im working on a 1997 ford F350 xlt 4x4 7.3l single rear wheel.... this truck is used mainly to plow and salt i started on the front brakes and now its leading the full soup to nuts job. i have a couple questions

1. what does the abs modulator/hydaulic unit on the frame below the master cylinder do and do i need it ???? its super rusty, not leaking but not sure if its working . my friend said the ABS light is on if that makes sense but batteries are disconnected now so cant check.

2. why does abs modulator/hydaulic have a bleeder screw on it and what would be the procedure to bleed the rear with this unit and the wheel cylinders if i even need still need this ?


3. this line has been replaced before and it has all 3/16" line on it . is it suppose to have 1/4" line from master to ABS modulator and 1/4" from ABS modulator to rear rubber flex line???????

4.anyone have a link to the redoing the rear drum brake system+ E-brake stuff with all torque specs? single rear wheel truck

 

All it does is control the RABBS system.

if you loose oil in the rear brakes, you have to bleed it, it will have air in it and you'll never get the rear brakes bled without bleeding the module as well.

Procedure is kinda a pita cause you cannot vacuum bleed it either.

Bleed rabs.
bleed rear brakes as normal
bleed rabs
bleed rear brakes as normal

you usually have to bleed it 2 times.
took me 3.


Drum brakes on these trucks require virtually no tools.
A pair of needle nose pliars is all you really need.

Sometimes a long heavy flat head is handy for the one spring, it can be a pita some days.

if your bleeding the rear brakes you dont have any pressure on the cylinder on the rear brakes so the shoes compress in really easy and you can put the big spring in really easy.

 

i can just bypass this right and fun a 3/16" line from master cylinder to rear flex line right ?

 

Some fellas just run a short piece of steel line between the two RABS valve fittings to bypass it.