My truck has a lot of free travel in the brake pedal. All new shoes and pads and system bled several times. Not mushy, just goes almost to floor. Stops good.
kk

 

Seems to me the brake booster would cause that, but not sure.
Anyone else have a clue?

 

Ah yes....Ford brakes and their infamous attributes. Try adjusting the rear shoes again.....not too tight but definitely not too loose. Usually free play in the pedal will go away with regular adjusting to the rears....(even though they use self adjusters!). Also, when you bled the brake system....did you do the ABS valve? (I don't know if your model has one but more than likely it does.) I recently did the brakes on my F250 and after all of the adjustments, it too had excessive travel...(and sponginess). Went back and re-did the rears, then actually by-passed the ABS valve altogether and the results were dramatic!!!! I left the ABS valve connected electrically as it is hooked to the computer and idiot light but bypassed the valve using some plumbing flare fittings. My brakes have NEVER been this good and I am the original owner to the truck! I recognize that eliminating the ABS valve system is not something that many people will agree with....but until you experience a firm pedal vs. before, have an open mind.

 

O.K. i bypassed the abs valve, and the brakes were great for about 2 days. now they kinda come and go. any more suggestions?? everything is new on this truck except the calipers. i've been doing this stuff for 30 years and never had this trouble. thanks for all the great advice.
k.k.

 

Sounds like your slowly eliminating possibilities. What I would probably do now is what I personally did before: Disconnect the rear brake hydraulic line from the master cylinder....and plug it with a flare plug. Then either try the brakes a few times while stopped or carefully drive it around the block or so. Remember, you will not have working rear brakes so the stopping action will be greatly reduced but you are only looking to see if the pedal remains firm when pushed. Note the feel. If the pedal is firm without the mushyness then the problem has to be in the rear system....if the problem is still present it's in the front system or the master cylinder / booster itself. I can't stress enough that the adjustment to the rear shoes is a critical element. You will definitely get excessive travel at the pedal even with the rears out of adjustment just a little.....make sure they are tight but not dragging.

If you get a firm pedal with the rear line disconnected and plugged at the master cylinder....you pretty much can eliminate the master cylinder / booster and front calipers from being the problem. You might take this opportunity to fully feel the action of the pedal when the engine is off versus when the engine is on providing the vacuum boost. Ford makes it a point to stress that if you push the pedal down with the engine off....then start the engine without taking your foot off the brake pedal.....the brake pedal will drop further. Many people confuse this as a spongy pedal but is actually the way the booster action is supposed to feel.

When bleeding the system, take extra care to remove all old brake fluid. Don't be cheap....keep pumping it through the system until it is clear out of each wheel and ensure that you have no bubbles. Don't let the master cylinder run dry when bleeding otherwise you are just creating more air / spongyness in the system. Also, when bleeding, it has been recommended to me not to pump the pedal agressively. Instead, slowly push the pedal to the floor....once....while opening the bleed valve. Then when the pedal reaches the floor, close the valve. Lift up on the pedal and again push down once....opening the valve, let the pedal go to the floor, closing the valve, releasing the pedal again. Do this many times but never pump the pedal. Some mechanics feel that pumping the pedal can stir up the fluid and make a foam.....which leads to more spongyness problems. Be gentle.

Good luck....let us know the outcome.

Greg

 

Another brake question: 93 F150, had a problem with right rear brake dragging, replaced all components, when replacing the drum it was very hard to go on, even with shoes fully compressed. Tried drum from other side, same thing. Checked axle, not bent. I forced the drum on, bled the system. Most of the time things seem fine, but occasionally when starting out I can feel the drag for a few revolutions. I don't use Ebrake so I don't think it's that. Any ideas? Thanks!

 

Regarding the right rear "tight" brake.....I assume that when you said all components were replaced....you also put new drums on???? or had them turned???? This is a strange problem but a recent problem I had with an old sports car may be of help. I was having periodic rear sticking problems as well. I did all the usual brake changes and adjustments but the problem persisted. It turned out to be a VERY clogged flex brake hose from the frame to the rear axle. What was happening was fluid pressure would transfer to the wheel cylinders when I pushed the brake pedal but the hose clog was acting like a check valve and not releasing the pressure when I let up on the brake pedal.....and hence the dragging brakes would occur. When it sat overnight, the pressure would eventually release and by morning the wheels again were free spinning. I know you are probably saying that you only have the problem on one side not both....but check it out....strange things do happen. Good luck. Let us know the results.

Greg

 

[updated:LAST EDITED ON 19-Mar-02 AT 05:35 PM (EST)]>Another brake question: 93 F150, had a problem with right
>rear brake dragging, replaced all components, when replacing
>the drum it was very hard to go on, even with shoes fully
>compressed. Tried drum from other side, same thing. Checked
>axle, not bent. I forced the drum on, bled the system. Most
>of the time things seem fine, but occasionally when starting
>out I can feel the drag for a few revolutions. I don't use
>Ebrake so I don't think it's that. Any ideas? Thanks!


Have to agree with kings51 on this one! I have not had this happen to my truck (Yet), but it did happen on my Minivan. You may not notice it to look at it, but sometimes the hose will collapse on the inside and cause the fluid to be trapped in the cylinder. This happend on the front disc brake on my Van and drove me crazy, until a friend of mine suggested loosening the hose fitting at the wheel cylinder and see what happens. Sure enough, the pads loosend up and for about $10.00 for a new hose, all was cured! And yes, they will partially collapse and cause intermittent problems like yours. Hope this helps!

Rick

 

At 124,000 miles I replaced the front rotors, front calipers,
rear drums, and wheel cylinders.
I wanted to start off fresh, for the next 124,000 miles.
I have the original master cylinder with 156,000 miles on it...
Gene

1996 F150 ext cab 4x4

 

kings51
you must be the king !!!!!
i bypassed the abs valve and it is the best thing that ever happened to ford truck brakes.
many thanks
kk

 

What kind of fittings and all did you use and how about some directions! I want to do the same thing. Thanks!

 

-X03 Ok, Ok.....I have gotten a lot of response from my ABS suggestio so here's the poop....I would recommend that the rest of the system be checked first....new fluid, check all seals and rear shoe adjustment. These all can and will affect your brakes dramatically.

The ABS valve is located under the drivers side cab on the inside of the frame. It will probably have a metal heat shield bolted over it. Remove the shield and you will see two steel lines going into it....one larger (inlet from master cylinder), one smaller (outlet to the rear shoes). Each line uses a flare (male) fitting however probably different sizes. Remove both fittings from the ABS valve and instead screw the male fittings from the lines into a new plumbing setup which you make using the following parts......

Attach two "90 degree flare (female) by 1/4 inch pipe thread(female)" fittings which are both hooked together using a "1/4 pipe thread (female) coupler". (These fittings form a kind of "U") These are all brass fittings available from the local auto shop....I believe the flares are American Standard....one is 1/4 flare, the other is 5/16" flare maybe 3/8", I can't be sure. Use teflon tape on the 1/4" pipe threads, not the flare threads.

Check for leaks, and rebleed the rear system carefully. Hopefully you will have the same results that I did.....The best brakes I ever had since I first bought the truck in 1989!

PS....you may consider purchasing solid flare plugs to seal off the open ports on the ABS valve. This keeps dirt out if you ever want to return to an ABS system, you can.....although God knows why you ever would!

Also, do not disconnect the electrical connector at the ABS valve....it hooks to the computer. If you do, you will get the ABS light always on....if you leave it attached...it will stay off.

Good luck....let me know the results. I have been fighting this for 13 years and am interested to hear more happy truckers using this idea.

Greg

 

i had this problem w/my 1996 e150(brake pedal falling to the floor)after a brake job. they replaced the mc. they told me that fluid was bypassing a bad seal in the mc and one day the brakes could fail. after they replaced it the mc brake pedal worked normally.

 

Hi guys.....

I recently posted a new response to a series I originally posted weeks ago re: Brake question for 1989 F250 4x4......just to move it to the front of the line again. For those who are interested in the ABS issues, its probably worth checking out. Look for my posting "Brake question for 1989 F250 4x4" from Kings51.

Thanks for the interest.

Greg