Brake booster question!
Thread Starter
Burning Brakes
Joined: Dec 2004
Posts: 1,234
Likes: 2
From: New Jersey
Originally Posted by GiDvEtTe84
Thanks for the replies. I should have been more clear. I have already changed the booster a year ago w/ a rebuilt from a local parts house. My question is more about the action of the rod that passes through. It will not retract on its own. I have to set the screw right up against the MC so that it can push it back in. Is this correct? Brakes are hard then good then hard etc.......
The tip of the rod (the set screw) is set at the factory and you should have around 5mm of tolerance between it and the master cylinder piston.
Inside the booster there are 2 rods the one attached to your pedal and the one that acts on the master cylinder.
Both should return when you let off the pedal. There is a very stiff spring than pushes back the entire diaphragm and valve housing. The rod is attached to this. If the rod can be pushed and pulled back and forth then it's obviously busted.
However, the rod can move up and down and side ways easily, but it takes force to pull it forward.
Carefully, apply the brakes fully and then grab hold of the rod with a pair of needle nose locking pliers (not to much pressure), then release the brake pedal. The rod should go right back and pull the pliers with it.
If you don't feel any tug then you have a problem.
Drifting
Joined: Apr 2000
Posts: 1,915
Likes: 0
From: Maurice, LA
No, i can pull the rod out w/ my finger like its not connected inside. I dont even need pliers. Seems the rubber around it might be messed up as well. I unscrewed the bolt to a 0mm tolerance and the brakes react much sooner but at a certain point, they bind really bad. The new booster is on order. I already changed the MC so i doubt its that. Thanks.
