Brake noise

[3810brad]

That is a correct statement from the last post and right on point on the grease fitting for greasing the s cams,although the service man states that the auto slacks should never need adjusting it is still a very good idea to check often cause they do get out of adjustment quit often.and the manuel also is right when it states that its probably because of some other failure in the system,it doesnt take much of a issue to cause the slacks to not perform the way they were intended.over greasing can even cause them to not adjust properly or even the wrong type of grease,the best grease we have found for them is stop master grease but also expensive 12 to15 dollars a tube,can be found in any heavy duty truck parts house.

[donwat91]

Fred, I believe that you're the only that has mentioned the S CAM. Believe you me that I have had it checked 3 or 4 times now by freightliner people and they can't find anything. So, I'm going to try this and I'll let you know the results. It may take me a little time to get done with the weather the way it is and my health.

[jbuening]

Fred Cooper is spot on!

[Fred Cooper]

Originally Posted by Hooligan

In the link FredCooper posted, the Air Brake Manual discusses "S cams" and also on page 72 it discusses how to reset and check the automatic slack adjusters. Automatic slack adjusters should never require adjustment, and if they are out of range, the adjuster has failed or there are other problems in the brake system..
Often by doing the sequence of full pressure applications of the service brake, the slack adjusters automatically center and this may are stop the clunk when brakes are applied..
The "S" cam shafts have a grease fitting and they should be lubed when chassis is lubed. Excessive grease could end up on the brake shoes...

From what I remember of looking at my coach when I cleaned and lubed the S cams, that grease fitting is for the rotating linkage that moves the S cam. The grease from the fitting does not reach the S cam or the corresponding rollers. You must clean the roller and cams, and put a very small film of hi temp grease on them.

[Pigman1]

Right on, Fred. In fact, Mike, at Camp Freightliner, recommends only about 3 pumps of the grease gun on the S cam shaft outboard zirk to prevent excess grease from migrating to the S cam area and dropping down on to the shoes and drum.