instructions I had instructed me to bleed the brakes right at the master cylinder by loosening/tightening the brake line fittings just as you would with a bleeder screw as someone pressed the brake. Seems to have worked instead of the conventional bleeding (for now).

Might as well clean out the bottom of the air box while you have it out. After all itís probably never been upside down since the car was made (depending on how you drive the car). Also clean the screen between the air box and the intake hose(s)

Luckily, this brake booster was the problem and I now have power brakes for the first time on this car.

hello! bumping this thread i just wanna say thank you to you Stroll Troll. this is likely what happened to me i read this thread last to days ago then printed out a copy of what you said then followed what you did. this just save my money instead of going to dealership.