Air Brakes contain many parts, when inspecting or repairing it is best to replace components showing minor wear to insure that the system will function properly.

Make sure that the brake chambers are the same on an axle some of the earlier trucks had 24/30 chambers and the common chamber of late is 30/30 and I have seen them mixed, this will affect your braking, and now on newer models you will see 30/36 chambers just make sure you don't mix and match.

The first rule to remember when servicing axle's is always do things in pairs on the same axle, if you replace an auto-matic slack on the left side, you must do the right as well or it will affect your braking. Same goes with springs, shocks, drums, shoes.

One thing that really takes life out of brake linings is the drums, if you have any grooves from rocks or even a slight wave your braking will be reduced and poor. And your shoes will wear faster, and you risk the chance of the wheel hanging up on you because of the irregular surface. So replace the drums when you do shoes, there are very few times when you can get by without replacing them.

Another thing to look for is the s-cam bushing wear, try moving the cam up and down, if you feel slack, then put in a bushing kit. Another thing to look at is the bottom shoe you removed if it has 1/16 of lining towards the outside and a 1/4 inch of lining towards the inside, you know that your cams or bushings are worn.

Be sure to check your brake lines when inspecting or performing an overhaul, make sure they are not kinked or hanging down where they could be ripped off.

Always test the brake system after repairing it, make sure it functions properly before putting it to service on the road.

Drive Safe and thanks for reading.

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