Please help!! front caliipers locking up and don't know why

[68firebird]

I've got LS1 brakes on the front of my firebird, I've got a new disc/drum master and prop valve, I have finally taken the car for a few rides and the front brakes stay locked, its happened the last 2 times I've taken the car out. I THINK that the calipers release after the car sits. It did it to me on friday night, sat all weekend till today and it did it again, raised the front of the car and can't spin either wheel. the back wheels seem to spin freely. any ideas?

[youthpastor]

we ran into this awhile back. What kind of master/ booster combo are you running? If it locks up again try cracking open the line to the front brakes off the master. If they release your problem is in the master/booster area

[68firebird]

It's a GM style master/prop valve combo from performanceonline.com. Supposedly made for disc/drum setup.

This is it

http://www.performanceonline.com/Disc-brake-Master-Cylinder-Proportioning-Valve-Kit-18817/

[Hydratech®]

The brake master cylinder is very likely not being allowed to achieve a full state of release, which seems to be a problem we are seeing more and more of lately with vacuum booster / aftermarket MC's (especially when spacer bullet / plug design MC's come into play).

Here are some links that will help get you squared away:

http://www.pro-touring.com/showthread.php?92619-Wilwood-Brake-Problems

http://www.lateral-g.net/forums/showthread.php4?t=17060

Do please remember to report back to let everybody know what you find, so that others can be prepared and learn from these scenarios in the future.

:cheers:

[71RS/SS396]

Make sure the booster piston/rod is not catching on the hole or rubber boot where it comes through the firewall. I've had this happen more than once.

[68firebird]

thanks for the help guys, will look into this asap. right now she is probably in the garage for the winter so I can take my time.

[MCB Matt]

The brake master cylinder is very likely not being allowed to achieve a full state of release, which seems to be a problem we are seeing more and more of lately with vacuum booster / aftermarket MC's (especially when spacer bullet / plug design MC's come into play).

Here are some links that will help get you squared away:

http://www.pro-touring.com/showthread.php?92619-Wilwood-Brake-Problems

http://www.lateral-g.net/forums/showthread.php4?t=17060

Do please remember to report back to let everybody know what you find, so that others can be prepared and learn from these scenarios in the future.

:cheers:

X1000

Seen it many many times...simple fix if its the case!

Good luck :lateral: