Tying into air break line for my TOAD

[Docg]

I have a 2006 Thomas HDX with air suspension and air brakes I am towing a car that is setup with an air brake system. It requires an airline from the Bus brake system to activate it when the bus brakes are applied. I’ve looked under the bus and there are airlines going every where. From the front of the bus there are large lines and small lines. The lines go into two control modules. One module for the parking brake and one for the regular air brakes. Has anyone hooked an airline into this system that goes to your TOAD?
Thanks

 

[Ozbozz57]

Yes, I have done it. Roadmaster supplemental system for a Suzuki Vitara. I tee'd off one of the rear service brakes with brass pipe fittings and ran a 1/4 inch nylon line to the quick connect coupling mounted on the rear bumper. Easy Peasy. It was harder fishing the line through the car to the breakaway reservoir and pedal cylinder.

 

[cadillackid]

how do those brakes modulate? do they get the same pressure as the rear service brakes? just wondering how you keep from locking the toad wheels up.. in a tractor trailer, the trailer brakes are modulated separately..

 

[Ozbozz57]

Toad brake modulation

Yes, the rear service brake pressure is fed unchanged to the toad. The air line is connected to a pneumatic cylinder affixed to the brake pedal and anchored to a solid point on the floor. In my Suzuki Vitara, I installed a bar across the driver's front seat bolts which has an anchor pin in the right position. I had to move the pin to a different spot on the bar to line up with the brake pedal, because I have an "ordinary" Vitara, not a "grand" one.

The Vitara is towed with the trans in 2nd and the transfer case in neutral, and needs to have the engine run to spin the trans/transfer case for a minute or so every 200 miles of flat towing. I have to remember to pump the toad's brake pedal afterwards several times to bleed off the vacuum of the power brakes before towing. I forgot to do this once, and locked up the toad brakes on the first brake application.

Braking force in the toad is proportional to the force in the bus. It seems to work well.

There is a solenoid valve operated reserve pressure cylinder mounted in the toad to stop the toad in the event of a breakaway. I hope I never have to find out how well THAT works.