[Dog Welder]

I got a 91 Toyota Pickup that I haven't driven in like 4 months cuz I was trying to figure out an ignition problem. Today was my first drive in it to work and I noticed that I was pulling hard to the right and making high pitched noises much like when your brake rotors rub. I get home and I notice that my front rotors (rears are drum) are hot enough to make a lot of water instantly boil off. Does brake fluid slowly expand over time?

 

[Discostu]

Dot fluid is hygroscopic meaning it absorbs water, so i guess technically yes it would expand over time in the presence of air. I just don't think leaving the truck out for 4 months would cause this kind of a problem with the fluid, plus if it expanded much it should just overflow in the reservoir. So I'm almost positive thats not your problem.

My best guess is that over this time period you accumulated a bunch of rust all over your rotors, causing them to rub and thus heat up much more than you're used to. I think this should just go away after a while.

We'll see what the true car guys have to say.

 

[Wumpus]

One of the pistons could be sticking.

Check and make sure the seal isn't cracked/blown and you aren't leaking brake fluid on the rotor.

 

[Wumpus]

I get home and I notice that my front rotors (rears are drum) are hot enough to make a lot of water instantly boil off. Does brake fluid slowly expand over time?

All the energy from stopping the car is converted to heat so your rotors are going to be very, very hot. If they were glowing or smoking then I would worry. I overheated my brakes in San Fransisco one day and they were making an awful clunking noise. Felt like the front end was about to fall apart.





Kind of related -- maybe -- One morning on my way to a ride this car was smoking and you could smell brakes pads burnings. Pulled up alongside her and the rear wheels were smoking. She obviously was driving around with the parking brake on.

 

[Wumpus]

Did they look like this guy's?

 

[dhtahoe]

More than likely you have a stuck piston. This happens often when cars sit. Treat it like a huge Hayes. Take both calipers off(2x19mm bolts), remove the pads, and get a pry bar to push the pistons back into the bore. Make sure you put a rag around the res to catch any fluid that WILL spill over. Spread BOTH pistons until they stop, and while your there you might as well put new pads in. Then put the calipers back on and pump the pedal until your brakes feel solid. Then check your fluid level, and your done. You should NOT have to bleed the brakes if done right.

 

[Dog Welder]

Thanks for the advice...I'lla be trying that this weekend...Found my old Haynes manual.

 

[Spunger]

It's for sure a stuck piston. Can they just magicly get fixed? No. Here's my honest opinion for this.

Calipers aren't that expensive. Don't mess or screw with changing the seals and such, just simply replace them. Maybe $50-75 for 2 new calipers (do both sides). You can probably get new pads as well for the front ($25-35 depending how how much you want to spend), a good size container of brake fluid ($5 at the most) and get a abrasive pad for a drill. Clean in small circles the rotor. If the rotor(s) are old replace them as well. It's your life we're talking about here so don't skimp.

Don't sit and try to pull apart a caliper. You can bolt a new one in in half the time or less then trying to dick with messing with the bores etc... Pads are stupid simple. Then just hook a line up to the bleeder valve and a jar and such (or if you got a buddy, have him watch fluid come out) and bleed the front brakes. Try to pump enough of the old fluid out so it ends up being new fluid spitting out. New fluid, new shoes, rotors if necessary and brake calipers and you'll stop on a dime with that thing.

You can try to press them in and see if that helps and clean the rotors and such if they are littered with rust spots. It might be a good temp fix but all in all it isn't much harder to just replace the calipers, rotors (if they just pull off, if not and you have to repack wheel bearings and such then it's going to take a little longer), change the pads and bleed the system.

Seriously though, brakes are key. Don't do the job and then second guess what you did. It's your life if the car doesn't stop so get some ideas, make a plan, and do it right!

 

[pigboy]

i've had this kind of thing happen on my old cars. check out the suggestions above and also you might want to see if the rubber brake lines between the caliper and the metal lines on the car are swollen. they can swell shut internally so that the fluid is unable to flow back into the rest of the system after you apply pressure to the brake pedal. this can lead to overheating rotors, pulling to one side and ultimately welding a set of calipers to the rotor (i've had this happen on an old car, it is possible).

so if all else fails maybe you ought to replace those 14 year old rubber lines between the calipers and the metal lines under the car. do it before you flush and bleed the system or you'll have to do that whole chore over again.

good luck,

pigboy

 

[merrrrjig]

sounds like ur gunna need some new brake pads too!