Re: ORED Toad Capacity
Reply #5 –
Brakes were a limiting factor on ORED air brake coaches. The 15x4 front wedge drum brakes do not engage at less than 60 psi or so. There is a Lq4 valve under the dash that unless heavy pedal pressure is applied stops them from working.
Why? Otherwise they squealed badly backing up. Nature of that particular braking system.
Why did Foretravel not use S cam brakes? Because the wedge brakes had full backing plates to keep rocks from being thrown up into the brake drum area off highway.
The legal tow capacity is on the data plate next to the drivers seat.
The cat units can tow more than the legal limits. I had one customer tow a 8 ton boat then mention the rear drums had smoke out of the wheels in use.
I had trucking company owners re route the brake lines under the dash to bypass the LQ4 valve to have all four brakes engage all the time.
Some changed the brake cans on the back of the backing plates to put more pressure on the shoes.
I learned to use the brakes hard enough to bypass the Lq4's engagement limit. Got on the brakes hard then coasted versus ride them constantly.
Some other brands used bus chassis that had giant s cam drum brakes. Problem was the timid rv drivers never got them warm enough and the shoes glazed. Required pulling the 300 pound rear drums off and then sand the shoes.
The smaller wedge cam brakes were tender in the Rockies if you were going fast always. Get on them hard then back off to let them kool for a bit. Downshifting helped a little. Some put in aftermarket exhaust brakes that were available back then.
Topic: ORED Toad Capacity