Brakes question
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,014
Likes: 7
From: Ft Wayne IN
Brakes question
I have a 92 that I just purchased this spring. I have never had a C4 before so I don't know the brake quality. Anyways the brakes were horrible when I got it so I upgraded to C5 brakes, Made a difference but not the diff I was thinking. I am wondering if my power assist vacume thingy is bad. When I push the pettle it stops but seems like there isn't a whole lot of help. Is this normal for a C4? I pulled my vacume line goig to the power brakes and it is getting good vacume. I don,t hear any leaks at the check valve fitting. What is the best way to test the system? My 02 Tundra with little brakes grabs quicker and stops harder. If I drive the vette then get in my truck I tend to stab the brakes to hard at first????
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
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
First of all assume the brakes have not been maintained ever.
Get a couple of quarts of brake fluid (should take 1, may need a little to top off)
Flush the system at each wheel (I don't have my FSM, but I think its RR, LR, RF, LF)
Until you see the new fluid.
Push in the pistons and hit the brakes to see if the pistons are working.
Remove the calipers and grease/replace any slide pins.
Do a "Pump the brakes" bleed one last time and then drive it and see if the brakes are any better.
Get a couple of quarts of brake fluid (should take 1, may need a little to top off)
Flush the system at each wheel (I don't have my FSM, but I think its RR, LR, RF, LF)
Until you see the new fluid.
Push in the pistons and hit the brakes to see if the pistons are working.
Remove the calipers and grease/replace any slide pins.
Do a "Pump the brakes" bleed one last time and then drive it and see if the brakes are any better.
Race Director
Joined: Jun 2004
Posts: 13,953
Likes: 706
From: WI
What pads did you use? The C5 system isn't any better, though for me it allows a lower cost of rotors and pads for track use. Your choice of pad makes the most difference. If your not using it for track use then brake upgrades are for looks.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,014
Likes: 7
From: Ft Wayne IN
Done did all that, the brakes are brand new (C5) to include stainless lines and valvaline DOT 3&4 synthetic fluid ,beleive me it was flushed and flushed to include beelding the ABS system first. Hawk street pads mechanicly it is sound, just feels almost like manual brakes, there is some assist but not much, nothing like I thought a vette would stop like. Matbe Im excpecting to much for a 19 yr old technology. But when my pickup stop with less effort and smaller brakes in a heavier vehicle it just doesn't seem right. What do I need to do to check-out the Vacume assist canister (terninology??) the master cylinder bolts to it!
Race Director
Joined: Jun 2004
Posts: 13,953
Likes: 706
From: WI
HPS pads? Testing if the vacuum is there is easy, just detach the hose on the booster. Really you just need to tip it sideways a little to create a small air leak and there should be a loud hissing. This is with the car off. Bedding the pads helps too.
Thread Starter
Burning Brakes
Joined: May 2009
Posts: 1,014
Likes: 7
From: Ft Wayne IN
I pulled the line and it is getting good vacume to the booster. Is there much to go wrong on the inside of these things. Are there diaphrames that can leak so your not getting the full advantage? I bedded the brakes the way Hawk suggested?
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Race Director
Joined: Dec 2006
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<EDIT> of course Paul R. says the same thing I said in the post above this one. He is faster on the draw er um type!</EDIT>
On a lonely road or empty parking lot you could try low speed stops with the engine at idle and the engine off. Once you turn the engine off you should get at least 1 and 1/2 power assisted stops. If you don't feel any difference between the two then look to the power booster.
On a lonely road or empty parking lot you could try low speed stops with the engine at idle and the engine off. Once you turn the engine off you should get at least 1 and 1/2 power assisted stops. If you don't feel any difference between the two then look to the power booster.
So what you guys are saying is it pretty much works or doesn't work.
Melting Slicks
Joined: Aug 2008
Posts: 2,082
Likes: 50
From: Palmdale CA
I believe there is a Vacuum or ambient pressure throttling valve inside of the booster assembly, that is actuated when you step on the brake peddle, this allows the diaphram to move in the direction of Brake boost proportionally....My 95 will put you through the wind shield, so I would venture to say that your brakes are not right.
Melting Slicks
Joined: Aug 2008
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From: Palmdale CA
Melting Slicks
Joined: Feb 2009
Posts: 2,072
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From: Oklahoma City OK
St. Jude '10
I'm just like the OP, I have an 04 Chevy crew 4x4 that stops on a dime and my car w/ J55 brakes just stops. Mine will stop good if I apply ample pressure but certainly more pressure than I expect it should be.
There was a post here about a month ago about a valve in the master cylinder or booster that will disengage the rear brakes. I don't remember the whole thing but I think it was a safety feature in case pressure drops too low (as if a broken brake line) the rear brakes are blocked off so the front brakes can still stop the car. The original post was about not being able to bleed the brakes because nothing or very little will come out of the bleeder nut.
There was a post here about a month ago about a valve in the master cylinder or booster that will disengage the rear brakes. I don't remember the whole thing but I think it was a safety feature in case pressure drops too low (as if a broken brake line) the rear brakes are blocked off so the front brakes can still stop the car. The original post was about not being able to bleed the brakes because nothing or very little will come out of the bleeder nut.