Brake Bleeding

[sideoiler10]

Have you found a solution to your spongy pedal problem? If you have, please relay it to me.

I also have a Shell Valley Motors cobra with what sounds like a similar problem. The original brakes on my car were the 9" rotors in the front and large drums on a 9" Ford rear. The brakes left a lot to be desired so I decided to upgrade to 11" rotors with large GM calipers in the front and 11" rotors with Cadillac Seville calipers(w/emergency brakes) in the rear.

I have bled and bled and rebled, including power bleeding but still cannot obtain a firm pedal. The brakes stop better than before, but I don't like the soft pedal. Sometimes it feels like I need to pump it once for it to feel properly.

It uses the separate Girling master cylinders for the front and rear systems (probably same as yours). I have checked and found that Girling makes 3 different size cylinders (pistons) that produce more volume of fluid to the calipers. I was thinking that perhaps I need to switch to a larger size piston to provide enough fluid volume to the larger calipers, but first I need to find out what size pistons are in my current Girling master cylinders.

I have contacted several Cobra assemblers but have received only limited comments. I was surprised that Shell Valley Motors couldn't help me at all. Do you have any suggestions or comments?

Thank you,

Bob