My Vette can’t get a full pedal…& should I rebuild the suspension along with the steering gearbox?
I have a problem with the brakes on my 1960 C-1 Corvette with 63,000 miles. Despite my best efforts, I cannot get a full pedal. I have had the master cylinder re-sleeved, and have rebuilt the front wheel cylinders and replaced both rear ones. There are no leaks. I put speedbleeders on all four cylinders and then started bleeding at the driver’s rear, as per Corvette information. At this point I have used over two quarts of brake fluid and still cannot get a good pedal without pumping. Can you help?
I also have another question: My steering gearbox needs to be rebuilt. Would it be wise to rebuild the entire front suspension at the same time?
Most likely the cause of your brake fade is leaking cup seals on the piston in your single-bore master cylinder. The master cylinder employs a piston to apply hydraulic pressure to the wheel cylinders. This piston is equipped with cup seals to prevent fluid from leaking out of the pressure chamber. When not in use, these seals are at rest between the vent port and the replenishing port. When you apply your brakes, the piston pushes the seal past the vent port creating pressure in the pressure chamber and then through the hydraulic lines into the wheel cylinders.
If the fluid leaks past the cupped seals on the piston, the pedal will fade to the floor, and it then takes continuous pumping to regain and maintain pressure in the system. This could be caused by defective seals, or seals that were installed improperly or became contaminated with grit.
Take the master cylinder apart and inspect it carefully. In all likelihood a seal has become deformed or chafed and needs replacing. Put in a new kit, and when you get the master cylinder back together, bench bleed it before installing it in order to make sure it is operating properly.
As for overhauling the entire front suspension system on your Corvette because the steering box needs a rebuild, I would say that all of the suspension and steering components work together and wear together, and if no maintenance has been done to any of those components over the years, they may well all be worn out. If your Corvette has only 63,000 original miles on it, I would wonder why the steering box needs rebuilding. They normally last twice that mileage and more if they are kept lubricated.
But to determine the answer to your question, put the car up on a lift and check the tie rods and ball joints. Grab each component and try to move it around. There should be no slop or play in any of the joints. Grab each front wheel and try to move it back and forth and up and down. Once again, if there is play in the system, there is wear.
To check the springs, which are the most important part of the suspension, set the car back on the ground and sight along the bottom of it front-to-rear. Is the car lower in front than in back? Does it lean to one side in front? If so, the front springs are probably tired from bearing the weight of the engine.
A better, more accurate check would involve some measurements of spring height and ground clearance at the chassis to see if they agree with the dimensions stated in your assembly or shop manual. And if the front suspension and steering is sloppy and sagging, I would rebuild the rear suspension as well, because if the front end didn’t get proper maintenance the rear didn’t either.