limited brakes
Thread Starter
Intermediate
Joined: Jan 2012
Posts: 45
Likes: 0
limited brakes
have a 72 vette without a power brake booster, to stop the car I have to put a lot of pressure on the pedal,and if I stomp on the brakes the car just slows to a stop without the wheels locking up,i know something is amiss but don't quite know where to start,any info would be helpful Thanks Alan
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Typical brakes for my '72, when I bought it in '95 had stainless lined calipers on it already, VERY hard to imagine any of these cars left today without stainless caliper bores lined in the old castings....
several things to check, and replace, the pistons/seals with O rings pistons/seals....the rubber hoses, check the damn run out on the rotors, shim with aluminum foil and flipping the rotor over on the hub to get minimum lateral play, keep the pistons from pumping and injecting either soft pedal OR AIR into the system, which is why a O rings, not the OEM lip seals.....
obviously you need to check that front/brass pressure switch that tells you if you have a front/rear brake failure, and lights a idiot light on the dash......that switch was a leak/failure point on my car.....
So after trying to fix/seal it, it failed again, so I just put in a separate front distribution block and so put the rear brakes to the m/cyl directly....and same with front.....
I have power brakes, but since you don't, I not commenting on that asspect of it.....another story.....
several things to check, and replace, the pistons/seals with O rings pistons/seals....the rubber hoses, check the damn run out on the rotors, shim with aluminum foil and flipping the rotor over on the hub to get minimum lateral play, keep the pistons from pumping and injecting either soft pedal OR AIR into the system, which is why a O rings, not the OEM lip seals.....
obviously you need to check that front/brass pressure switch that tells you if you have a front/rear brake failure, and lights a idiot light on the dash......that switch was a leak/failure point on my car.....
So after trying to fix/seal it, it failed again, so I just put in a separate front distribution block and so put the rear brakes to the m/cyl directly....and same with front.....
I have power brakes, but since you don't, I not commenting on that asspect of it.....another story.....
Thread Starter
Intermediate
Joined: Jan 2012
Posts: 45
Likes: 0
Typical brakes for my '72, when I bought it in '95 had stainless lined calipers on it already, VERY hard to imagine any of these cars left today without stainless caliper bores lined in the old castings....
several things to check, and replace, the pistons/seals with O rings pistons/seals....the rubber hoses, check the damn run out on the rotors, shim with aluminum foil and flipping the rotor over on the hub to get minimum lateral play, keep the pistons from pumping and injecting either soft pedal OR AIR into the system, which is why a O rings, not the OEM lip seals.....
obviously you need to check that front/brass pressure switch that tells you if you have a front/rear brake failure, and lights a idiot light on the dash......that switch was a leak/failure point on my car.....
So after trying to fix/seal it, it failed again, so I just put in a separate front distribution block and so put the rear brakes to the m/cyl directly....and same with front.....
I have power brakes, but since you don't, I not commenting on that asspect of it.....another story.....
several things to check, and replace, the pistons/seals with O rings pistons/seals....the rubber hoses, check the damn run out on the rotors, shim with aluminum foil and flipping the rotor over on the hub to get minimum lateral play, keep the pistons from pumping and injecting either soft pedal OR AIR into the system, which is why a O rings, not the OEM lip seals.....
obviously you need to check that front/brass pressure switch that tells you if you have a front/rear brake failure, and lights a idiot light on the dash......that switch was a leak/failure point on my car.....
So after trying to fix/seal it, it failed again, so I just put in a separate front distribution block and so put the rear brakes to the m/cyl directly....and same with front.....
I have power brakes, but since you don't, I not commenting on that asspect of it.....another story.....
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,594
Likes: 7,041
From: New Or-leens Loo-z-anna
I am not a person who replaces parts that I feel are "O.K."........
BUT..........................
If you can get 4 new flexible rubber brake lines that connect the calipers to the steel brake lines, it would be a very good and safe thing to do. Unless those hoses have been replaced by a previous owner, you should get new hoses, since they do not give you any warning when they decide to explode.
(Just the way my 40+ year old "O.K.-looking" engine heater hose did 2 days ago.....with me standing there with the engine running and the hood up-----NOT fun!)
As for the "pressure switch"..........on my '68 with manual brakes....it's a "diverter block/valve assembly" located under the master cylinder with 2 inlets and 2 outlets and 1 electrical connector....I'm not sure if your year-model is set up the same way.
If a brake line ruptures in the front, the diverter automatically bypasses the front brake system so that the master cylinder will not lose all the fluid----if a rear brake fails, the diverter sends the fluid to the front brakes until you can drive to a repair shop.
BUT..........................
If you can get 4 new flexible rubber brake lines that connect the calipers to the steel brake lines, it would be a very good and safe thing to do. Unless those hoses have been replaced by a previous owner, you should get new hoses, since they do not give you any warning when they decide to explode.
(Just the way my 40+ year old "O.K.-looking" engine heater hose did 2 days ago.....with me standing there with the engine running and the hood up-----NOT fun!)
As for the "pressure switch"..........on my '68 with manual brakes....it's a "diverter block/valve assembly" located under the master cylinder with 2 inlets and 2 outlets and 1 electrical connector....I'm not sure if your year-model is set up the same way.
If a brake line ruptures in the front, the diverter automatically bypasses the front brake system so that the master cylinder will not lose all the fluid----if a rear brake fails, the diverter sends the fluid to the front brakes until you can drive to a repair shop.
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Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
if you want a solid pedal, replace the rubber lines with
Stainless flex lines they do not swell, and will provide a more solid pedal feel.
of course all this brings you into the Brake bleeding world for corvettes,
research Brake bleeding corvettes, before you start.
Stainless flex lines they do not swell, and will provide a more solid pedal feel.
of course all this brings you into the Brake bleeding world for corvettes,
research Brake bleeding corvettes, before you start.
Drifting
Joined: Apr 2007
Posts: 1,970
Likes: 45
From: Cameron Park CA
Braided stainless hoses will make a world of difference. When the brakes are completely bled, you will have a very firm pedal, and a very secure feeling about the brakes.
Pete
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,594
Likes: 7,041
From: New Or-leens Loo-z-anna
Let us know the condition of the diverter"block".....I had to dis-assemble mine because it was stuck....the internal O-rings were in great shape, but "sludge" had completely jammed the small piston to one end of the block, and the "warning switch" was also seized because od sludge. It works perfectly since I cleaned/re-assembled it........
BUT BLEEDING THE 4 CALIPERS TOOK THE ENTIRE DAY.....this brake system is a MAZE!
BUT BLEEDING THE 4 CALIPERS TOOK THE ENTIRE DAY.....this brake system is a MAZE!
Thread Starter
Intermediate
Joined: Jan 2012
Posts: 45
Likes: 0
Let us know the condition of the diverter"block".....I had to dis-assemble mine because it was stuck....the internal O-rings were in great shape, but "sludge" had completely jammed the small piston to one end of the block, and the "warning switch" was also seized because od sludge. It works perfectly since I cleaned/re-assembled it........
BUT BLEEDING THE 4 CALIPERS TOOK THE ENTIRE DAY.....this brake system is a MAZE!
BUT BLEEDING THE 4 CALIPERS TOOK THE ENTIRE DAY.....this brake system is a MAZE!