I had the same problem on my 92 F150. My fronts would lock up with any moisture in the air. What I did,was pick up a new set of front pads. Not the cheapies or the most expensive ones. The high end ones are too hard for around town driving. I pulled the rotors and cleaned the rust from the outer edge where the pad does not touch. I then took my random orbit sander with 220 grit paper and lightly knocked off the glaze. When installing new pads on old rotors, I like to put a bevel on the outer edge of the pads. 45% and about a 1/4 in. deep. I find this helps seat them faster and in most cases I will not get any brake squeal. I then put good break grease on the calipers where they slide on the mount. 35K and not a lock up yet. Ford trucks have a problem with break dust build up on rear breaks. I blow them out once a year and grease hardware. Never a problem with my back breaks in five years since I started doing this.
Hope this helps.

 

I've NEVER, but NEVER had a problem with the rear brakes, other than the hair raising experience of the RABS doing it's job one time. Wasn't a problem with the rear brakes then, just the hole I pinched in the upholstery when I slid through an intersection because of oil on the road on a rainy day. Fronts locked, and the right rear was in the oil, it sounded like the truck was coming apart. Tires never made a sound because of the really nice lube job someone left on the pavement. I pulled the rear drums when I did the front pads, and they were very clean for the mileage on them. This is the second time in the life of the truck that I can remember them being off. First time, I pulled the little metal keeper off that the factory puts on the wheel studs to hold the drum on until a wheel is mounted. That time was just to check the brakes and see how they were holding up.

I probably should have done like you did, and at least scratched the glaze to prevent the squealing. Like you, I also bought the middle grade pads, but made sure they were the ceramic/metallic OE type pads. I put a full tube of the caliper lube on the backs of both pads on each wheel. It isn't the pads squeaking on the calipers, it's the pads moaning against the rotors when I've just used the brakes, and usually when starting off again. I haven't noticed it this week, so maybe just needed some time to seat, and took longer than normal because of the glazed rotors.

I'm just curious if there's a service advisory from Ford regarding this, because based on this thread, it appears to be a fairly common problem. Perhaps there's a schedule for brake maintenance regardless of whether or not the pads need replacing, at least a minor touch-up on the rotors to keep them from glazing.

 

Old paint, I think as far as the fronts go, I think the way the calipers mount,There is to much metal on metal. Thats where I see them not releasing fully. I don't think it's the pads themselves sticking to the rotors. Like I said. Ever since I started greasing that part of the caliper,I have not had this wet weather problem. As far as the backs. Too many different driving conditions and load factors,To determine if it is an actual design flaw or not. jmo.

 

in addition to my 87 f150 I also have a 92 ranger it does the same thing after it rains the back wheels lock up for the first few miles in the morning I am pretty used to it now I know its gonna happen as for my 87 just got it and still havnt got the engine back in the truck yet but im sure it wil do the same that problem isnt isolated to the larger trucks just thought I would throw my two cents in "I love this web site"

 

cbslayer, Sounds like you might have a rear cyl. leaking a little bit. Pull your drums and take a look. It does't take much fluid to make them lock up.

 

Leave her sit outside long enough, and yes, the pads WILL stick to the rotors, especially the metallic pads. Mine do within 2 months. When I left it sitting for 6 months, I had to remove the front wheels and rap the calipers with a rubber mallet to get the pads to let go of the rotor. Disc brakes are designed to maintain zero clearance. They never retract fully from the rotor. That's one of the reasons that they are less subject to contamination than drums, because the pad will simply scrape off any mud that happens to stick to the rotors. Obviously, if you do a lot of mudding, this is going to play havoc with the pads and rotors eventually as sand will start getting under the pads. I greased mine thoroughly when I put the new pads on, making sure none could get on the rotor when it got hot, but it still wants to grab when wet and cold. Warm 'em up one time, and problem solved.

 

I will pull the drums today and have a look thanks for the input