Hi guys, I'm troubleshooting a brake problem on my '66 fastback. It's a GT model, so it has factory disc brakes on the front. So far, I've had the original master cylinder, front calipers, and proportioning valve professionally rebuilt. Other than these items, literally every other piece of the brake system is new, and was replaced less than 2 years ago when the car was restored. The system is completely leak free, and we have bled both the front and rear wheels multiple times, as well as made sure the rear brake shoes are adjusted correctly.
The problem I'm having is that there just doesn't seem to be enough stopping force. Compared to my factory disc-brake equipped '65 convertible, the fastback's brakes are downright scary. It doesn't exactly have a mushy brake pedal, like something's leaking down or fluid is bypassing something, it just has a lot of pedal travel before you even get any brakes. And when the brakes start applying, it just feels like there's very little stopping power there. While I can stop the car, it feels like it wouldn't even lock the wheels if I ever had to panic stop.
A few months ago, I thought the original, rebuilt master cylinder might've been leaking down. I installed a new Raybestos master cylinder, but it didn't help anything at all. Since then, I've bled the system time and time again, I've driven the car a fair amount hoping the brakes might finally start to perform better, but so far, nothing works.
Could I possibly have the wrong pushrod for the master cylinder? I can't think of anything else it could be at this point. I've even thought about fabricating an adjustable pushrod to see if it helps any. Can anyone offer any more ideas? Does anyone possibly have a disc brake pushrod they could measure for me?
