Hey guys,

I've spent the last couple of weeks rebuilding the brakes on my 1992 f150 2wd. Things I've replaced:

• Both front calipers
• Front pads
• Front brake lines and hoses (rears were replaced by previous owner)
• Rear Shoes
• Rear cylinders
• All rear hardware
• All emergency lines

The Master Cylinder did go completely dry when changing the rear lines. I wasn't able to stop the fluid in time.

I replaced the fronts on week 1 and the brake pedal felt fine after. After replacing the rear brakes on week 2 the spongy brake came into the scene. I've bleed the brakes properly several times and the master cylinder (Bench) but only on the last attempt did I try bleeding the ABS module. I did not use a scan tool and I have no access to one.

Ever since, the pedal activates all of the brakes but goes too far to the floor for comfort. The ABS light comes on when the truck warms up then goes away after 5-10 minutes of driving.

Does anyone know of a place that rents the scan tool? Or if I have any other options? All advice is appreciated!

 

A scan tool will not read ABS codes. Some great info from Steve83: RABS Flashout Procedure and Code Chart

 

Oh sorry, I meant the tool that activates the ABS unit so you can bleed it properly

 

Personally I have never done that before or aware it had to be activated to bleed. A Bronco with 4WABS, yes. An F-series with RABS, no.

 

I would guess the rear brake shoes are not adjusted up tight enough. It can be real tricky to get them properly adjusted. Something you might try, find a place away from traffic and back up hitting the brake pedal and letting it up. Do this for a while and see if the brake pedal comes up. I have done this before and it worked.

 

did you replace the RABS module?

do you have a RABS module?

should be be up near the front of the cab underneath the drivers side floor pan, on the frame.

has a bleeder screw like everything else.

also, check all you brake lines and make sure none have 'pin hole' size holes in them leaking brake fluid.

not a bad idea to recheck the wheel cylinders, usually a good idea to replace both, if you replace one, replace them in pairs.

make sure no leaks around the rubber lines, sometimes its hard to get aftermarket lines to seal to the front calipers.

there is also a rubber line on the back of the frame, underneath the truck bed, on the drivers side, that connects the brake lines on the rear diff.

I dont think a scan tool in this case is going to help,

if you have a 'haynes' or similar manual, just read through the 'brakes troubleshooting' section.

 

I do have a RABS module and I have not changed it. I've replaced the wheel cylinders on both sides and all of the steel line and hoses are new. I've bleed All wheels and the RABS module following the Haynes manual and have no air coming from them. I did not know about the rubber line that leads to the rear differential though.

I'll give that backing up trick a shot! I thought I got those brakes as close to the drum as I could but maybe i'm wrong.

 

My guess is that the RABS module has failed. My truck had been sitting for eight years. I replaced all the lines and hoses because of rust through and age. I could not get a firm pedal so I figured the master cylinder had gone bad. It was only after replacing the RABS module that I had a firm pedal.

 

It sucks because I had a firm pedal before replacing the rear shoes and hardware. Probably should have tried harder to prevent the master cylinder from emptying...

 

I still think your rear shoes aren't set up tight enough. It gets harder to judge them with the drive train and all dragging as you turn the wheel. The trick is to tighten the shoe until you have a heavy drag and then back it off just enough to free most of the drag. You will still still hear the shoe and drum hitting some as it comes around.

You may have to use a thin screwdriver to hold the self adjuster tang back as you back it off after tightening to get a heavy drag.

Those things seem to intimidate me about every time.

 

I am definitely going to work on adjusting the rear shoes. It's a very good possibility.

 

The ABS light is now almost always off but when it does come on it's usually just after turning off ( on the initial start up). Havent had a chance to adjust the shoes yet. It's been pretty rainy here

 

Why ignore the warning light? Some great info from Steve83: RABS Flashout Procedure and Code Chart

 

The star tooth adjuster is designed to adjust when there is to much play between the shoe and the drum thus the star tooth adjuster will move a click when stopping in reverse and tighten until it can not go any more. After the back shoes are manually adjusted until they just touch then back off; drive to a safe place to perform the next step. Now check your rear view for all clear and drive in reverse, give it moderate gas quickly and hit the brakes hard. Do this with the window down, I heard mine adjuster click several times until I heard no more clicking. The rear brakes are now adjusted.

 

The self-adjusters will never self adjust, if the initial setup adjustment isn't performed manually. Ever.

They (shoes) need to be run up just as tight as they can against the drum with the adjusters manually and the pedal depressed several times to center and take up all the slack in the components. They should be bled while in this configuration too.

Then back the adjusters off several clicks so the wheel will turn, but still dragging. If they are set too loose there isn't enough for the shoes to grip on the drum in reverse, this is what actuates the self-adjusters, you can back up all the way to Florida and stomp on the brakes the whole time and they won't tighten up. Just a few clicks too loose will contribute to a low squishy pedal, too.