brakes that dont work very well and no one can fix
 

I have an 2003 f150 4x4, 5.4 king ranch.The brakes dont work very well, they dont go to the floor, but just dont do a whole lot when you step on them. 3 different mechanics have tried to fix it without luck. the last one said it need a anti lock part that costs 1200.oo for the part, i just took it home. any ideas? 148,000 miles on it and i have put brakes on it and had the rotors turned.

Rear brakes and rotor thickness determine pedal feel. As the rotors wear, the pedal begins to fall. If you got the rotors turned, they are under spec. I say that because I have never mic'ed a set that was within enough spec to even turn.

The ABS unit will usually not cuase a problem unless there is air in it, and the unit is inop. The better scan tools can run the ABS pump to assist in a bleed. This may be your problem. Or find some gravel and enguage it a few times & rebleed.

Honestly I have never heard of brake problems that can;t be solved. Find a mechanic that is good. There were a few chrysler minivans that used the abs system to also provide pedal assist. Those were about the only brake problems that could not be diagnosed, even by the dealers.

Every so often some one comes in with this issue.
I fail to see why it's such an issue with a power brake cylinder, a master cylinder, two front calipers and two rears and 4 discs.
The ABS usually has little to do with it.
What has been done, what has been replaced etc.?
Without any indication we are all guessing.
I have been through 3 sets of pads, one set of discs in 187,000 miles without an issue.
I will say however the pads you use make a great difference for braking quality.
I found this out while towing gross loadings over 12,000 lbs. where stopping was a major concern.
Always use the same pads front and rear to maintan some semblence of friction balance independent of any issues so it does not add to the problem that may be present..
If you can't stop your truck with no load, something is very wrong.
Good luck.

I had this problem with my IROC years ago and a Saturn. Both were the fault of inferior pads, both bought at autozone.
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I'm taking kind of a wild guess here but flush and change your brake fluid. It is the most commonly "overlooked" fluid change I have seen. I say that assuming you had a 4 wheel brake job, if not look at your rears. This is where third party gets complicated, I would guess there is over 1000
people on this forum who could drive your rig around the block, jack it up for a quick look and fix it in a half hour, could be something as simple as your front pads are glazed becuase some azzhat didn't clean the rotors properly. Any decent shop should be able to get you squared away for a reasonable price.

Side note:NEVER EVER tell a garage that you have brought this to *# other garages to have this problem fixed unless you have on your please rape me panties:-wink

I have a similar problem with my 1999 F150. I push the pedal for ever until I stop. I've concluded the drum brakes in the rear are not "self adjusting" as when I have them adjusted they work fine for a while, then slowly return to the sloppy state. Any ideas on this one?

George

I just went through this issue with my new to me f150 in november. The brakes were all new in the previous 6 months but braking was poor. The problem turned out to be the cable guide for the brake adjuster lever. Here's a pic.
http://i42.photobucket.com/albums/e3...rame/008-1.jpg
http://i42.photobucket.com/albums/e3...gframe/004.jpg
This was the reason the shoes kept backing off, but when looking at them assembled, it was difficult to see anything out of the ordinary.

doesnt the 2003 -150 have 4 wheel disk brakes? I found if the brakes seem to not want to stop the truck is because the rotors and pads have glazed up and there is no bite to the two . cause is high heat / poor pad quality. the pedal is firm , but have to do alot of pressure on the peddle to get any action from the brakes.. needs better quality pads and turn or replace rotors. try not to over heat brakes in future ..

This owner has to start all over again and inspect each area to be sure and uncover the issue.
I once had Bendx Titaniums of commercial quality that were the best I ever had but they disappeared from the market place.
1. What is the Pad situation? You need to use the highest grade offered, not the cheapest in cost.
2. What is the rotor situation?
3. If the master has been changed, is the push rod adjusted to the correct length?
4. Has all 4 corners been bled into a cup so you can see when the fluid comes out without any air in it?
That means a hose into the fluid cup so air does not reverse and go back into the caliper or use a vacuum hand pump to draw the fluid.
5. Is the power unit good, getting vacuum and the check valve working.
Unless someone goes over all these items you have a dangerous truck on the road to yourself and others, if it is as bad as you indicate.
On a 4 wheel disc the EMG has nothing to do with the hydraulic operstion because they are seperate and mechanical.
Normally ABS has little to do either because it does not come into play unless a wheel speed is sensed as spiinning faster or slower than the others.
This thread has given enough info for you to solve the problem but someone has to do it.
Good luck.

1/ all replaced. Same problem old ones didn't look that bad . 2 rotors new. Same problem then too.3/ length was checked and matched to factory. 4 bled all 4 over and over. No air. 5. Has to be in here somewhere

If nothing is found then you have to have a vacuum assist problem.
I'm sure you must have cruise control.
Take the plug off the CC knock-off switch and put a meter on the contacts.
It should show a short.
When the brakes are applied it should go open from the pressure.
A simple check but one to do non-the-less to see if there is at least enough pressure to make it open.
Pull vacuum with a hand pump on the vacuum assist to see if it holds vacuum through the check valve.
The metal line from the back of the intake to the vaccum assist hose, is it broken or bent closed somewhere out of sight?
You have to begin to go back to basics to find the issue because your liable if an accident occurs from not being able to stop the truck with reasonable effort and an inspection station should not let it go because they can also be liable passing the inspection with a known fault.
.
I have built race cars from the ground up and put brake systems in from scratch and don't have this kind of problem.
I have converted front drum to disc on cars and put manuel brake bias control to the rear line set under road test not to lock up the rear brakes.
.
If you have to, put a 0 to 1000 psi gage on the CC switch port and with the motor running see how much pressure is developed with normal braking effort.
You have to go throught these gryrations to find the cause when normal service dosen't find the issue.
Good luck.

You still haven't said anything about the quality/brand of your replacement pads&rotors. 20$ brake pads work like a 20$ salvage yard starter, kind of..., but not like it should.

oreillys best line of parts is what i always buy. and im not asking for legal advice thanks though. , liable is liable.

I have no idea where that comment came from:-lamesign. No one in this thread has mentioned liability other than you. Don't get mad at me for trying to help, maybe you sould trade your truck in for a prius.:-X0A6

Possible Solution for Spongy Brake Problem
 

I know this is an old post but, I recently bought a 2003 F-150 that formerly had the problem I think that is being described in this post. The former owner discovered that the front braided brake lines were actually ballooning out somewhat. This gave the brakes a spongy feel. Replacing the lines solved the problem.