dude my brakes are stupid.

It typically happens when it's cold (50's or so, this is SoCal....) before i've built any pressure (basically the first stop sign i get to)

My brake will feel very odd, but i can't describe it. It'll slip then lock up, in a very herky-jerky fashion. After that, all is good. Normally under medium-meduium/hard braking, but not nearly hard enough to make them lock up.

I've asked all the backshop techs at my work, and they don't know what it could be. Weird thing is it only happens in a particular condition. Turning my drums would fix it if it were an every-time thing, but this is only with no pressure in cold weather.

Does it have something to do with the brake fluid viscosity or my master cylinder regulator?

I mean, anything could cause it. My balding tires not having any heat to make them sticky. My brake fluid, which is pitch black. The cold whether affecting my patello femoral syndrome (dry kneecap).

What is the real reason?
it's a 2000, rear drums, no ABS

 

Would you describe them as grabby? On light braking occasionally one will grab, maybe even bark the tire? A trace of oil or grease can do that. Check for dampness where the brake plate bolts to the axle. Could be a leaking rear axle seal.

 

I believe mine have done that also, but only when I spin out on a wet road prior to appying the break...

Ok, here's another example. When you go to the track, you do a peel out to get your tires hot/sticky...then you line up and go. Well, when I did my peel out, I would have to brake to stop afterwards obviously, and they would have reverse pressure in them making it to where I couldn't push them all the way down for a few feet. Is this what you are talking about?

 

My 99 F-150 dose the exact same thing on the first or second stop when it is cold or wet. We took it to some different mechanics but no one seemed to know what the problem was. Cantrma is right about oil residue causing a grabbing condition but when I checked my drums they where clean. Finally I gave in and replaced the factory shoes and pads (about 140k mi on them), thought they looked fine, and it got a lot better but still locks now and then. The one thing that helped me is pumping the brake petal a few times right after starting the truck.

 

Mine does it on occasion as well.
Why ???

 

It’s just a guess, but how about rust developing on the drum/metallic shoes while sitting. The oxidation would increase the friction coefficient until it’s scrapped off by using the brakes.

 

At 13,000 miles??? That's when I felt mine do it.

 

Yea, I know it sounds strange, but brake drums and metallic shoes sometimes develop oxidation very quickly. Older drums seem more susceptible. Maybe it has something to do with heating/cooling cycles altering the metal. Check it out your selves. Next time you change your brakes, take a drum off, wipe it off with a clean rag and let it sit there over night. Wipe it down again the next morning and you will be surprised. If you get any dew during the night you will not even need to wipe it, as it will be visibly rust colored. Does it make the brakes act differently until the gunk gets scrapped off? I have no idea, but it might.

 

okay people, i have the solution....er, not really.

Last night i did a google search on i think "f150 drum sensitive"

It's basically an inherent problem of drum brakes. Moisture, which is prevalent in cold weather, actually makes drum brakes grab kung-fu grip stylee rather than slip, which is what we would assume.

Rust and corrosion can add to the problem.

New shoes will help, but not exactly solve the problem.

I'm going to take my drum brakes out and make my own stopping system. It'll be made of 100-lb actuators, a warn winch, and an anchor. Remove the tailgate and get creative.....

 

Mine does it as well. Can our drum brakes be converted to disc? Maybe a stupid question. Wouldn't be the first.

If it is possible, how extensive of a project would it be?

Rich

 

I'm sure that pretty much any brakes could be converted to disc with enough money.

 

Since rear disks were an options and/or standard equipment on many models, you just need to buy the parts and bolt it on or pick up a used rear-disk differential from the wrecking yard.

 

Any real benefit to doing so? Also, the models that came with 4 wheel disc brakes, were they anti-lock on the front and rear as opposed to the rear anti-lock that I have now. You know, the ones that do lock up now and then.

 

Benefits would be better looks, cheaper/easier maintenance sometime in the future, and more predictable and improved braking performance. It’s probably not worth the effort unless you drive very aggressively. I’m not sure about the antilock brake for the various years, but you would need to replace the proportioning control anyway so you could replace with a year that had the ABS features you wanted