Hi guys,

Please don't bump this to the superduty forum. I tried posting there last week. Definitely got some help but no definite answers.

In the last 2 yrs and 20K mi, I have had 6-7 stuck smoking calipers. Front and rear calipers, rotors, pads and brake lines have been replaced (all with Ford equipment). The new front caliper locked after just under two yrs, the rear after 1 yr. Every different position has locked at one time or another. I don't tow anything. I drive it almost everyday. No hard braking - it's flat here in FL. The left rear just locked again today - it was removed and lubed just 3mo ago when a front caliper was replaced on warranty (the shop's warranty, not Ford). I know the owner of the shop - he is good and honest and takes good care of me.

Consensus from my last posting was to try steel piston calipers - these are apparently expensive. Any other thoughts. I have been almost two yrs without any engine issues and I would be singing the truck's praises if I could just get this brake issue sorted out for good.

Thanks for any help and thoughts - Dan

 

The only thing I can think of is salt spray or water since your in Florida. Have had my truck 7 years now and zero brake problems. Just one wheel bearing. Upgraded the dust shields.

 

Salt spray has been the main diagnosis locally - I do live close to the beach, but two neighbors with similar trucks don't seem to have the problem. Also a number of guys from the midwest have had trouble too, although usually with hauling heavy loads. They were all heavily lubed in June too - ????

 

Ok, for the sake of thinking "outside the box" I'll risk saying something stupid (<--Grin).

Does it have factory wheels on it? Does the truck have adjustable power pedals?

I have had a couple of cars have a caliper hang up after the old one was replaced. It turned out to be the flex line at the wheel. They looked ok from the outside but apparently were separating inside and a small "flap" of rubber inside the line kept the fluid/pressure from reversing when the pedal was released, keeping pressure on the caliper all the time. There are a couple of places on your truck where the line is flexible AND common to the front or rear wheels, but not both. It would be unlikely all four wheel lines were bad or even two (to account for front and rears being a problem).

Along the lines of what all four wheels have in common are the hydroboost system, the ABS system, and the master cylinder/pedal assy. Maybe the hydroboost system is keeping slight pressure on the master cylinder, or there is an issue with the brake pedal and linkage doing the same thing.

I haven't had my master cylinder off but some vehicles have an adjustable pushrods between the pedal linkage and the plunger on the back of the master cylinder. If it is adjustable, maybe it isn't set up right.

The ABS system has electronic controls and can be tested/diagnosed with a computer. It may be possible it's having a subtle problem that's not turning on the dash light.

 

Good call on the flex line Rusty. I have seen that and forgot all about it. I have put all S.S. flex lines on my 69 Mustang.

 

Rusty,

They are stock 20" wheels. I don't think I have adjustable pedals - if I do, I have never used them. I have been wondering if another line might have become problematic. I believed they checked all the other lines. When I take it back in later this week I am going to have them check everything.

The cab was off 3 yrs ago for the head gaskets - the problem did start shortly after that. That is about the only time I think something could have gotten damaged or tweaked. - Dan

 

CJ - the flex lines at the wheels were all replaced - only the central lines are old. Does any make SS lines for our trucks? I am ready to switch. - Dan

 

try oem parts. ford calipers are something like $85 ea and come with a 12/12 warranty. havent had any issues with them.

 

the calipers were all Ford reman's - the shop warrantied them for 2 yrs probably because they felt bad for me. I was thinking of trying ssbrakes.com - stainless steel pistons, 6 piston calipers - they are pricey though.

 

since you have replaced calipers both front and rear i would guess your problem is master cylinder related as rusty suggestd the rod between master cyl may be to long or needs to be adjusted but my bet is the compensating port in master cylinder is pluged both the rod and hanging pedal or riding the brake and pluged compensating port give same symptems

 

Could be where to start...

 

Can you guys give me any advice on how to trouble shoot the other possibilities? Should I try replacing the master cylinder with a full flush of all the lines?

I try doing repairs here and there but my experience is much less than most on this forum. My brake work experience so far has been limited to pads and rotors. I am certainly willing and eager to try to get this fixed. Thanks for the help so far - Dan

 

I would at least suggest completly flushing the system.
start from the right rear, left rear, right front, left front.

toi replace the master cyclinder undo the line then undo the 2 15mm nuts thaty hold it to the hydroboost.
bench bleed the new unit then install both nuts first then hook up lines.

 

Brake system should be flushed every 2 to 3 years if you haven't done it. They can freeze up just as easily from the inside as the outside.

 

I have had the stuck caliper too. It was a relatively new Ford reman purchased from the dealer.

Even after complete disassembly and reassembly, relubed the slide pins with proper hi-temp brake lube (which weren't stuck), made sure I burbed the boots on the pins, tried without burping. Tried it every which way I could think of.

After 3 reassemblies it was still sticking (not opening back up) and I was going crazy. I then disconnected the flex brake line from the caliper and flushed it into a clear container so I could examine the fluid coming out. At the stuck front wheel I got tiny tiny flecks of black something in the fluid. I then disconnected the hard brake line from the flex line at the frame and flushed again. I got clear fluid all the time.

I went to NAPA and replaced that flex line and connector for ~$19. Reassembled everything and now no issues.

I had heard about the flap in the line so I figured that was what was possibly happening ... it was acting like a one way valve.

Other possibility was that when I was flushing my brake fluid on that previous brake job, I didn't get all the old out of the reservoir with the hand pump and maybe I picked up some dirt and flushed it through the line to a choke point.

End result, everything has been working fine after swapping that flex line (~$19 at NAPA).