brake problems?

Question

Have just bleed the brakes for my hot rod I'm building.They have disc's all round with a power booster.After bleeding the brakes the pedal only travels a bit and then becomes hard ( Normal operation I think )
After starting the car where the booster is being utilised the pedal travels very close to the floor.This dos'nt seam normal to me can anyone shed some light on the problem.

Thanks Nick

Answer 1

I don't know how you bled the brakes so I will explain in detail. Start with the furthest line back working your way forward. Have one person behind the steering wheel, at the brake pedal, pump the brakes three times. After the third time keep the pedal down. Have another person open the bleeder screw, watching for air bubbles, and drain the fluid. Close the bleeder screw and repeat the procedure several times. DO NOT LET OFF THE BRAKE PEDAL UNTILL THE BEEDER SCREW IS CLOSED! Make sure the master cylinder is full during this procedure. If the system is being filled for the first time you may have to do this a few times. If you don't have a stiffer pedal after each time, than you could be looking at some mechanical problems. The brake pedal will seem stiffer if you pump the pedal with the vehicle turned off and then once the car is turned on, holding the pedal down, you should get a couple inches of pedal travel. This is normal. When the car is off and you push the pedal you are building up tension in the brake booster. When you turn the car on manifold vacuum is supplied to the brake booster, releasing the tension. If your gut says there is still two much play still then inspect your brake springs and hardware. Check each wheel when applying the brakes and see if one spins easy. That will help narrow down and individual problem such as bad piston, incorrect spring routing, etc. You will also want to look for fluid leaks or loose connections on lines. Also spin each wheel and if you don't hear a slight grinding, if you have too much free-spin or no tension you may need to adjust your shoes tighter (if applicable). Doesn't sound like you have big problems just might have missed something simple? It happens. Good luck, hope this helps.

Answer 2

The pedal is just the booster taking in air it means that it's operating like it should... It's called Power Assist to see if your brakes are working properly after you've started your hot rod check and see how well it goes to the floor that's the vacuum for your power booster, and after you've started your hot rod pump the brakes to see how many times it's pumping before it gets hard should be like 3 or 4, 5 is unlikely for some reason... But yeah it's working fine...

Answer 3

Ok check your rod length in your break booster. And check that one way valve that runs from the hose from the intake manifold. If that is unhooked or not in there the brake booster means little.

Answer 4

may be air contained in the strains favor to bleed the brakes or the carry close cylinder may be undesirable or undesirable or leaking damage cylinders( seek for brake fluid on the floor by technique of the wheels the position you stop at) the emergency brake is run by technique of a cable may no longer be connected. if this became accomplished at a keep have them restore it suitable

Answer 5

power booster offer resistance when without vacuum.
yup, you're pushing agains the internals of the booster
when the engine is off.
open the garage door so you don't kill yourself with carbon monoxide. bleed it out with the engine running. uhhh, make sure it's in park or parking brake applied.