Replacing brake cans/ Rod length

Make them both the same length. Make sure the operating range does not go less than the 90 degree slack to pushrod angle.

It is common for inexperienced to mis- measure pushrod length when replacing a complete chamber. If the mechanical park spring is broken and lodged and the chamber will not go full travel an incorrect measurment is easy to screw up.

All the more important to replace brake parts across an axle.

 

If your replacing slack adjusters also, there should be instructions and a s-cam adjuster card with them. Usually , the card snaps onto the slack adjuster pins and the Clevis should be adjusted to where the card lines up to the center of your s-cam shaft. With the park spring released.

 

And make sure you bolt the chamber in the right holes according to your slack adjusters length (5,5”.5”,6”). I know your working on a truck which are normally 6”, and many times don’t have holes for the 5or 5.5, but Incase anyone else might read this post to do this on a trailer, I figured it should be stated also....

 

I thought the proper length/ angle was 90 degrees,when brakes are applied. Wrong? Is it 90 degrees without brakes applied? Did I read @Goodysnap correct?

 

My post may have confused.

The angle should not exceed a right angle with brakes applied.

Best to follow the template with the slack provider as @Working2party suggested.

 

Probably has Meritor s-cam brackets, so by using their BSAP method distance should 2 3/4" + or - 1/8".

 

I read it wrong,just making sure,I think of pushrod going beyond 90 degrees point as being bad, but as you said, that would actually be less than a 90 degree angle, my mistake.

 

Many slack adjuster need the pushrod long enough to push the slack adjuster a-little past the 90 deg mark. (With the slack adjuster /bake shoes backed all the way off) That is so it can catch the next lug to adjust up.

When everything is properly adjusted and the brakes are set, the slack adjuster to chamber pushrod should not break the 90 as stated before.