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[C1] rear brake lock up

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Old 06-12-2019, 04:46 PM
  #41  
the skunk
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Hi,and thank you.
You took the time to read my boring list of attempts...
This condition existed before i had to work on the car.
So i went for replacing serviceable parts of the brake system.

Again: parts are new ,and have been checked for similarity.
Installation has been checked and double checked (if not 3 or 4,5, times)


I cannot lock the front wheels up...
How come?
Front hoses? (Sunsong brand,maybe 10 years old,looking good...)
Could this cause a surge of pressure to the rear?

Plus this: nose diving on left,and rear right uplifting on hard braking.
Uneven weight transfer caused by defective shocks,broken or bent spring ?

Combination of the two ,causing the RRW-lock up?

As soon as i lift my foot from the brake pedal,the wheel is freed and turns again: no residual or back pressure here.

Last edited by the skunk; 06-13-2019 at 02:46 AM.
Old 06-12-2019, 06:30 PM
  #42  
Westlotorn
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[QUOTE=JF in MI;1599571214]
Originally Posted by Westlotorn
Thinking about this Skunk, the rears keep locking up, right side unless blocked off then left side locks.
"One more note on this: The lines need to be equal in length from the T to the rear wheels. A longer line on the left or right side will cause delay in pressure reaching the wheel."

Lines from the factory are unequal length. Left side much longer than right, like on mine, and it stops fine.
Sorry if I misled on this system, I based my answer on what I know about Air Brake Systems in Class 8 Trucks, in air brakes it is critical to keep the lines of equal length. I assumed that applied to Hydraulic brakes also but as I think about it all hydraulic systems I know of show no concern for equal length lines. Front wheels always have longer lines to the passenger side. I should have thought of this. I will go back and edit the post so it does not mislead some other owner in the future.
Old 06-12-2019, 06:34 PM
  #43  
Westlotorn
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If you can't lock up your front brakes you have either a supply problem, not enough presurized brake fluid getting through to the front brakes.

I assume this is still a single master cylinder and not converted to a dual master cylinder?
Old 06-13-2019, 02:47 AM
  #44  
the skunk
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Right,single line master cylinder. (new)

Last edited by the skunk; 06-13-2019 at 02:48 AM.
Old 06-13-2019, 06:44 AM
  #45  
Frankie the Fink
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Originally Posted by the skunk
Hi,and thank you.
You took the time to read my boring list of attempts...
This condition existed before i had to work on the car.
So i went for replacing serviceable parts of the brake system.

Again: parts are new ,and have been checked for similarity.
Installation has been checked and double checked (if not 3 or 4,5, times)


I cannot lock the front wheels up...
How come?
Front hoses? (Sunsong brand,maybe 10 years old,looking good...)
Could this cause a surge of pressure to the rear?

Plus this: nose diving on left,and rear right uplifting on hard braking.
Uneven weight transfer caused by defective shocks,broken or bent spring ?

Combination of the two ,causing the RRW-lock up?

As soon as i lift my foot from the brake pedal,the wheel is freed and turns again: no residual or back pressure here.
Not to be a snit but if your front hoses are 10 years old you haven't replaced "all" serviceable parts.....folks are giving you advice about this stuff which you seem to be blowing past. 10 year old brake hoses "looking good" externally means nothing as I've previously said.

Soft parts of a brake system are the most vulnerable to deterioration and DOT 3 fluid is hygroscopic. Ten year old hoses on a car with unknown history and brake issues would get ripped off that car in 10 minutes in my garage. A little research shows that Sunsong brake hoses can be badly made - particularly the end fittings for Corvettes, Firebirds and other cars...

It could well be that the suspension is fine and the uneven braking is causing the sloppy handling when stopping. Tackle one issue at a time..

Once the brakes are straightened out, you should also go through the suspension carefully...does the car have the rear rebound straps, are the leaf springs original (they should have grooves in them), are the front chock mounting "tabs" in good shape ? These are notorious for cracking on these cars; see picture...



Nobody has mentioned it yet but there is a free online manual for the C1 cars:

http://chevy.oldcarmanualproject.com...csg/index.html

However, you will need a year-specific passenger car shop manual for generic things that they share with the Corvette, like brakes, charging system, etc..

Last edited by Frankie the Fink; 06-13-2019 at 06:58 AM.
Old 06-14-2019, 05:24 AM
  #46  
racefan2
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Brake hoses deteriorate from the inside. When you hit the brakes the lining inside swells and stops flow. They can look fine on the outside as Frankie said but they may not be. Change them, for peace of mind if nothing else.
Old 06-14-2019, 05:38 AM
  #47  
the skunk
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Hi and thank you.
I will.
Teflon stainless braided hoses on order...
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