WAY off subject but...

[GaryBeu]

I know this is the BCF but the real auto experts live here. One of my front disc brakes on my 1995 Ford F-250 4wd is apparently binding all of a sudden. Truck pulls to the left when driving and the wheel is very hot. Brakes were redone 15,000 miles ago. What would be the appropriate method of checking the problem? Thanks

Gary

 

[Dave_W]

Were the calipers rebuilt with new seals and pistons when the brakes were redone? If not, then oftentimes later down the road the pistons will seize up in the caliper. Some of those used composite pistons instead of metal and they tend to expand and bind and not return properly. If they're metal pistons, then rust, etc. causes the same problem.

That seems to be the most common problem with them. Do both if that's it because the other is probably not far behind

 

[Bob Claffie]

Not familiar with Ford big trucks but, if it has a single piston system (pistons pushing from only one side) it's possible that the caliper is hanging up in the caliper frame. The frame would pull in the pad opposite the piston and not release. Bob

 

[Deleted member 8987]

At 15K, a caliper hanging in the slide will show more wear on the piston side pad.
Look.
Also, was not aware Ford had gone to composite pistons. Must be weight/cost, as the disaster of the Chrysler composite pistons on the 70's and 80's that swelled up and locked should have taught everybody in the industry a lesson. You could buy replacement stainless or plated pistons to fix it.

 

[Dave_W]

Unfortunately I know this first hand since my '95 van, my '97 motorhome, and my son's 93 Escort and earlier his '87 Escort all had this problem at one time or another. All had composite pistons. Buying a rebuilt caliper with steel pistons was the best fix in all cases. To paraphrase the Beatles, "All you really need is $"

 

[GaryBeu]

Thanks guys. I don't know if the pistons are composite or what. We replaced them with "new" calipers when the work was done. I'll be looking at it later today.

 

[Scott_Hower]

Floating caliper or fixed? If floating, check the guide pins and ensure they are not bent and the caliper floats freely. Some mfgs suggest lube, some dry but polished. Thats the first thing I'd check.

I polish mine in the drill press and use a *tiny* smear of wheel bearing grease.

 

[emmett1010]

make sure that the caliper brake hose isn't twisted one revolution.
Emmett

 

[PAUL161]

OK, let me throw in a ringer, as your truck is old enough! Check your front flex lines, actually I would replace them anyway. I had this happen twice. The flex line on one had a steel clamp that held it from moving, the clamp rusted between it and the hose so much, it actually restricted the fluid from returning back after brakes were applied. The other one went bad when the rubber inside broke loose due to age and caused a valving effect, allowing the fluid to move only one way. Regardless of what ever is wrong, I would replace these two lines. JMHO and experience. PJ

 

[aeronca65t]

Yes. Like Paul, I've had those flex lines act like a one-way check valve, preventing fluid from coming back out of caliper.

In my case, the flex line had come apart internally. It's a good idea to change them if they're older.

 

[jsfbond]

On the parts counter we see this all the time, mostly after the customer has already replaced the caliper/wheel cylinder. When you ask them if the checked the hoses, it amazes us that the test for this, is the same as for battery cables. You just grab it,wiggle it back and forth, and............its good!

 

[GaryBeu]

Thanks for all of the suggestions. It's been raining so hard here (I have to work outdoors) that I haven't gotten anywhere yet. Hopefully, tomorrow.

 

[GaryBeu]

Well, I took the caliper off and the lower piston is frozen. The rubber seal around it is gone so I guess water and road salt did it in. I'mm gonna replace the flex hoses on both sides "just because I'm there". Thanks again to everyone.