Bad replacement brake booster?
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
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From: Charleston SC
Bad replacement brake booster?
Recently, on my 94, I lost most of my braking ability and had a very loud hissing noise with the brake pedal depressed, so I replaced my booster (along with rebuilding all calipers, replacing stock hoses with SS, new pads, and a new master cylinder). After I finished the work, there was a very slight hissing, nowhere NEAR as loud as it was before the replacement. I've been meaning to check it out but haven't had a chance.
The other day I got in it and it took the force of my whole leg to get the car to stop, and the pedal was very stiff and felt like the pedal was barely moving.
Any help would be appreciated
The other day I got in it and it took the force of my whole leg to get the car to stop, and the pedal was very stiff and felt like the pedal was barely moving.
Any help would be appreciated
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
Likes: 0
From: Charleston SC
- Checked the ABS codes, there were none
- The replacement booster came with a new check valve pre-installed
I looked around in the dark with a flashlight for a while, and just as I was about to give up, I found a big crack in the booster housing.
Out of all the crap I did to it (completely rebuilt the braking system AND the whole front suspension), that !@#$%^& booster was the hardest part. Oh well, here we go again.
Thanks for the suggestions.
- The replacement booster came with a new check valve pre-installed
I looked around in the dark with a flashlight for a while, and just as I was about to give up, I found a big crack in the booster housing.
Out of all the crap I did to it (completely rebuilt the braking system AND the whole front suspension), that !@#$%^& booster was the hardest part. Oh well, here we go again.
Thanks for the suggestions.
Le Mans Master
Joined: Mar 2001
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
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St. Jude Donor '12
I know I can look it up in the FSM - just don't have time.
Other than being skinner that a shovel handle and as flexible as a pipe cleaner whats an easy way to pull the booster?
Do I need to remove the knee pad area under the dash and all that stuff first?
I'm doing the same thing you did - replace booster, master and all 4 calipers on my 92.
Any tricks to remove the parking brake cable from the rear caliper?
Other than being skinner that a shovel handle and as flexible as a pipe cleaner whats an easy way to pull the booster?
Do I need to remove the knee pad area under the dash and all that stuff first?
I'm doing the same thing you did - replace booster, master and all 4 calipers on my 92.
Any tricks to remove the parking brake cable from the rear caliper?
Drifting
Joined: Dec 2007
Posts: 1,329
Likes: 17
From: woodbury new jersey
i did a write up with pics when i did mine, you can see it here:
http://forums.corvetteforum.com/c4-g...with-pics.html
http://forums.corvetteforum.com/c4-g...with-pics.html
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
Likes: 0
From: Charleston SC
i did a write up with pics when i did mine, you can see it here:
http://forums.corvetteforum.com/c4-g...with-pics.html
http://forums.corvetteforum.com/c4-g...with-pics.html
I know I can look it up in the FSM - just don't have time.
Other than being skinner that a shovel handle and as flexible as a pipe cleaner whats an easy way to pull the booster?
Do I need to remove the knee pad area under the dash and all that stuff first?
I'm doing the same thing you did - replace booster, master and all 4 calipers on my 92.
Any tricks to remove the parking brake cable from the rear caliper?
Other than being skinner that a shovel handle and as flexible as a pipe cleaner whats an easy way to pull the booster?
Do I need to remove the knee pad area under the dash and all that stuff first?
I'm doing the same thing you did - replace booster, master and all 4 calipers on my 92.
Any tricks to remove the parking brake cable from the rear caliper?
What I'll add to the other write-up is that I used the 13mm socket on the 3" (i think) extension AND used a universal joint like THIS to hook that to a longer extension.
There is also a metal flange sticking down that will get in your way. After fighting it for probably 4 hours total (in probably 20 minute increments
) I realized that the flange was aluminum and is flexible, so you can flex it slightly out of the way to get to the nut.Make sure you unhook the booster rod from the pedal before you try to get to the nuts.
After doing it once and figuring out the tricks, I don't anticipate it being much of a problem this time - I just hope O'Reilly doesn't give me any crap about the warranty.
The process is very straightforward - I don't think I even looked at my FSM regarding getting the booster out. It's just a royal PITA to access those two nuts. Good luck
Last edited by aboveaveragejoe; Jan 13, 2010 at 09:59 AM.
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Instructor
Joined: Jan 2010
Posts: 174
Likes: 4
From: Austin_Palm Bay_Houston Texas_Florida_Texas
One thing I found to make this job a whole lot easier was to remove the steel knee bolster panel. With this removed, I did not have to lay on my back to get at the booster bolts, and you get great visual access as well. Only takes a couple minutes to remove this panel.
Cheers
Cheers
Last edited by Al Borman; Jan 13, 2010 at 06:13 PM.
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
Likes: 0
From: Charleston SC
Ok, this thing is about to drive me NUTS! 
Put in my replacement booster from O'Reilly today. Still have a very hard pedal, takes the whole leg to stop the car. As soon as I put the slightest pressure on the brake pedal, I hear a vacuum noise. While in park, if I hold down the brake pedal and hit the gas, for a split second the vacuum noise goes away and then returns.
Is it really possible that I'm having this much bad luck with reman'd boosters, or did I somehow screw it up putting it in? I can't really see how it's possible to screw up the install.
Put in my replacement booster from O'Reilly today. Still have a very hard pedal, takes the whole leg to stop the car. As soon as I put the slightest pressure on the brake pedal, I hear a vacuum noise. While in park, if I hold down the brake pedal and hit the gas, for a split second the vacuum noise goes away and then returns.
Is it really possible that I'm having this much bad luck with reman'd boosters, or did I somehow screw it up putting it in? I can't really see how it's possible to screw up the install.
Race Director
Joined: Apr 2003
Posts: 17,699
Likes: 1,667
From: moraga ca
Ok, this thing is about to drive me NUTS!
Put in my replacement booster from O'Reilly today. Still have a very hard pedal, takes the whole leg to stop the car. As soon as I put the slightest pressure on the brake pedal, I hear a vacuum noise. While in park, if I hold down the brake pedal and hit the gas, for a split second the vacuum noise goes away and then returns.
Is it really possible that I'm having this much bad luck with reman'd boosters, or did I somehow screw it up putting it in? I can't really see how it's possible to screw up the install.
Put in my replacement booster from O'Reilly today. Still have a very hard pedal, takes the whole leg to stop the car. As soon as I put the slightest pressure on the brake pedal, I hear a vacuum noise. While in park, if I hold down the brake pedal and hit the gas, for a split second the vacuum noise goes away and then returns.
Is it really possible that I'm having this much bad luck with reman'd boosters, or did I somehow screw it up putting it in? I can't really see how it's possible to screw up the install.
Instructor
Joined: Jan 2010
Posts: 174
Likes: 4
From: Austin_Palm Bay_Houston Texas_Florida_Texas
Do you hear the hissing only when you depress the brake pedal, or is it a constant hissing ? There is a chance that you got a bad remaned booster with a defective diaphram if the hissing is only heard when you are pushing down on the pedal. If this is the case, I feel your pain.
I assume the unit came with a new 1-way check valve. Anyway, make sure that this valve is not the source of the air leak.
I really doubt that you screwed up the booster during your install unless you badly mistreated the unit and slammed it into the firewall with total disregard..... (-;
There are 3 places that can potentialy leak:
1) booster (torn or ruptured diaphram)
2) booster check valve
3) Vacumm source at intake
The bad news is that if you can hear the hissing from inside the car, and the hissing is coming from the footwell area, chances are the booster is the culprit......
I assume the unit came with a new 1-way check valve. Anyway, make sure that this valve is not the source of the air leak.
I really doubt that you screwed up the booster during your install unless you badly mistreated the unit and slammed it into the firewall with total disregard..... (-;
There are 3 places that can potentialy leak:
1) booster (torn or ruptured diaphram)
2) booster check valve
3) Vacumm source at intake
The bad news is that if you can hear the hissing from inside the car, and the hissing is coming from the footwell area, chances are the booster is the culprit......
Last edited by Al Borman; Jan 18, 2010 at 09:49 PM.
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
Likes: 0
From: Charleston SC
Do you hear the hissing only when you depress the brake pedal, or is it a constant hissing ? There is a chance that you got a bad remaned booster with a defective diaphram if the hissing is only heard when you are pushing down on the pedal. If this is the case, I feel your pain.
I assume the unit came with a new 1-way check valve. Anyway, make sure that this valve is not the source of the air leak.
I assume the unit came with a new 1-way check valve. Anyway, make sure that this valve is not the source of the air leak.
I'll be picking up a Mityvac tomorrow to test vacuum on the booster. Fortunately, I learned the tricks on my first swap back in November. The swap today only took about an hour total, and should go even quicker if I have to swap again.
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
I had a DOA booster, many moons ago, when I replaced mine. The magic solution I found to get to those bolts was a tool called a semi-swivel, or wobble extension:
http://www.amazon.com/GearWrench-812.../dp/B000NI93AW
They let the extension move 10 degrees or so, but lock up when you push in on 'em. it's just enough to get all the way back there to the nuts.
I also used a little electrical tape to hole the nuts on the socket when I went to reinstall.
I'm 6' 5", 270 lbs and I did it without removing the seat....I did, however, wrench the **** out of my back when I burned my arm on the shoplight and smashed the socket wrench into the bridge of my nose.
http://www.amazon.com/GearWrench-812.../dp/B000NI93AW
They let the extension move 10 degrees or so, but lock up when you push in on 'em. it's just enough to get all the way back there to the nuts.
I also used a little electrical tape to hole the nuts on the socket when I went to reinstall.
I'm 6' 5", 270 lbs and I did it without removing the seat....I did, however, wrench the **** out of my back when I burned my arm on the shoplight and smashed the socket wrench into the bridge of my nose.
Instructor
Joined: Jan 2010
Posts: 174
Likes: 4
From: Austin_Palm Bay_Houston Texas_Florida_Texas
Anyway, when I installed a booster in my '93, I went ahead and spent the extra $$ on a new OEM Delco booster, because I did not want to have to do this anytime soon. New ones are going for about $265 from "thepartsladi" on fleabay. If that booster is toast, that would really suck. I think O'Reilly uses A1 Cardone for all their reman'ed stuff, FWIW.
If you are able to get your booster out without removing your MC, then you are a better man than I. I friggin' hated that job because I had to bleed the brake system, and yes, my back was feeling pain for days......
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
Likes: 0
From: Charleston SC
OMG !!! I almost fell out of my chair ...... I'm not laughing at ya', just the way you describe the series of events are hilarious.... Dayum, at 6'5", how do you even fit into the cockpit of a C4 ??
Anyway, when I installed a booster in my '93, I went ahead and spent the extra $$ on a new OEM Delco booster, because I did not want to have to do this anytime soon. New ones are going for about $265 from "thepartsladi" on fleabay. If that booster is toast, that would really suck. I think O'Reilly uses A1 Cardone for all their reman'ed stuff, FWIW.
If you are able to get your booster out without removing your MC, then you are a better man than I. I friggin' hated that job because I had to bleed the brake system, and yes, my back was feeling pain for days......
Anyway, when I installed a booster in my '93, I went ahead and spent the extra $$ on a new OEM Delco booster, because I did not want to have to do this anytime soon. New ones are going for about $265 from "thepartsladi" on fleabay. If that booster is toast, that would really suck. I think O'Reilly uses A1 Cardone for all their reman'ed stuff, FWIW.
If you are able to get your booster out without removing your MC, then you are a better man than I. I friggin' hated that job because I had to bleed the brake system, and yes, my back was feeling pain for days......
I definitely feel his pain. I did the swap today after snowboarding all day for the first time last Saturday (or should I say, spending all day Saturday bouncing down a snowy mountain on my azz...).I was actually able to get the booster off this time without removing the MC - I didn't even try last time since i was replacing the MC anyway.
Le Mans Master
Joined: Mar 2001
Posts: 7,999
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
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St. Jude Donor '12
If I EVER have to do this again I'm taking it to the shop. I like saving money by doing it myself, but this one has just been placed in the "shop" category.
Oh - the trick to removing the parking brake cable from the rear calipers: Take a good size flat blade screwdriver and while applying pressure on the cable push in the three spring fingers one at a time.
Thread Starter
Burning Brakes
Joined: Feb 2008
Posts: 1,000
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From: Charleston SC
Well, I picked up this kit tonight: http://www.harborfreight.com/cpi/cta...emnumber=92474
I hooked it up to the booster, and pumped it probably 20-30 times and got no vacuum at all. Does that mean the booster is toast?
I hooked it up to the booster, and pumped it probably 20-30 times and got no vacuum at all. Does that mean the booster is toast?