For years my rear brakes on my 1989 Ford F350 XLT dual wheel truck have stuck to the point where they tear up and i am left to drive with only front brakes. This time around fixing them, i replace everything. I installed a new brake booster, new drums, new brake shoes, new master cylinder, two new front brake calibers, new front brake pads, two new rear wheel cylinders. I had all of this done and my rear brakes still stick at times. I can feel them holding the truck back. When i stop, you can smell the brakes burning. One thing i have noticed when my rear brakes are slightly sticking is that the brake pedal becomes very hard. I don't know of anything else i can change to stop this problem. Can anyone here shed some light on this problem, it is really driving me up the wall. I let my mechanic fix my brakes, i am thinking that maybe i should take the truck to a brake specialist.

 

A good brake specialist is in order.

You may have what others here have described where a hose comes apart inside and acts as pressure check, causing brakes to drag. Or maybe there is an e-brake issue with cable routing. Is there a propotioning valve in this system that adjusts the rear brakes for load/no load?

I'd bite the bullet before all those new parts are worn out.

 

Moved to proper forum.

 

Yeah, i am just gonna try to find a good brake man. I have no idea about how to trouble shoot brakes. All i know is how to swap out parts. This is very aggravating i can tell you that.

 

I have seen this situation with the Ford trucks time after time, including one of my own. You have three possibilities causing the problem. The easiest one is first.

Remove the wheels and drums. Take a course file and file down the leading edge of the shoes, the front shoe on the top and the rear shoe on the bottom, both sides.

Then while the drums are off, carefully have someone cycle the brakes. Make sure that both sides of the cylinder moves. If not, the cylinders are sticking. Replace them, do not repair. Also, while here, replace the 350 springs with a set from a 550, they are a lot stronger and will return faster. At this point, lube the emergency brake cables. DO NOT USE GRAPHITE. There is a special lube at NAPA for this. IT does not melt under high temps. Don't want lubricant on brake shoes. I have seen some idiots at Ford do this.

If all these items are free and moving easily, the next on the list is to just replace all the rubber lines on the rear. Your truck is an '89 model. Fifteen years is a lot of wear and tear. This is only a safety precaution.

After all of this, if the problem still exist, the only thing left is the proportional valve and the master cylinder. Both will cause excessive pressure in the rear wheel brakes. I did forget the antilock, but usually a complete line flush will clear that item. I hope this helps you find your problem.

 

I am gonna replace the rubber lines first, as i stated, i just put ALL new brake hardware on this truck, it has not even been on the truck a week yet. The only thing old still on the truck are the brake lines and hoses.

 

You underestimate the impact that a gummed up prop valve or ABS valve can have on brakes - I have seen this exact same problem on a lot of ford trucks, and more often than not it's one of these two items.

What happens is when you press the brake pedal and the rear brakes engage, one of the valve is gummed up and doesn't allow the shoes to retract as they should. They stay mostly engaged. Then you hit the brakes again, and they re-engage. This continues until the shoes wear down. This sounds to me like the problems the poster is having.

 

Andym, right you are.

I do recall the ABS causing problems on my '96. It took me a while to figure that out. It would only happen once in a while. One night I was getting more than the usual ABS chatter (wet roads and cold temps), then the warning light flickered on then off. It did not set a code. The next day, I had an extremely hard sensitive brake pedal.

I do not remember what the Ford Tech told me to use (I think 100% alcohol), but I flushed the brake system. All sorts of black gooey gunk came out of the system behind the ABS. After the cleanout and rebleed, the problem never returned, but the brakes were more firm and much more sensitive. Man, I wish I could remember what he told me to use.

But with the age on 4Rings truck, I would suggest replacing the rear and both front rubber brake lines. They are not that expensive and great insurance. I would also use OEM, not the "tiwan" junk offered by the local jobbers parts stores, unless he went to stainless braided lines.

 

I've never heard of flushing a brake system with anything other than brake fluid - maybe you're onto something! I'd be very interested in knowing what he recommended to use, if you're able to dust it off.

 

Andym, I wish I could remember, that was five years ago.

I remember he especially told me to not let any of it get into the calipers or wheel cylinders and to make sure that I refilled the master cylinder after each flush and to push it dry. I want to say alcohol, maybe it was MEK, or a mixture of both, dang I just cannot remember.

I traded the faithful old girl off for the '01 SD and my repair notebook went with it. When I get home, I will have a look around and see if the container I used is still there. I always mark the containers at what I used them for. Man, some of them have quite a listing on them.

 

Check the shaft that your brake pedal hangs on.
I had a Dodge van that did the same thing, and I found that the shaft running thru the pedal assembly was rusted and when the brakes were applied, they did not let off.

 

That proportioning valve has given me some optimism, i am gonna look into that immediately.

 

Andy: I cannot believe it. I found the can. After using the old nose sniffer on it (BUZZZZZZZZZZZZZZ), it is a mix of Alcohol and MEK. I guess the MEK dissolves the deposits and the alcohol flushes the MEK and debris out. The mixture was marked 75/25. 75% Alcohol. I have a few special notes written on the can:

1.) Do not let Mix set in system. It will destroy rubber seals. Open rear bleeders and gravity feed system with minor stroking of pedal to force Mix through.

2.) Make sure that at least one quart of brake fluid is used in each section of the Master Cylinder (two quarts needed) after doing the flush.

2.) Do not power flush, MEK is explosive (flashpoint is lower than gasoline, 92 degrees)

3.) Do not backflush.

4.) Gravity Bleed the rear brakes first, leaving the fronts open. This is to flush the alcohol/MEK out. Then power bleed the rear with the brake pedal (engine off).

5.) Gravity Bleed the front brakes, then power bleed (engine off).

6.) Use fluid marked DOT 3, perferred is DOT 4, DO NOT USE DOT 5. DOT 5 will destroy the antilock system.

A special note. Get your alcohol from a paint supply store, not off of the Walley World Shelf. It has to be 100% (like grain alcohol -- DO NOT USE). Alcohol in stores usually has water in it to delute it.

I know BMW and GM states that no Alcohol is to be used in flush. They do not specify a reason why.

This information came from a "Old Timer FORD Mechanic." I believe he road on the boat with Moses (That Old).

I hope this helps.