Rear air brake chamber for a 1970's GMC transit bus

[Dwayne Johnston]

Does anybody know what "type" of air brake chamber is used on a 1970's GMC Transit bus? Mine has no markings as rust has eliminated the stamping. It is actually the Maxibrake style with no ability to cage. I want to use a standard air chamber as I know they used both styles.

[Bill Gerrie]

My 5303 had what is called a Roto Chamber which I replaced with a long stroke regular 30/30. The Roto Chamber is available but very expensive. The standard 30/30 are only about $50 each.

[j.m.jackson]

Use a regular 30/30. I've got just a 30 on my 5303 Suburban (no spring parking brakes), and replacing that with a 30/30 and the necessary valves is on the list of things to do.

[Oonrahnjay]

Use a regular 30/30. I've got just a 30 on my 5303 Suburban (no spring parking brakes), and replacing that with a 30/30 and the necessary valves is on the list of things to do. 

    My bus came with a 3 1/2 foot long lever next to the driver's knee and a steel rod the size of your middle finger running all the way to the rear axle as the parking/emerg brake.  New chambers and the necessary valves makes the system actually work now (imagine that!!!) and gives me a system that I can depend on.

[buswarrior]

I would be a strong advocate for long stroke chambers, if there is room in whatever the application is.

Way more stroke for a buffer, and as we know, busnuts need as much buffer as they can get.

Too many busnut coaches consume a lot of stroke drawing up the worn bits... with little left to get stopped down the big hill.

Not right, but it is reality?

happy coaching!
buswarrior

[Bill Gerrie]

I never did like the single brake system on the older buses so I upgraded my system to a split one like all vehicles since 1975? I changed the foot pedal to an E6 and added another tank for a separate primary and secondary system. I did all the changes to make it the same as a newer split system to comply with the laws. It is so much better then the older system and wasn't that hard to do. Well worth the effort.

[Dwayne Johnston]

Thanks all for the replies. Sorry I had the wrong email in my profile and was not getting notifications.
I bought some 30/30s after much research. Long stroke is not until after 1996 and should not be put onto older systems according to Meritor support. They are for the newer brakes that have more brake shoe for longer intervals between services.
I will post up the before and after.

[dtcerrato]

We have the original brakes and chambers on our 53 4104. Upgraded to an E10 application valve with a well maintained drive shaft brake & "Johnson bar" at the left knee just like in-the-day. We do a lot of mountain driving and sometimes wished we had jakes but the brakes stop us well & so can the parking (emergency) brake when the air compressor should fail!

[chessie4905]

4104's have room for maxi brakes. Definitely worth the upgrade and not too expensive. Jake brakes are very nice to have on your coach as brakes are on the small side. I would have installed them on my 4104 if I hadn't moved to a 4905.

[TomC]

Easiest to upgrade to the same chambers trucks use. I know L.A. Freightliner sold Chinese made maxi-brake chambers for about $40-and according to the parts manager never had a return. Good Luck, TomC

[buswarrior]

Get that A$$ from Meritor to send that "advice" to you in writing, re: retrofit of long stroke chambers to older equipment.

Ill-informed made-up shite by some pup who talks smack.

I spent too long with too many brake peeps from too many vendors of too many brake parts back during the transition...

If they are all wrong, there's troubles bigger than this little hobby...

Long stroke chambers are a most excellent upgrade, wherever their longer bodies will fit.

happy coaching!
buswarior