All the pads and rotors are brand new, and I've replaced the caliper on the passenger front wheel twice now.

After about 2000 miles the right front (passenger) wheel starts to pull to that side, and with the brake off it acts like a scalloped tire. Probably a warped rotor from hanging up, question is WHY does it keep hanging. I drove about 15 miles yesterday and when I got back I couldn't touch the rim.

What gives? And does anyone have any info on the brake system? Seems the front lines split at the master and one goes to the rear. The rear line at the master goes straight back to the rear.

I'm tempted to buy some adapters and plumb in an S10 brake balancer just to see what happens.....

But first I figured I'd see if this was a common problem on these trucks. Anyone else have this kind of recurring brake issue????

Brake fluids are hygroscopic (water loving), which means they absorb moisture from the atmosphere under normal humidity levels. I do not know what kind of maintenance you did with your brake system but if your brake fluid has not been replaced in a while now is the time to do it.
The same happened to me. Whenever you change your brake fluid make sure you do a couple of cycles to make sure you have fresh fluid in your system.

Good luck.
<img src="/forums/images/graemlins/cheers.gif" alt="" />
Javy

Everything is new on the front, and all the fluid is new as well. I have an oil burner in the garage I add all my old fluid to so everything is treated with fresh fluids twice a year.

Thanks for the idea though, it has been a few months since I flushed the system and bled the brakes. Guess I'll start with that.

Anyone else have any ideas on why the right front keeps hanging? Is it the proportioning block (I wonder how much they run...)?

Always replace hydraulics in pairs. If you replaced the passenger's side, replace the driver's side too.

Are the hoses new? Not the lines. The rubber hoses. They can look good but be bad inside.

I got into it today, bled everything after a flush, checked the lines, and took the caliper off.

Same problem, I thought about that rubber line trick cause I had a jeep that did that, line kept fluid pressure in the caliper causing drag. Still have the same problem. Right front caliper is toast, it wont release. I tried cracking the bleeder, and then completely removing the the line as well. Put a big C clamp on it and its really stiff.

I know your supposed to replace stuff in pairs, but when I bought the truck the driver caliper was in really good shape. It was pulling to the right so I replaced the passenger caliper. I didn't have any problems for about 6 months, then the driver caliper went. Since I only put about a 1000 miles on the truck in that 6 month period the passenger caliper was pretty much new. I replaced the driver side only and within a week the passenger went so I again replaced that caliper. Now I have two brand new calipers on it.

One year later (about 3000 miles) the passenger caliper is shot again. I don't get it, I don't park over dirt, the truck has barely any surface rust on the frame, lines are all good, and I drove it maybe 4 times this winter in the slush. I'm pulling my hair out....

NEW QUESTION: Does anyone have a working proportioning valve they can sell? Also, how do you adjust them?

I'm really thinking about adding an S10 proportioning valve to this system and replumbing the brakes with all new lines and rubbers. I love my truck, its in great shape, and I want to make it diesel at some point.

I've replaced the seat with a 93 Toyota 60/40 bench bucket, Pacesetter header, Weber 32/36, Split rear window, Alpine radio, 4 pioneer speakers, American Racing Rims, fresh tires/alignment, fog lights, new grill, air horn, HID headlights on relays, new battery cables, triple gauges in the compartment under the radio, new clutch, new rear main and oil pan gasket, have a sun roof that needs to be installed, new mirrors, LED back up lights, fresh paint on the bumpers..... list goes on and on.

This brake issue is the only thing that's killing me. Really making me consider selling it, but I don't want to pass the problem on to some one else. Doesn't seem right to me.

Only thing left for me to try is the proportioning valve, but if I can't find an OEM style unit, I may have to resort to some redneck engineering....

Thoughts?

I would think if the rim was so hot you couldnt touch it, it probly screwed up the caliper. I wouldnt say its the proportioning valve since the driverside is fine. Even though you have already done it I would replace the caliper and the rubber brake hose as Tag suggested. If the the caliper was that hot imagine how hot that rubber hose got. They collapse on the inside. Can't tell just by looking at it. You said it had happened before so I bet that hose got hot then too and made it weak. All because your first caliper was bad in my opinion. Good luck. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Good point, wasn't thinking about heat damage to the hose the first time. I bet it wasn't in that great a shape when I bought it. It was pulling to that side when I drove it home, that's why I replaced that caliper and the rotors and pads on both sides.

I'm just glad the pads and rotor are still good, the caliper isn't hard, the rotors are a PAIN in the ARSE!!!!


Thanks for the info guys, I'll replace the caliper again, and the rubber lines on both front sides. Turns out I need rear shoes as well so looks like I'll be broke for a few weeks LOL.

Still curious about the adjustment for the proportioning valve though, I see a set bolt there on the lever attatched to the spring, and the bolt is bent up pretty good. I took it off and now I don't see any info in my book about the valve. It doesn't list it or refer to it at all. The bleeder still works so I got lucky there at least. Funky brake system, weird way to plumb it, but hey besides the caliper issues the truck stops on a dime...

When you replace the caliper, replace the upper caliper pin and lower caliper bolt, too. These are critical in that the motion of the caliper on brake release must be extremely free of friction to let the weak "stubbing the toe" of the pad on the disc move the pads just out of drag range of the disc. Since there is no "return" spring to do this, the stubbing is the only force that moves the pad away. Any binding on the upper slide/guide pin and the lower guide bolt causes pad drag. It doesn't take very much drag at all to toast the caliper and cook the pads. I've had dragging pads get so hot they disintegrated in a stop, not a happy feeling.

Mitsu's seem unusually prone to this. On even just a pad change I pull the caliper off the upper pin and check and grease the surfaces of the pin and bolt with hitemp silicone brake lube. I do the same with the places where the pad edges slide on the spindle iron - file/sand/scrape smooth and light smear of grease. I have fairly successfull removed rusty spots from the pin and bolt with crocus cloth, but you have to be dead sure you get all the abrasive off, which is difficult with silicone grease mixed in. Make sure the rubber pin/bolt accordion boots are watertight. There's a metal cap on the back side of the caliper that closes that end of the caliper upper pin bore, with a pencil lead-sized hole in the end to keep the upper pin from having an air cushion effect in the closed bore. I make sure there's a blob of grease covering that, as it is the primary source of water ingestion in the pin bore and that's what causes the rusting problem. Every hanging mitsu caliper I've seen is caused by this or a close variant, a rusted lower bolt from a torn boot.

Thanks Eddie, the upper bolt on the toasted caliper had a bit of drag to it. I bet thats what made it drag and get hot enough to ruin the caliper.

Guess I'll have to pull them and re-grease them every few months. I better look for some of that high temp grease too, I've been using axle grease.