Re: Has anyone driven a 1986 ORED GV 40 ft with NA Cat 3208?
Reply #11 –
Should be a 250hp 3208 with a turbo. 643 Allison. Oshkosh limited the front brakes to only work past 60psi.
Lq4 valve is in the dash to do this. Can be bypassed with or without a operating valve.
With the brakes fully engaged a shuddering noise and vibes are present in reverse. Nature of the brake shoe basic design.
I had trucker customers bypass the Lq4 valve so the brakes fully worked.
If you drive the coach and after fairly hard braking the front rims will be cool and the rears very warm.
With the Lq4 valve bypassed all the wheels warm up.
The Lq4 valve was a truck tractor valve which disconnected the front brakes so steering could be maintained in icy conditions.
Or save your braking needs until you can get on the brakes hard which then works the fronts also.
Average customer did not notice this very much. But hard drivers in the mountains noticed this.
A few customers changed the brake "cans" on the back of the wheels to a larger volume so the brakes were applied harder.
Had one customer install a marine twin turbo top end to his 250 cat. Wow. What hills.
He had 95k miles on the conversion. Only got into the throttle in 4th gear.
No trans or engine problems.
I would install a manual valve in the dash to allow on and off of the front brakes.
Bigger cans? Bigger turbo?
I drove the twin turbo coach. The idea of gearing it down is one way of using the hp instead of more torque.
I would regear it. Add the marine top end. Manual the Lq4 valve and then see if I wanted bigger cans on the wheel brakes.