1981 f 800 diesal dump truck. Can't set park brake, lever does not move up. there is a big drum on driveshaft. I need direction to information about this brake system, how to adjust, identify and troubleshoot. The 4 wheel drum system stops truck well. it has hydroboost system. I just can not locate specific info and need your help to get this part of brake system operational. Park brake is helpful when working the truck. (haha) thank you in advance.

 

While your waiting on replies, have you tried the user Friendly ' Search ' feature ?

The archives here run real deep

Good Luck !

 

I have not messed with that type of system but do know of it.
That drum thing on the drive shaft / transmission is the parking brake.
It should have 2 shoes that press on the drum. They move by cable.

The lever when pulled up should lock into place keeping the brake on.
That lever pulls on the cable hooked to the shoes.
I think it also has a **** on the end to adjust it when the shoes wear down.

Only 2 things I can think of to keep the lever from moving.
1 lever is rusted in place but not likely.
2 the cable is rusted frozen in place vary likely.

I would try and remove the lever assy. And disconnect the cable to see if the lever moves and go from there.
Dave - - - -

 

I asked a moderator to move your thread to the LARGE TRUCK forum...as you'll get help from members that own like trucks.

Most members of this forum have pickups.

 

 

I have 83 F 800 with drive line parking brake. It has new linings , lengthend adjustment rod. It was pedal operated but I changed to overcenter with latch. I have fiddled with, will hold empty or loaded on flat ground but when loaded at 30,000 willnot hold on slite grade

 

Thank you, George.

 

That one little drum brake on the drive shaft isn't going to hold 30,000 lbs on a grade

 

I need the TRANS code printed on the Certification Label to post a pic of the parking brake system. Label glued to the left door face below the latch.

Pic: Drum brake parts (2 different types).

NOTE: Member asking question in post 3 is not the OP .. It's a

 

Shouldn't an F800 have air brakes??.., ?So why does it have a trans output shaft mounted drum brake??

 

They where available either way, I had a C800 with hydraulic brakes, a brother had a F800 with air.