drum brake problem

[icarl]

I just put on new rear brake shoes, drums and spring kit. i put the drum and tire back on and tighten the star wheel up so that i can not even turn the wheel by hand. With the rear jacked up the hand brake test works fine - the wheels stop when i pull the lever. But, when i push on the brake pedal the wheels just slow a little and do not stop. The wheels are just idling in 1st. So i took the drum back off and checked to see if the wheel cylinder was pushing the brake shoes out and they were. Why is the foot brake not working?

 

[icarl]

i think i figured it out. i am going to have to replace the wheel cylinders on both sides. I think i will just replace all the drum brake components.

 

[JeepJeepster]

I think he has the back of the jeep raised up off the ground so they should stop when he hits the brakes.

 

[JeepJeepster]

Yea, but he said he has the star wheel turned so tight that he cant turn the wheel. If its already that tight then the brakes should stop the wheel from turning if he hits the brake pedal.

Just make sure you loosen that back up icarl like tony said. It should turn freely.

 

[tjkj2002]

Rear brakes should never lock up like front brakes, if so the rear end would slide away everytime you hit the pedal.

There are pressure restrictors inside the rear cilinders.

No there is not.There is a little box that the lines from the master cylinder runs to first,that is the proportioning valve.That valve delay's the fluid flow to the rear brakes a fraction of a second so the front brakes apply first.If you have rear drums there is also a o-ring in the rear output that limits the amount of fluid since drums do not need the same amount of fluid as disc brakes.

 

[Dave]

The only thing I can think of is if you reversed the primary and secondary brake shoes when you put the new ones on.

Dave

 

[JeepJeepster]

Pretty sure the rear brakes do not have different pads for the ebrake. It uses the same pads that the brakes do.

And drums dont have calipers. I do believe the proportioning valve limits pressure, it doesnt delay the pressure. If it delayed the pressure then you would hit the brakes, slow down some, then the rear brakes would lock up.

Icarl may be right with thinking the wheel cylinders are bad. Had to replace those on our 94 grand and it was amazing how much better the brakes got.

 

[tjkj2002]

I do believe the proportioning valve limits pressure, it doesnt delay the pressure. If it delayed the pressure then you would hit the brakes, slow down some, then the rear brakes would lock up.

It does delay the rear brakes by a fraction of a second to allow the front brakes to apply first,where most of the braking takes place anyway from weight transfer.And with that weight transfer if the rear brakes applied the same time as the fronts did the rears would lockup.The valve does not limit pressure either,it does limit fluid capicity since the wheel cylinders are much smaller then the caliphers.

Now you can get proportioning valves that limit pressure,and that are adjustable but it they require a same brake set-up F/R and are mostly used for racing apps.