Brake locking up: how to fix?

[Cigars n scotch]

I could have sworn there was another thread about this that I even replied in but darned if I could find it while on my phone.

Anyways, one of my brakes is locking up bad, hubs get SUPER hot. Took wheel off, caliper and pads and from what I can tell the piston (I am guessing that it what it's called) is out too far. I pulled off the other wheel to compare and it seems to be locked out further than the other which means the brake pads are in constant contact with the disk.

Trouble is, I don't know how to get this piston to push back in. Any insight from you "much smarter than me" guys?

Here is a pic of what I am referring to:

http://i156.photobucket.com/albums/t39/newmanium/2008%20Supra%2021V/DE0D444D-2541-4EA0-9592-8A9D556BEB88_zpswefdj5hn.jpg (http://s156.photobucket.com/user/newmanium/media/2008%20Supra%2021V/DE0D444D-2541-4EA0-9592-8A9D556BEB88_zpswefdj5hn.jpg.html)

Thanks.

[ninedriver]

All you need is a "C" clamp. Put one end of the "C" on the back of the caliper and the other end over the piston, however, You'll need to have something between the end of the "C" and piston (small piece of wood or use the brake pad if you're careful). Pop the cap off your master cylinder in the tongue and then start tightening the "C" clamp. You brakes are a closed system so as you tighten the "C" clamp, it will force the piston back in the caliper, which will force the brake fluid back in the line and to your master cylinder. Depending how much room was in your master cylinder, it may overfill.
Now, unfortunately, there may be a reason the piston is hanging up. Could be an overfill of brake fluid, but more than likely its rust/corrosion within the piston/caliper assembly. By looking at your rubber boot, I would suspect that. Solution would be to rebuild your caliper and be sure to re-hone the piston cylinder, or simply replace the caliper entirely. I'm not sure what calipers are used, but I'd guess they're not too expensive and it'd probably be easier just to replace it than to buy the tools necessary for a correct rebuild. Either way, once you disconnect the caliper from the brake line, you'll also have to bleed the system.
Maybe someone could chime in with the type of calipers / brake pads and where to get them.

[Cigars n scotch]

Did a little googling and found something on the bu crew site where a guy stroked the push rod in the actuator, and I tried this and the piston is definitely out further now. QUestion is how do I get it to go back? Bleed screw, open it up? Just FYI I don't have proper brakes at the moment, my last attempt at bleeding them failed miserable (wife tried helping which was a huge mistake). I am making an appointment at a trailer repair shop to get them bled properly but if I can't get the pads to stop sticking then I can't even get the boat/trailer to the shop.

If I open the bleed screw will that release the piston's pressure?

[ninedriver]

Here's a link using a "C" clamp to help you visualize. If the actuator rod was able to push the piston out further, then the c clamp will have no problem pushing it back in. You don't need to open any bleed screws now as it's a closed system and by squeezing the piston back in the caliper, you're just forcing the brake fluid out the back of the caliper, through the brake lines and back into the master cylinder....just like when the tongue is depressed, it presses the push rod which forces the brake fluid through the lines to the back of the piston which pushes it out. When the brakes (tongue compression) is released, the piston should relieve pressure on it's own. It won't retract fully into the caliper, it just relaxes pressure to keep your pads for forcefully contacting your rotor (disk).
Unfortunately, your piston isn't relaxing that pressure and your brake is dragging causing excessive heat and wear. That is what ultimately needs to be addressed by rebuild or replace.

https://www.youtube.com/watch?v=FoTh3N15GUw

[Cigars n scotch]

**Edit: Let me run out and get a C-Clamp and see if that works. Thank for that youtube link. I hope this works and then I can order replacements but not be caught on land this weekend.

I don't have a C clamp but I do have Irwin clamps and tried your resolution but it didn't budge. I am guessing rust in the assembly?

I looked at Pacific Trailers and they have the replacement calipers and pads but that leaves me dead in the water this weekend (or I guess dead on land is more accurate). And we all know what B.O.A.T stands for....well this sucks, wife and daughter will be unhappy about this..

[ninedriver]

As far as getting trailer to the shop, just compress the piston like mentioned above. Go ahead and compress it all the way like in the video. Put every thing back together and install the brake lock out tool on your trailer. You won't have trailer brakes while you tow, but at least you won't have to worry about that caliper locking up.

[ninedriver]

Man, we must be typing at the same time. Go the walmart, or home depot , or where ever and grab a "c" clamp. they're cheap and it'll do the job. Those irwin clamps don't have the torque required. Then see my post above about the brake lock out and enjoy boating this weekend! A lot of guys tow without trailer brakes. Most don't even realize their brakes aren't working. Just allow yourself a little more stopping distance.

[ninedriver]

LOL, we are typing at the same time. I just saw your Edit... Good deal, grab yourself a c clamp and you'll knock it out in a few minutes. If you don't have the little lockout tool, I've heard you can put a 1/2" nut or a nickle or washer or something in the groove to keep the tongue from compressing. Whatever you use, you'll want to make a few passes around the tongue with electrical tape or something to keep the lockout tool in place.

[Cigars n scotch]

Big thanks to you ninedriver, that indeed did the trick. Picked up a c-clamp at HD and it worked. I've been towing without brakes for a while now and have done just that, "leave myself a good amount of distance", but I do need to get them bled properly and have them working as I park on hills and my truck brakes even with the e-brake don't hold well and it worries me.

At least we are ok for this weekend, thank you so much for your insight! I Love this forum!!!!

[ninedriver]

Sweet! Congrats! And for the mean time, pick up a set of wheel chocks from the Rv section of Walmart and chock your trailer while parked on a hill.
Enjoy the weekend and be sure to bleed those brakes properly when you replace the caliper. And yes, this forum rocks.

[gregski]

And for the mean time, pick up a set of wheel chocks from the Rv section of Walmart and chock your trailer while parked on a hill.
Whoa! Ditto this. I would never park on a hill and expect the truck's e-brake to hold it. You can get a pair for less than $10. I always keep them in the truck. If something ever happened and you had to unhitch the trailer away from home, you may need them.

[cornrickey]

Remove the calipers, drain the fluid (needs to be changed anyway) jam golf tees into the lines to keep water out and use it for the weekend.

[MLA]

Do you have a pic of the outboard pad? Mainly interested in its thickness compared to the inboard pad. Also, how does the suspect sides pad thickness compare to the other side?

There will always be a slight amount of pad to rotor drag. Too much causes the heat and excessive wear.......but.....you have to make sure that the opposite side is not the real problem. Too little drag, as in a caliper thats not clamping, causes the other side to wear faster. This can make one point to the side thats hot and has the most wear.

The two most common causes of excessive drag are frozen caliper slide pins and collapsed or kinked brake line, not allowing the pressure off the piston once the pressure is off the actuator.

So before condemning that side, take a close look at the other side.

[Cigars n scotch]

Whoa! Ditto this. I would never park on a hill and expect the truck's e-brake to hold it. You can get a pair for less than $10. I always keep them in the truck. If something ever happened and you had to unhitch the trailer away from home, you may need them.

Ok let me explain a little bit here so ppl don't jump to conclusions. I don't park on hills with no brakes, my driveway is sloped and I chock it with a cinder block. The ramp I go to has a hill and I can't pull to the side to clean up on it so I park at the top or pull in a parking space. Don't worry I am not relying on my ebrake. I am smarter than that.

[Cigars n scotch]

Do you have a pic of the outboard pad? Mainly interested in its thickness compared to the inboard pad. Also, how does the suspect sides pad thickness compare to the other side?

There will always be a slight amount of pad to rotor drag. Too much causes the heat and excessive wear.......but.....you have to make sure that the opposite side is not the real problem. Too little drag, as in a caliper thats not clamping, causes the other side to wear faster. This can make one point to the side thats hot and has the most wear.

The two most common causes of excessive drag are frozen caliper slide pins and collapsed or kinked brake line, not allowing the pressure off the piston once the pressure is off the actuator.

So before condemning that side, take a close look at the other side.

Thanks Mike. The wear on both sides is pretty even and there's still good thickness to them. I didn't snap a pic but I can this wknd. You amaze me with the bank of knowledge you have!!!

[MLA]

If the wear is fairly even left and right and inboard to outboard, then i would look upstream to the main lines and coupler. Make sure the short hose between the trailer and folding tongue is not kinking when the tongue is in its normal position. Brake pressure would be enough to pass past the kink when the coupler compresses. When the load is reduced from the coupler, the kink would prevent the the pressure bleeding off the calipers, keeping them applied.

[Whitey]

Looking at the holes in the rubber boot I'm sure the caliper is rusted. The only thing you can do is replace the caliper. I had 2 bad calipers early in the year. I tried bleeding the brakes, but it never lasted and the started sticking again. They can be rebuilt, but likely the piston is rusted and pitted if it is sticking. I tore mine apart and bought some parts to rebuild, but both of my problem calipers had rusted and pitted pistons. I bought new 2 new calipers, and fixed the issue.