Fabman
Dances with Racecars
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- 8,204
- Exp. Type
- W2W Racing
- Exp. Level
- 20+ Years
I was at Thunderhill yesterday and a red flag was thrown at the end of the back straightaway.
I was clocking 135 when I saw the flag and just barely managed to get it stopped at the end of the straight.
I sat there for about 10 minutes while the track was cleared with my foot off the brake so the pads could cool. When I got back to my pit the pedal hit the floor.
Apparently the fluid boiled while we were sitting there which didn't surprise me after a panic stop like that and no cooling from the rotors sitting still.
What I didn't expect was that the brakes we dragging heavily. I let them cool and pulled a rear wheel and opened a bleeder.
No fluid came out but the wheel turned freely again. Today when I unloaded the car they were dragging again.
I put the car on the lift and all 4 wheels are dragging significantly. I backed off the master at the booster to be sure the push rod wasn't hanging the master open a little bit. Nope.
I then cracked the lines at the master and the exit lines at the ABS unit and no fluid came out and the wheels still drag. WTH is hanging them up?
[font=verdana, arial, helvetica, sans-serif]If there was residual pressure I would expect fluid to spurt out when the system is opened.[/font]
I will pull the wheels and inspect everything more closely this week, but WTH?
I have boiled fluid before a few times but not on an ABS car. What is going on here?
I was clocking 135 when I saw the flag and just barely managed to get it stopped at the end of the straight.
I sat there for about 10 minutes while the track was cleared with my foot off the brake so the pads could cool. When I got back to my pit the pedal hit the floor.
Apparently the fluid boiled while we were sitting there which didn't surprise me after a panic stop like that and no cooling from the rotors sitting still.
What I didn't expect was that the brakes we dragging heavily. I let them cool and pulled a rear wheel and opened a bleeder.
No fluid came out but the wheel turned freely again. Today when I unloaded the car they were dragging again.
I put the car on the lift and all 4 wheels are dragging significantly. I backed off the master at the booster to be sure the push rod wasn't hanging the master open a little bit. Nope.
I then cracked the lines at the master and the exit lines at the ABS unit and no fluid came out and the wheels still drag. WTH is hanging them up?
[font=verdana, arial, helvetica, sans-serif]If there was residual pressure I would expect fluid to spurt out when the system is opened.[/font]
I will pull the wheels and inspect everything more closely this week, but WTH?
I have boiled fluid before a few times but not on an ABS car. What is going on here?