Adjusting brakes

They'll usually have you take it to a shop, check with your supervisor or manager to be sure.

 

suposedly you shouldn't have to adjust your brakes. with those new fagilled "self ajusting slack ajusters" I ajust mine about once a week even though all of the equiment has self ajusters. they just don't keep the brakes as tight as i like

 

I was taught that with self-adjusting brakes you back the slack adjusters off 1/2 turn, manual slacks get backed off 1/4 turn due to differences in the internal components. When the brakes are set, they should form about a 90° angle between the slack adjuster body and the rod coming out of the brake can.

 

When you look under the unit you should have a maximum 1.5 inches of brake rod travel with the spring brakes applied, you want at least 1 inch. When the brakes are cold. Use a tape measure, there are different tools required to adjust brakes for the different slack adjusters. If your company alows you to adjust your brakes or if you are an owner operator, and are not sure get someone to show you the proper method. Grease is the most important thing in a slack adjusters life. If it is withing specs leave it alone. Automatic slacks need to be installed at the proper angles to work properly, when you buy a new one you get a guage.
I really recomend you buy an infered temp gun, Sears sells a good one cheap, adjusting your brakes to tight will cost you a lot of fuel and needless brake wear.
If the brakes are out of adjustment apply 100 lbs brake application and hold for 5 seconds, to allow them to self adjust. This must be done when the brakes are cold, or you will have a dragging brake.
Be sure to do any brake inspection on flat ground and chock the tires.
Just a thought!

 

as a company driver....

Comply with whatever company policy is. Good way to get fired is to mess with brakes against company policy.

 

On newer trailers manufactured after a certain date that I can't recall, automatically adjusting slack adjusters are required, and have to be maintained. Swapping in a manually adjusted slack because its cheaper, or you prefer to determine clearances MIGHT land you in hot water, if it ever gets checked by an officer familiar enough with the regulations.

 

Self adjusters need several 90 psi applications to adjust into spec. This should be done daily and when hooking to a different trailer. As a bonus it often frees up any frozen brakes in the winter. I put zip ties on the push rods tight to the brake pots, this gives a really easy visual indicator of push rod travel.

Here in Canada it 1997 when the switch to self adjusters happened.

 

Dice got me going on this one....

Use an infrared thermometer to check your drum temps after you shut down. I found a couple of drums that were running about 25-30 degrees warmer. Can't say they were out of adjustment, just tighter than the rest. I backed them off just a bit, got them to re-adjust themselves again and they started to run the same temps as the rest now.

No clue if they will make much difference on my mileage. But if they reduce the brake wear as well, I am happy.