Trouble Shooting steer axle brakes. 2002 9400I

Check the spring pins make sure there is no movement there. You might need to place a small bottle jack between the axle and the frame to take pressure off the spring and pins.


If there is a problem with the brakes it should be obviouse when you get the drum off. Don't forget to check the s cam and bushings.

 

It could be the s-cam bushings allowing it to "jump" or it could be a flat spot on the "s" of the s-cam. If its a flat spot just rotate the s-cam a half turn. This should be done every time when changing brakes.

 

Could have a bad slack adjuster. May pull it and see if splines are worn/broken on cam or adjuster.

 

Check for cracks in the drums.

 

Since its a steer axle. When was the last time you replaced the drums, sack adjusters, cans, shoes, S cams and bushings? Honestly, if it has been a while, you should replace everything at once. Its not that much money, and if its your truck, it is a wise investment. I always order every part to do with brakes, less valves, and change it all at once. Then you can get that warm fuzzy feeling when mr DOT looks under there at your brakes during an inspection. Good luck.

 

There is a chance you could have a sticky brake chamber. The clunk is is the chamber applying either too slow, and when it does you feel it because it forcefully applies the brake on that particular side of your steer axle. Apply the brake and see if there is any delay, or if they chamber is slow to extend or retract. Try stabbing hard, medium and light to duplicate the problem. Thanks.

 

Clunks are almost always worn s cam bushings or the s cams themselves where they meet the bushings.