http://www.f150forum.com/f6/brake-pe...-150-a-157374/

Check your ABS HCU. My brake pedal continued to fade tot the floor as described in this thread. I replaced the ABS and all is well.

 

I checked a couple of trucks in a junkyard and they don't appear to have the same HCU that I have. All they had was what looked like a distribution box underneath the master cylinder attached to the power booster. Now, it seems this HCU is on trucks equipped with 4 wheel ABS, which I don't think my truck has. The hubs don't have any sensors or tone rings and there is only the rubber brake line and the 4x4 vacuum line running to each wheel.

 

Give me a call during the day @815 759 7832, easy to walk you through it then typing it out.

 

I think I have it figured out now... at any rate, I found a similar unit at another junkyard today. My part number is 1L34-2C346-BA and this one is -AA; I'm hoping its the same!

 

rear adjustment was bad thanks guys

 

You're welcome, and thanks for the update.

 

actually its like 80 percent right now but eh its better then petal going to the floor,

 

Yes and no. What that means, = it'll work, -perhaps not as well. AA = Original design. BA = Improved original design.

Letters @ part # end are revision order. The part has been change/improved upon. Since B comes after A.....

 

Rear adjustment was bad. Hmm... Self adjusters maybe? That's strange. No, you must be referring to the rod adjustment ? There's not to many parts here, which are you referring to?

Rod position is crucial, -I guess I'll go with that.

 

You gotta run the adjustment out when you do drums. Gotta drag the brake drum just a bit.. I always do a hardware kit cause if you dont the self adjusters never work..

 

I know lol. They do for a little while at first, after you service them. That opportunity presents itself with the over haul. At times, -the reverse break slam can do wonders.

Brembos's, Cardon STEEL piston calipers, Carquest Blues (and no, I didn't paint my brake shoes lol, -however, the factory (raybestes) did).

Stops on a dime, always, -loaded as well. Quality system and it costs just about the same as OEM replacement parts, which suck btw lol.

 

I rebuilt the rears on my truck 2 springs ago. while I was at it I swapped in a new ford traction lock and completely rebult the e-brake system and the rear discs calipers disc/e-brake drums. Had to find a new caliper bracket because the e-brake came undone. The rear discs on the 99+ plus can be a bigger hassle then full on drum if you dont maintain the e-brake. They get old and come undone.. I'm down to only 1 vehicle with the drum rears. My POS GMC 1 ton van. The brakes on that Van are impossible for 1 man to do alone.. Nasty springs.. Gotta have 4 hands.

 

Damn, sounds like you had some fun. The E-Brakes with the 98 were problematic as well. I replaced everything once and it lasted quite awhile. Started having problems once more and decided they weren't worth the hassle so I eliminated the system completely, even the pedal in the cab, - gone...

Never used them anyway which may have been the problem.

 

Update time! I replaced the ABS pump today. I decided to try that one first due to my symptoms and the fact that the ABS light has been on since I bought the truck (it was painted over). I had to re-flare three of the lines due to them breaking when the fittings came out and one of the lines from the master cylinder has to be replaced completely. The good news is that the ABS light is now gone.

Bad news is the brakes still don't work properly. They work a little better than they did before I started today; they work throughout the full pedal range but are quite soft. There is no fade when the pedal is held. I can pump the pedal hard when the truck is off but when I start it the pedal goes to the floor. Also, if I apply the pedal quickly, as in a panic stop, the brakes seem to grab quicker and firmer.

In summary, yes the ABS pump was bad and I now have a good replacement but it wasn't my only problem. I made sure to bleed the system at all corners and all connections are thight, no leaks anywhere. I suspect that perhaps my master cylinder is also failing/has failed. I didn't have the capability to plug the openings in the master cylinder today otherwise I would've tested it.

 

Unless you have a scan tool capable of bleeding the ABS take your truck down a dirt road and apply the brakes hard. Do this a few times to bleed/purge the ABS system. The ABS has to pulse for this to work so a little bit of speed is needed.