Allright so I've got a problem that I can not figure out at all. Started about 2 days ago, The brake pedal started getting loose and about 12 hours later of driving I could push the pedal all the way to the floor. Also for some reason the trailer brake controller reads 0.0 when I'm on the brakes and it blinks on and off. Normally all it does is the . comes up in the middle and doesn't show any numbers unless of course you have a trailer hooked up.

I pulled all 4 wheels off tonight (after I bought all new brake pads). However all the pads have about 75% life left. There are no visible leaks from any of the lines and the master cylinder is completely full.

The brakes are working fine except if you get the pedal about half way down they will lock up and you can feel the abs, yet the light doesn't come on. Also when you get it down to that point the pedal wants to spring back into place.

I can't think of anything to check or do. I can flush the system but I don't really want to waste the time if it is electrical problem or something like that.

Any help will be greatly appreciated.

Thanks,

 

...Nothing?

 

It's pretty odd that you haven't found a leak....because that's what it sounds like.

I'm wondering if there's a problem with your ABS unit. I just don't have any experience with the ABS units so I'm hesitant to advise what to check next.

Let's hope one of the pros chime in here soon.

Joe

 

I don't understand:

First you say you can push the pedal to the floor but then you say the brakes work fine but they will lock up. Also, I have never experienced the pedal wanting to spring back in place. Can you explain these things a little differently (or maybe I am just not reading your post correctly).

The pedal to the floor sure sounds like you may have a leak, but a bad hose could produce a mushy feel.

 

Allright

It's pretty difficult to explain without physically feeling it but I'll try to explain better

If you are using the brakes normally you would never know that there is a problem since the pedal doesn't want to go to the floor with normal pressure applied to it. However if you press on the pedal with significant pressure you can touch the floor board. Once you get the pedal about half way down it feels like there is no pressure holding onto it and it goes to the floorboard with ease. Once you get it there though it will "spring" back into place not the way it would if you had a leak where it would "slowly" return to the normal position.

Also on our trucks once you lock up the brakes the abs light should come on to show you that it is working, correct? Or does it only come on if there is a problem with the abs? Either way it isn't coming on period.

The thing that puzzles me the most is the trailer brake controller blinking on and off.

I hooked up my trailer today and the draw-tite was working fine, and it reads normal yet the brake pedal still has the same feel it does without a trailer hooked up.

Hope that helped?

Also bismic I do not see how it could possibly be a leak since I havn't lost a drop of brake fluid out of the reservoir. Also the pedal doesn't feel "mushy" at all it feels perfectly normal except the fact of course that you can push the pedal to the floorboard, but I appreciate the response thank you.

Edit - I used the word significant in the second paragraph. That isn't the correct word. I don't want to say its easy to do but it certainly isn't difficult.

 

quote..... "Also on our trucks once you lock up the brakes the abs light should come on to show you that it is working, correct? Or does it only come on if there is a problem with the abs? Either way it isn't coming on period. "


I don't have a clue to solve your problem, liv, but maybe your ABS light is burned out.

 

Possible that the mastercylinder has an internal leak??? Also, as far as I know, the ABS light only comes on at key on OR if you have a problem and it's not working correctly.

 

The spring or bouncing feeling in your pedal is the ABS functioning. Kind of feels like a reverse tug of war going on.

I don't think the pedal should easily drop to the floor, but compared to non-abs brakes there is a point where the pedal feels soft before it starts bouncing. I believe the ABS light only comes on if there is a problem with the system. When you first turn your key on (before you start) does the ABS light up?

The brake controller problem sounds like a bad connection. Check your ground. Also take your plugs apart and look for corrosion where the wires go into the plug.

Good Luck.

 

Sounds to me like you need a new master cylinder.

The ABS light should come on when the ABS has a problem. On some older trucks it also comes on when the master cylinder is getting low on fluid.

 

The ABS light does come on at start up.

I do not see how it could be something wrong with the master cylinder but I guess I can just give it a month like this to see if it gets progressively worse and go from there.

All the wires for the trailer brake controller are inside the cab and have been checked so rule that out.

I guess I'm lost too. I'll repost here in a month or so to see if I get it figured out. Otherwise I guess everyone who drives my truck will just think there is something very wrong with it :\

 

I said before that I can feel the ABS working while the brake pedal is pressed hard while moving(or sliding lots of ice here lately), but I can touch the floorboard while I am at a dead stop and/or in park.

 

It's the master cylinder. My 03 F250 SD had the same kind of brake pedal as you are explaining. It drove me crazy checking calipers and such. I pulled the master cylinder to change it and found that it was leaking out the backside seal at the push rod. I believe I picked up a replacement at Advance and it came with a lifetime warranty.

 

I was referring to the plug in the back of your truck. It's possible to get corrosion inside the plug where the wires connect. This can cause a short and make your brake box display the 0.0.

 

My 86 and 89 ford had a problem that can be described like the one on this forum. I'm with redford, the master cylinder sounds like the culprit, and it was on my older fords too!

 

I had a similar problem with my 04 F350, the brakes and lights work great, but I was having problems moving the shifter out of Park. Sometimes it would work fine, at other times I would need to stand on the pedal to release the safety switch. The pedal would go to the floor, so I agree that is possible and no leaks. The solution to this problem was to change the switch that is hidden well up on the stearing column. Since that was done, no further problems to report.