Brake chamber PM.

My own opinion is, if you have a truck that has 500,000 miles on it and you have no idea if or when they have ever been changed, I would change all of them, including the ones on the front. There is a spring inside of there on the front and they do get weakened over time and of course they get rusty etcetera etcetera.

Positively I would check for play in the S cams, because if you grease them they last almost forever but more often than not no one greases them and they will have wear.

And again, if it were me, if cams and all of that are good, I would change all of the brake Chambers and I would change all of the slack adjusters and keep the old ones for a spare.

If you have not already at the next brake job I would check the bearings and set the correct end play. Bearings can last an incredibly long time if they have good fluid and the correct end play.

And others will probably tell you no, but if it were me at the next brake job I would completely remove the bearings and inspect them and put new seals in.

Airlines themselves you have to look at them to see what condition they're in. If the lines are chafed or cracked or that type of thing then replace them. If they're in one piece and they're not brittle or any of that that's not a problem you can let that go.

I like to do things this way because then if all of your wheel seals have been replaced and you have inspected all of your wheel bearings and you know that your cams and your brakes and your drums and your slack adjusters and your air cans everything is new, then you can completely forget about your brakes and your bearings and everything else.

To me, there's nothing worse than having one air chamber blowout and you fix it and then another one blows out in 3 months and then a wheel seal goes and then a slack adjuster goes...

That's the kind of thing mechanically I can't stand even a little bit. Finish it, you have nothing to worry about, be dependable, and move on to the next thing when it's time . Then fully complete that and you can cross that next thing off your list.

That's the way I do it anyway.

 

S cams that are greased regularly still can get worn on the "S" part to that moves the pin the shoes sit on too.

 

They all have equal wear on them, change them at your convenience and do all at the same time. Unless you like paying Billy bobs bend ya over road service.
Airbags I change at 500k all including cab.
Carrier bearing coming up soon as well. Just give yourself piece of mind

 

No one going to mention the danger of opening up a brake can ?
open it up without caging the spring and you’re a dead man.
the spring inside will shoot out with plenty enough energy to kill you


i replaced them on my trucks .

I used to carry a spare can.
It just a few bolts and a cotter pin .

Friend of mine walked into a shop a few months ago
And their new mechanic was holding a parking brake can agains his chest while removing the clamp that holds the diaphragm on .

he yelled at the mechanic and explained what was fixing to happen , which the mechanic didn’t believe until he was shown a couple of YouTube videos .

 

I think we are all presuming a level of competence from op given he mentions correct component parts and wants to avoid "caging a brake on the side of the road"

 

I bought new bendix cans for my trailer, you can’t piggy back them. Both clamps are now non serviceable bands. Like everything else disposable. Still have some 30/30 diaphragms with me and a type 20 diaphragm. I guess use them as small parts trays

 

S Cams seem to wear just from looking at them wrong!. Don't miss changing those every few years on my old trailer

 

On my tractors I always added parking brakes on the other drive axle ,
Much stronger holding power ,
And then I carried a spare replacement can .

 

I agree with your thinking 100%. Might as well replace them all Except he one you already have. Trust me more are soon to go.

 

It is strange they're only one half the tandem usually.