Brake chambers..

wow....

Well you probably can't change it,but your mechanic can.

 

Ok just a couple things...

The air dryer may also be in front of the passenger steer tire. It is the thing that "pops off" when your air pressure gets built up to the maximum pressure. You hear the air pop off on trucks occasionally as they drive or are parked idling. It lets moisture out of the air system.

Do NOT try replacing the pancake on a brake chamber pod unless you know exactly what you are doing. I can't believe nobody has said yet, but there is a very powerful spring in those pods that can and most likely will be fatal if you take it apart wrong. Preferably take it to a mechanic and let them risk their necks.

 

Google air brake diaphragm. It's a rubber disc that won't cost more than a few dollars and is pretty quick to change out. Change out both on same axle. if you don't have any contamination in the air system you should be good with just that.

 

I don't know enough about it really to tell you how to do it right, I just know a lot of people have told me not to take it apart if I don't know what I'm doing. Also there are numerous other threads on here if you search brake pods that stress that.

 

Had a pancake type 20 chamber go bad and replaced both this week with new lines also. Total cost for parts less than $100 bucks and labor free of course.

Like others have mentioned before do not disassemble the chamber itself unless you know what you are doing as results could be fatal. From my understanding some chambers can be opened and diaphram replaced but maybe someone with more knowledge can chime in on that.

 

There are two rubber diaphragms in the maxi brake can. One holds air on to release your brakes when you are ready to move. (Yellow or red button). Other diaphragm takes on air psi every time you apply your brakes to stop. The heavy spring inside engages or applies brakes when you park by pushing out when you pull red or yellow knobs (parking brakes) that release the air inside the maxi brake or can. So..if you release brakes and you hear air escaping then the diaphragm that holds the coil spring from holding that brake has ruptured. If your ok there then keep brakes released and apply brakes and air is escaping then its the other air diaphragm. Of course chock wheels on level ground and all that stuff to check. The only diaphragm that is safe to change is the application one. The heavy coil spring one can POP out at you if you release clamp. Most newer maxis have a solid factory clamp that can't be undone on the coil spring end. Even newer ones have solid clamps on both. Sorry this is so long. Hope this helps.

 

You can't take the maxi apart without cutting it open. Been that way for decades.

 

You must mean on the coil spring end. The application diaphragm is so easy to change. Once you know how. I carry one with me and do it wherever I can park. Even carry a maxi not rocket science. Yes solid band on coil end for decades. But in and early 70s bolt clamps on both ends.

 

I replaced all of mine on Tractor, Drives, about 7 yrs ago, after 1 went bad. Used the black painted MGM brand. Haven’t had a 1 go bad. I think I have a broken parking spring on one of them now. Freightliner only has parking brakes, 30/30 dbles on 1 axle. Also have a broken spring on 1 on trailer. For this reason, along with rust issues, I’ll just change them all out on Tractor, again. Trailer, I’ll change just the 1 that’s broken. I carry a spare pancake, just in case I’m stuck somewhere, without parts available. Had that happen once, changed pancake only. I’ve noticed the cheap brake chambers, have a tendacy to wear a hole in the center of pancake. From the rod/ disc connection. I avoid cheap chambers. MGM, Bendix, or Midland. Worth an extra few bucks. There’s a few tricks to changing a pancake. Applying brakes, and using vise grips to hold the pushrod out, fully caging spring brake, can be tough, a deep socket, and air gun works best. Cutting new rod to exact length, and getting new fork/ pivot/ bolt/ pin. Makes for an easy job. Still a pita. Changing the whole chamber, with rusty bolts, isn’t any easier either. It’s worth $100 Labor to Me. As I’ve wrestled them in sub zero temps,when necessary. This summer, I’ll change all of mine, along with all of my airlines. And forget about it for another 5-7 yrs.