Brake Boost Question
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Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
Brake Boost Question
How do I know if my break booster is bad. I had the car worked on by a great vette mechanic, he says the booster may be bad.
The car seems to break fine to me.
Is there anyway to test for certain if it's bad?
If so, how difficult are these things to put in? Are the firewall bolts hard to get to? How many are there?
Thanks.....
The car seems to break fine to me.
Is there anyway to test for certain if it's bad?
If so, how difficult are these things to put in? Are the firewall bolts hard to get to? How many are there?
Thanks.....
Racer
Joined: Apr 2006
Posts: 405
Likes: 1
From: Twinsburg OH
Attach a vacuum to the port and see if it will hold vacuum. Mine was so bad I could just suck on it by mouth and never feel any resistance. There are 2 bolts holding the master cylinder on they are easy to get off. Then 2 more holding the booster to the firewall, 1 is easy the other is a pain in the you know what. I ended up taking the seat out just to have a little room to move my arms working under the dash and that’s when I finally got it.
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How do I know if my break booster is bad. I had the car worked on by a great vette mechanic, he says the booster may be bad.
***did he tell you WHY it "may be bad"?
The car seems to break fine to me.
***no exessive braking effort with your foot?
Is there anyway to test for certain if it's bad?
***you will have crappy brakes with excessive foot effort on the brake pedal and if you pump the brakes you will hear a "wooshing" sound coming from it.
If so, how difficult are these things to put in? Are the firewall bolts hard to get to? How many are there?
***kinda a pain in the a$$ from what i have read. i put one in an 81 and as with most c-4's, getting acess to the bolts above the brake pedal on the firewall is a bit difficult and some say it is best to remove the seat for better access....two bolts attach it.....
Thanks.....
***did he tell you WHY it "may be bad"?
The car seems to break fine to me.
***no exessive braking effort with your foot?
Is there anyway to test for certain if it's bad?
***you will have crappy brakes with excessive foot effort on the brake pedal and if you pump the brakes you will hear a "wooshing" sound coming from it.
If so, how difficult are these things to put in? Are the firewall bolts hard to get to? How many are there?
***kinda a pain in the a$$ from what i have read. i put one in an 81 and as with most c-4's, getting acess to the bolts above the brake pedal on the firewall is a bit difficult and some say it is best to remove the seat for better access....two bolts attach it.....
Thanks.....
Last edited by Da Mail Man; Aug 14, 2007 at 03:26 PM. Reason: bolt count error
Thread Starter
Team Owner
Joined: Oct 2004
Posts: 35,065
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
"seems to be hard to push"....
I don't feel it's excessive, but I only drive my car and have nothing to compare to. He drives all different cars to drive and compare.
***you will have crappy brakes with excessive foot effort on the brake pedal and if you pump the brakes you will hear a "wooshing" sound coming from it.
I don't hear a wooshing, and the brakes don't seem so "crappy". However, see above.
Are there four bolts on the firewall, or two?
Taking the seat out is a peice of cake, I don't mind that. I looked under the dash by the break pedal. There are two holes in the rubber mat that covers the inside fire wall. Are these the two bolts that hold the boost to the firewall?
***no exessive braking effort with your foot?
***you will have crappy brakes with excessive foot effort on the brake pedal and if you pump the brakes you will hear a "wooshing" sound coming from it.
***kinda a pain in the a$$ from what i have read. i put one in an 81 and as with most c-4's, getting acess to the bolts above the brake pedal on the firewall is a bit difficult and some say it is best to remove the seat for better access....four bolts attach it.....
Thanks.....
Thanks.....
Taking the seat out is a peice of cake, I don't mind that. I looked under the dash by the break pedal. There are two holes in the rubber mat that covers the inside fire wall. Are these the two bolts that hold the boost to the firewall?
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"seems to be hard to push"....
I don't feel it's excessive, but I only drive my car and have nothing to compare to. He drives all different cars to drive and compare.
I don't hear a wooshing, and the brakes don't seem so "crappy". However, see above.
Are there four bolts on the firewall, or two?
Taking the seat out is a peice of cake, I don't mind that. I looked under the dash by the break pedal. There are two holes in the rubber mat that covers the inside fire wall. Are these the two bolts that hold the boost to the firewall?
I don't feel it's excessive, but I only drive my car and have nothing to compare to. He drives all different cars to drive and compare.
I don't hear a wooshing, and the brakes don't seem so "crappy". However, see above.
Are there four bolts on the firewall, or two?
Taking the seat out is a peice of cake, I don't mind that. I looked under the dash by the break pedal. There are two holes in the rubber mat that covers the inside fire wall. Are these the two bolts that hold the boost to the firewall?
...i myself have crappy "fred flintstone brakes" that i have been fighting with for 2 years and am not much farther ahead then when i started!...it would be my opinion that if you can apply the brakes without much effort at all, your brakes may be fine...i have a toyota and those brakes blow my 88 vette's totally away!...drive someon elses' car and do a comparison as the amount of effort is subjective...
Last edited by Da Mail Man; Aug 13, 2007 at 06:57 AM. Reason: corrected number of bolts
Thread Starter
Team Owner
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
....is there any way you can apply a vacuum with a hand pump to the brake booster line and see if it holds vacuum?....also, you could have a leaking or defective booster ck valve...i think that 4 bolts hold the booster in and you have to take off the hush panel to acess them...heat with the plastic vacuum boosters and time sometimes rupture the booster but, you'd hear it!
...i myself have crappy "fred flintstone brakes" that i have been fighting with for 2 years and am not much farther ahead then when i started!...it would be my opinion that if you can apply the brakes without much effort at all, your brakes may be fine...i have a toyota and those brakes blow my 88 vette's totally away!...drive someon elses' car and do a comparison as the amount of effort is subjective...
...i myself have crappy "fred flintstone brakes" that i have been fighting with for 2 years and am not much farther ahead then when i started!...it would be my opinion that if you can apply the brakes without much effort at all, your brakes may be fine...i have a toyota and those brakes blow my 88 vette's totally away!...drive someon elses' car and do a comparison as the amount of effort is subjective...
SO, pull out the seat, take off the bottom of the dash, and twist your body in un natural positions to get it out.
It's a simple unbolt, rebolt.
Now, for the big question. I was going to spend the cash and get the plastic one, once I decided to do it, are the metal ones better for any reason?
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I can get a METAL booster for under $200. Some sources closer to $100. If it's $100 and a few hours work, screw it, I'll just do it.
SO, pull out the seat, take off the bottom of the dash, and twist your body in un natural positions to get it out.
It's a simple unbolt, rebolt.
Now, for the big question. I was going to spend the cash and get the plastic one, once I decided to do it, are the metal ones better for any reason?
SO, pull out the seat, take off the bottom of the dash, and twist your body in un natural positions to get it out.
It's a simple unbolt, rebolt.
Now, for the big question. I was going to spend the cash and get the plastic one, once I decided to do it, are the metal ones better for any reason?
Thread Starter
Team Owner
Joined: Oct 2004
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From: Bergen County, NJ Democrats, doing for the country what they did for Michigan
...look, if it isn't broken, DON"T fix it!...(but, that's up to you)..the metal ones may last longer as they are metal.... reinstallation of the booster bolts is difficult but, with a few extensions and swivels, is do-able...autozone and advance auto parts sell the metal ones rather inexpensivly...
The plastic is stock, and I was going to keep it that way, however, if there's nothing wrong with the metal ones, I'd look at those.
Believe me, I don't want to twist myself up under the dash for no reason. I just want to see if there's actually a problem.
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Racer
Joined: Oct 2006
Posts: 457
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From: Cincinnati Ohio
I just replaced mine about a month ago. However my problem was obvious, Car would not stop!! I bought a plastic booster from my local parts store for $115 + $35 core charge. My son put mine in for me and it took him about 45 minutes. Here are a couple tips I got on the forum and a nice link with pictures that helped a lot.
Take the drivers seat out, so that you can lay flat on your back when accessing the mounting bolts under the dash on the firewall near the pedals. Your back and neck will thank you, even if you're small/young. Just 4 bolts and the seat is out. It's worth the time.
Don't even attempt this job if you don't have some ratchet extensions and a wobble joint. Some of the booster mounting bolts under the dash are a pain in the *** to remove without this. Save yourself the grief, and get the wobble joint and extension before you do this.
You may or may not have to disconnect the brake lines at the master cylinder. You should able to just move the master aside far enough to fish out the old booster with lines still attached.
http://forums.corvetteforum.com/show....php?t=1725556
Hope this helps.. If you have to replace it..
Take the drivers seat out, so that you can lay flat on your back when accessing the mounting bolts under the dash on the firewall near the pedals. Your back and neck will thank you, even if you're small/young. Just 4 bolts and the seat is out. It's worth the time.
Don't even attempt this job if you don't have some ratchet extensions and a wobble joint. Some of the booster mounting bolts under the dash are a pain in the *** to remove without this. Save yourself the grief, and get the wobble joint and extension before you do this.
You may or may not have to disconnect the brake lines at the master cylinder. You should able to just move the master aside far enough to fish out the old booster with lines still attached.
http://forums.corvetteforum.com/show....php?t=1725556
Hope this helps.. If you have to replace it..
Last edited by Blak Z06; Aug 12, 2007 at 11:33 PM.
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Of course, I have to first determine it's broken. Maybe I'll get some local members with C4s and have them drive my car and tell me.
The plastic is stock, and I was going to keep it that way, however, if there's nothing wrong with the metal ones, I'd look at those.
Believe me, I don't want to twist myself up under the dash for no reason. I just want to see if there's actually a problem.
The plastic is stock, and I was going to keep it that way, however, if there's nothing wrong with the metal ones, I'd look at those.
Believe me, I don't want to twist myself up under the dash for no reason. I just want to see if there's actually a problem.
Racer
Joined: Oct 2006
Posts: 457
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From: Cincinnati Ohio
....agreed......and drive theirs but, just be sure they are not the j55 brake set-up as it would NOT be a fair comparison...a lot of guys are converting over to the j55 systems because they blow the stock systems away......the boosters (plastic) are a dime a dozen on e-bay and the olny decision you have to make is if you want to keep it stock....as for me, i have 2 spare plastic working boosters in the garage....."just in case"......ok, time for me to read the backs of my eye-lids for 8 hours......later!
except for the "dime a dozen part" I just looked on ebay and the cheapest plastic one I could find was $244.00
Racer
Joined: Apr 2006
Posts: 405
Likes: 1
From: Twinsburg OH
There are 2 nuts to remove the master cylinder from the booster, 2 nuts to remove the booster from the firewall, and a clip that disconnects the booster from the pedal. The hard nut to get at is directly above the steering column. I got this nut with a 1/4 drive ratchet and a 2" extension. It was a pain but worked after I had the seat and seat tracks out.
You might be able to tell if it is bad by just attaching a tube to the booster fitting and sucking on it. If you can not suck it tell you feel some vacuum building it is probably bad. A vacuum pump and gauge would be a better way to test it but if you’re like me you don't have one just laying around.
You might be able to tell if it is bad by just attaching a tube to the booster fitting and sucking on it. If you can not suck it tell you feel some vacuum building it is probably bad. A vacuum pump and gauge would be a better way to test it but if you’re like me you don't have one just laying around.
Drifting
Joined: Feb 2006
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From: CV ca
St. Jude Donor '11-'12-'13
When you are stopped, do you notice any change in the engine idle when you press or release the brake? This would be due to a tear/hole in the rubber diaphram inside the booster(vac leak).
You could also pull the vac line off the booster and cap the line, then see if there is any difference.
You could also pull the vac line off the booster and cap the line, then see if there is any difference.
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.....humnnn...could have sworn that there was four..oh well, i will edit my previous post...
Last edited by Da Mail Man; Aug 13, 2007 at 09:41 PM. Reason: spelling
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$70.00 each
and one purchase included the master cylinder that was "attached" to it....as with anything, you have to be dilligent and keep looking!.....so to me, they ARE a dime a dozen....
Last edited by Da Mail Man; Aug 14, 2007 at 03:30 PM. Reason: spelling
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When you are stopped, do you notice any change in the engine idle when you press or release the brake? This would be due to a tear/hole in the rubber diaphram inside the booster(vac leak).
You could also pull the vac line off the booster and cap the line, then see if there is any difference.
You could also pull the vac line off the booster and cap the line, then see if there is any difference.
Last edited by Da Mail Man; Aug 13, 2007 at 09:39 PM. Reason: spelling
Safety Car
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....haven't done anything with it yet although, today i slamed on the brakes and they worked like $hit!!..i almost hit the rear end of an suv after "standing" on the brake pedal...i am sooo pi$$ed off now that i may change out my booster even though it is holding vacuum!.....
Last edited by Da Mail Man; Aug 14, 2007 at 03:31 PM.