Scammell explorer rear brakes help needed setting up

[rbrtcrowther]

Hi chaps :-) Took the scammell for another test run today after sorting all the hub seals ect and think the brakes could be just a tad better. I have adjusted the rear shoes as it says in the book and there is plenty of meat left on the shoes themselves. The truck pulls up nice an straight however i can bottom the brake pedel out with my size 12. I feel here lies the problem.

The lower arms on the vertical gear shafts on the walking beams are touching the gear case in the little resess for them is this correct?

How much slack shoud be in the overcomplicated rear brake cables the long ones on mine can be moved up and down about 6". Are the cables supposed to be tight and pulling the vertical spindel arms slightly? If this was the case i would have thought adjusting one wheel station would tighten all the other rear brakes through the compensator linkages.

Is slack required in the linkages to allow the walking beams to move without pulling the brakes on.

I am pretty sure the vertical spindels are supposed it be touching the back of the beams to allow the brakes to be adjusted its just the slack in the cables that is the problem. The book says nothiing about setting it all up and most of the adjustable links have the same thread each end :nut:

just another point when pulling the main rod from the servo i can here air moving in the valves is this normal too?

 

Sorry for all the questions but if anyone has set one up from scratch a step by step guide would be very helpfull:undecided:

Thanks

[julezee001]

I had a quick look at the linkage on the selection at work. All the vertical spindals have about an inch gap between the back of the bottom lever and the final drive casing. This is with the shoes properly adjusted and the brake pulled on. I had relatively little time, so I didn't have a look with the brakes off.

 

The place to start is adjusting all the shoes until they are all about to bind, using the individual adjusting rods. There is then a little adjustment in various rods between the pivots bolted to the rear differential, and the pedal itself. I think I adjusted the long rod between the brake master cylinder, and the actuator last, and that brought my pedal right up.

 

I'll try to have a more detailed look in the next few days and take some more photos if that would help?

 

Jules

[rbrtcrowther]

I'll have a look when i have a couple of hours. I can make a note of how it is now and look at adjusting the slack out of it. my brake pedal has at least 6" travel with the air built up.