1988 Jeep Comanche Brake Issues!

[Samuhinso]

Hey everyone! New to the club. New to a Jeep Comanche all together, so much help is needed. Got the truck yesterday and I am concerned about the brakes. They are fairly easy to press, but I have to press down 3-5 inches in order for the brakes to start braking. Don't think this is normal, so what could the issue be? And what will be needed to fix the issue? 

 

Thanks!

 

[cruiser54]

Begin by inspecting and adjusting the rear brakes. 

[Pete M]

the link in my signature has a link with the instructions for proper bleeding.  MJ rear brakes have a different procedure than most anything else out there.   

 

also be sure to get your baby into the registry so you'll have your build sheet, birthday and selling dealership.  

[Eagle]

As previous comments have already addressed, unless the system has leaks the two things to check first are the rear brake adjustment, and bleeding.

 

If you are young enough that all your previous vehicles have had disc brakes on all four wheels, you may not be aware that drum brakes are different. With disc brakes, there are no springs to disengage the pads from the rotors when you release the brakes. Basically, they just stop applying pressure, and then normal driving may push the pads back just a bit. In general, the pads are always in pretty close contact to the rotors, so it doesn't require much movement to start applying the brakes.

 

With drum brakes, the shoes are held away from the drums by springs, to ensure that the lining material isn't in contact with the drum surface. The shows always retract to the same position, so as the lining material wears away the gap increases. This means more peddle travel before the brakes engage. There is an adjustment -- the star wheel, which is accessed from behind the wheels, through a slot in the backing plate. The MJ rear brakes are supposed to be self adjusting, but that doesn't work very well. IF someone hasn't messed up the self-adjuster so it won't work at all, making it work requires backing up and applying the brakes HARD, several times. I prefer to adjust manually rather than rely on the self-adjuster.

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And then there's bleeding. If you just bought the vehicle, you should bleed the brakes anyway, to flush out the old (who knows HOW old?) fluid, as well as to be sure there's no air in the system. Follow Pete's link -- the MJ has an emergency bypass circuit to the rear brakes, and bleeding the brakes using the normal procedure can't purge air from the bypass circuit. You MUST follow the recommended procedure.

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One other thing to check is to be sure the calipers are free to move.