Roto Chamber- To Maxi Brake Conversion

[Firemack]

Big Mack Air Brake Experts-

I am helping out a friend that has a 1960 Mack B95 Fire Truck with Air Brakes. This truck is holding air pressure when applying the brakes, but I can hear air escaping- so I am looking to find the leak and repair it. My first item to check is the rear chambers- and looking to get parts- they are not readily available as they are the old RotoChamber style. The new style chambers are available but need to add a valve and piping to make them release. I checked with Bendix and downloaded the latest manual- it has diagrams for the new braking systems but nothing on a conversion. I seem to remember a good reference on ATHS ro ATCA but cannot find it on their site any longer.

I wanted to know if anyone has already done the conversion and has a list of parts needed to convert this to Maxi Chamber (with air parking brakes). I am planning on replacing all of the rubber air lines and chambers as well during the conversion so he can be sure the truck will stop and not have to worry about blowing a line (or diaphram) going down the road.

Thanks,

Firemack

[Firemack]

Sometimes you just have the figure these things out for yourself! I made the changes to 1960 Mack B95 Fire truck and converted the rear chambers to type 30/30 with rear parking brake chambers. I rebuilt the front chambers with new diaphrams and added all new brake hoses. To add the parking brake, I added a line from the air brake tank to the parking brake control, and then back to a T mounted on the frame above the rear, and added the 2 parking brake lines to the parking brake chambers. I adjusted the slack adjusters to about 1/2" play and the truck stops great, and the parking brake works great also. Better safe with all new lines and safety of the dual rear chambers than sorry!

If anyone else wants to know about how to make the conversion I can draw up the air line diagram to add more details if needed.

Firemack