Upon startup of my '97ZJ, the brakes seem to be somewhat 'locked'. I start it, put it in drive, let off the brake, and it just sits there. Pump the brakes 3 or 4 times and it's freed up and ready to roll.

I know the rotors are prone to warpage.. but this seems to be more of a caliper issue. Everything seems to be working fine after the 3 or 4 brake pumps.....

What do ya think??

Thanks!

 

The brakes have a vaccum operated power brake boost. Check your vacuum lines to make sure they are all secure and have no leaks. When you start the engine it may take a moment to get the vacuum up. When you start your engine, with brake pedal depressed, you should feel the brake pedal go down some.

When you stop the engine, you should be able to depress the brake pedal couple of times before the vacuum boost depletes.

Look at your engine intake manifold and you will see a hose from the manifold to the brake boost assembly.

 

Your calipers could be hanging up, or the soft lines going to them may be collapsing inside and restricting the flow from age.
Dan

 

Thanks much! ...it'll be a little while before I can deeply dig into this issue.. but certainly needed an idea of where to start.

Will keep you updated...