Front disc brake seizes (right front)

[mf7lakes]

Been doing this since new (intermittent) and is most probably due to infrequent use. When it locks up, obviously pulls hard right, brake is smoking - to get to release, you gotta pour water on it or let it burn - and boy, does it make steam, enough to do a lobster.

Yep, and in time, there's gonna be cracks in the disc, leading to replacement.

My theory is the phenolic pistons get out of round and then stick/seize with brake use. The ones on my truck have been replaced twice before.

Any you guys had this problem ??

Wonder if there are any steel or even aluminum pistons in a caliper that would solve this ?

 

[ifrythings]

The phenolic piston doesn’t distort its shape from what I have found, what usually happens is rust forms between the dust boot and the piston seal and seizes the piston to cylinder. I’ve had very good results buying new seal kits and pistons and redoing them myself, you have to get all the rust out of the dust boot ridge and the seal ridge for it to last.

This is what I found on my 87 when the right side locked up on me once.

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and the caliper, that’s an aluminum piston with brake fluid sludge on it.

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[mf7lakes]

Thank you Ifry

 

[mf7lakes]

So, ordered new rotors, calipers, pads, and hoses. Rotor that got hot inspected and no cracks found.

Started small -- only replaced hoses to front calipers + new fluid and bled brakes - lubed pins.. Driven truck about 50 miles since then with numerous stops -- some really hard, most normal light stops -- system works like it should. No hint of lock ups at all.

Fluid was at least 7 years old, and brake lines probably 15 years. Have spare parts on hand for future beer disposal.

 

[Big Bart]

Although not sure of the cause, at times while towing, the front driver side brake sticks, heats up, and I can smell the brake pads. Pump the brakes a few times while driving and it seems to release again. I have new hoses, calipers, pads, rotors, hardware, bearings, and seals sitting on the shelf waiting for me to find some spare time. Did the master cylinder 18 months ago so will leave as is.

 

[Big Bart]

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So that is what 30 years of wear and tear looks like. It is surprising brakes don’t fail more often when you see something like that.

 

[u2slow]

These Ford twin-pistons like to stick and wear uneven because the mounting isn't super-secure. The 95+ brakes aren't nearly as troubling for this.

I had a rash of sticking calipers last year - dodge single pistons; 2 different styles. I guess it was my lucky year... not a common problem in the 20 years of wrenching on my own junk. They were all phenolic. I think there's something to that. Looked for steel-piston replacements, but not easy or cheap to find. Just got more cheapos again and so far so good.