Forum: HoseHeads Sprint Car General Forum (go)
Moderators: dirtonly  /  dmantx  /  hosehead

i gotta guestion bout sprint car brakes....we have no pedal we have replaced the master cylinder..residual valve..front and rear calipers and we still have a soft pedal what would be ur suggestion?

Bleed them better

the first pump we get air than it all fluid on both front and rears 

prolly still air in lines. only pump pedal once then bleed again. sometimes if you leave it set a couple hours then bleed again.

ill give that a shot

I usually start farthest away from the cylinder and work your way closer to it.  Pump and bleed one time around and then once again.  You just might have a leak somewhere.  Start all over and check all your connections.  I know it's frustrating but then you find out it is many times the simplest thing you can imagine.  Good luck. 

My wife told me if I went to one more Sprint Car race 
she would leave me.................I'm sure gonna miss 
that ol' gal. 

Lots of front brake mounts don't leave the front bleeders at 12oclock.

the fronts are at 12

id go through the whole system. disconnect all lines and spray brake clean and air through all lines. I had the same problem. bled all calipers and replaced the master cylinders. Turns out there was a little pice of teflon tape in the steel line. Once we blew that out my brakes were as stong a hurcules!

also with the front caliper you might want to try taking it off the mount, and hold it higher than the master cylinder to help air to the bleeder. just make sure you have something in there to keep the pistons from moving like another rotor or something around the same thickness as the rotor

Rome wasn't built in a day......but they sure didn't
waste any time burning it down!

Are you running hard lines to the corners then running steel braided off those to the calipers ? 

And what bore M/C are you using?

I don't aim to please.
I aim to hit the target.

bleed the master cylinder.

had the same problem we had brakes but really nothing to brag about, finally i removed the residual valve completly, im a firm believer any small piece of debris in this spot killed our efforts to make the sysetem work as it should, in the off season i had a short visit with Wolfgang about my brakeing woes (pardon the pun), he recomended  honing the M/C even if it was a new jobber, we went to a larger m/c that could handel much more volume, I strongly recomend the LF steel rotor I use the "holy Crap pads from Krietz. this turns the car tremendously  when your stagger is less than preffered. keep them "new" they fade lightly after real abusive use, I proubly use mine too much!.  since the chat with Wolfie he got us in the ballpark with a little fine tuning to driver prefferance we have awsome brakes now.

also, ive always run the car , heavy vibrations that are much more than a few taps to the chassis free's up the air clinging to the walls of your lines, (think of it as a can of soda) we have almost always caught a few stragglers after the car was warmed and rechecked the system again.

I'm just impressed that there is a thread on Hoseheads that everyone is being helpful with and not arguing about something!

do it in the dirt

take the lines off  . blow em out . clean  everthing up. prolly  just  debris or sumthin stupid like that  

We are having the opposite issue at the moment.  Pedal is good and firm but the brakes don't stop the car very well.  Sitting in the shop, everything feels great, feels like everything is grabbing, once you're on the brakes you cannot budge the car.  But once on the track, the car slows down tremendously when applying the breaks but nothing that will lock up the tires.  Everything was brand new 12 races ago, calipers, rotors, lines, fitting, master cylinder, everything.  Car has not been in any crashes, no lines have been taken apart, nothing.  Any suggestions? Maybe pads glazed over or something like that?

Sounds like your pads are glazed over.  Take off and sand or file or however you like the hard shiny surface of the pads.  I set them on smooth concrete and slide across the floor will even work.  Make sure no oil like MUD off or whatever you use has soaked in as well. 

Bent rotor or the caliper is not square to the rotor. Most likely the left front mounts flex when the pedal is pressed and then flex when pressure is released and pulls the pads away from the rotor.Take the calipers off the car and put some inbetween the pads to test.