1967 Manual brakes

[Joe L.]

Re: 1967 Manual brakes

Hello Don, Thank you for responding, as I stated in the original thread, I removed the aftermarket power brake master and booster and can say that the braking was not so great with the power system installed. Seems like there is something else going on here. Would you know if the proportioning valve would cause poor braking if defective?

John------


There is no proportioning valve on a 1967 Corvette unless you have a J-56 option.

Unless J-56. what you have is a "brake fluid distribution block and pressure warning switch" often mistaken for a "proportioning valve". It is possible for this to cause brake performance problems under certain conditions but I would not say that it's very likely to be the root of your problem.

[John C.]

Re: 1967 Manual brakes

I will go through the entire bleeding process again. Thank you.

[Leif A.]

Re: 1967 Manual brakes

I will go through the entire bleeding process again. Thank you.

Just a reminder, there are two bleeders on each rear caliper...an inner and an outer. Did you bleed both?

[Owen L.]

Re: 1967 Manual brakes

What type of pads did you install?
Have you done any sort of break-in or bedding of the new pads?

[John C.]

Re: 1967 Manual brakes

Yes, I bled both bleeders on the calipers multiple times. Also made sure to bleed both bleeders on the master. I also installed original equipment pads from Ecklers Corvette Parts.

[Joe L.]

Re: 1967 Manual brakes

Yes, I bled both bleeders on the calipers multiple times. Also made sure to bleed both bleeders on the master. I also installed original equipment pads from Ecklers Corvette Parts.

John-------


The master cylinder is best bench bled NOT USING the bleeder valves but using a master cylinder bleeding kit which includes fittings and tubes.

Bleeding the master cylinder on or off the car with the bleeder valves can be partially or completely ineffective. I expect that's why GM eliminated the master cylinder bleeder valves after about 1972.

[Joseph S.]

Re: 1967 Manual brakes

John, When you removed the Power Brake booster, did you also remove the small bracket from the brake pedal? The manual master cylinder clevis must be installed in that hole of the pedal in order to have the correct pedal ratio. If you have the clevis in the lower hole of the pedal, that might be your pressure issue.

[John C.]

Re: 1967 Manual brakes

I did investigate the position of the clevis and tried both positions with very little effect. Thank you for your input. I am going to remove the master cylinder and perform the bleeding process mentioned by Joe. Thanks to all for the very informative information.

[Edward J.]

Re: 1967 Manual brakes

John, sometimes when replacing disc pads and also if you had the rotors surfaces machined it may take about 50to75 mile to bed the new pads. Just make sure to to keep speeds down to be safe.you should note the stopping ability to get better the more you drive.

[John C.]

Re: 1967 Manual brakes

Ed, Thank you

[Steven B.]

Re: 1967 Manual brakes

Have a friend with a '66 L79 non power brakes. Bled brakes, MC, new pads, surfaced disc's and it didn't stop as good as before we started. Long story short after a couple more bleeds it would stop on a dime.

[Scott P.]

Re: 1967 Manual brakes

John,
Raise the rear of the car to level the MC.
Bleed the MC front and rear line connections and the bleeders.
I start bleeding with the LF then RF
Then LR then RR.
I use a pressure Bleeder.
New or used pad should not make a difference in stopping power.
Untouched or deglazed rotors should provide the same stopping power, if not brake fluid contaminated.
Corvette Rotors very seldom need to be turned. 65-82 at least.
Air will give you a soft pedal. No Air a hard pedal.
Push on the pedal when sitting still and hold pressure for a minute or more, the pedal should not go down. If it does there is a leak.
On a competitive level Corvette brakes are very good.
As your should be.
You will get there.
Scott

[John C.]

Re: 1967 Manual brakes

Thank you Scott, I will use your advice as well as all the other great tips from this thread.

[Randy R.]

Re: 1967 Manual brakes

i had a power brake master cylinder in my 67. A lot of effort was required to stop. I replaced it with a manual brake master cylinder. The amount of foot pressure required to stop was reduced. I think the piston diameter in a power brake master cylinder is larger.

Randy

[Timothy B.]

Re: 1967 Manual brakes

Randy, The master cylinder is the same in 1967 for power vs non power brake cars.