HELP!! after a short ride, my LS1 front brakes stay locked up!!!

[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?

[jprewitt]

I had a bad power brake booster do that once. That can also happen if you have a twisted brake line.

[1969sschevelle]

brake pedal adjustment? not allowing brake to fully release, has this problem with Dads Chevelle after disc brake installation

[Apogee]

brake pedal adjustment? not allowing brake to fully release, has this problem with Dads Chevelle after disc brake installation

X2...that would be the most likely cause. If you don't have free play between the pushrod and the master cylinder at rest, then it will not allow the brake fluid to return to the master cylinder reservoir when you release the brakes.

Tobin
KORE3

[68firebird]

thanks so much guys. I will try this asap. I don't think I have any play in it at the moment, I'm hoping that's the problem!!!

Edit: one other quick question, the master cylinder came with a piece that gets inserted into the master cylinder piston, I guess this is to make it shallow, so it can be used with or without. I currently have it in, should I be using it?

[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:

https://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:

[68firebird]

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:

https://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:

Will do!! I won't get to it till this weekend but I'll definitely let you guys know the result. from everything I'm told this is most likely the issue. thanks again guys!

[68firebird]

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:

https://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:

Paul, or anyone for that matter, should I be using that spacer bullet/plug with manual brakes? I currently have it installed because my old MC didn't have the spacer but the spacer brought the plunger or piston to where the stock one was, which is they way I assumed it should go. but after looking at Pozzi's 1st gen site he says to make sure your not using the shallow version because the rod can fall out using manual brakes, which I am. I'm a tad confused on what I should be doing since the stock MC was shallow. This is where I was reading it. http://pozziracing.com/brakes.htm#Booster
this is what I'm talking about.
https://static1.pt-content.com/images/pt/2012/10/mcrear-1.jpg

My original looked like the right one, but the new one looks like the left, but I have the spacer in to make it similar to the right. I'm sorry if I'm being overkill on explaination, just wanna make sure I'm describing it correctly, I'm a noob, LOL.

[Olav]

Last time i changed pads and rotors on my Tahoe I had simular issues. I replaced hoses and did work on the calipers but no good. After a while I found that the new pads was to thich and was slightly rubbing the rotors. After driving the rotors grew bigger because of heat, and hotter and hotter and almost locked up. I put back the old pads, problem solved. The wheels was turning free with the new rotors and pads but was obvisouslyon the "limit"

[MonzaRacer]

Get them locked again, then loosen up master cylinder and see if they release, if so the "plug" may be too longholding some preasure on the brakes.

[MonzaRacer]

Also as for rods falling out of master cylinders pedal stops and properly placed springs to keep pedals from rattleing help a lot.

[shep]

If you wind up not using the plug I would gladly take it off your hands. I need one to use my original master with the hydroboost unit I have.

[Birdbrain]

are you using a front disc, rear drum, metering valve? its bolted to the master cylinder stud and it has a reset button on it. It was intended to keep the front calipers from bleeding down so that the discs would engage faster than the drums. that thing causes all kinds of funky problems when doing brake conversions. if using 4 wheel discs best thing to do is elimintate it.