1991 isuzu amigo, 175k miles (and still going strong!) 2.3L engine: I recently replaced all my brakes and rotors, because the rear brake pads (disks on all four wheels) were almost non existent. After I bleed the brake lines, everything worked great, no squeeking or grinding like I had heard earlier. Now, 2-3 weeks later, the rear brake performance is slowly deteriorating. It started as a high squul at 35 MPH. A hard brake stopped that. Then, it sounds like it is grinding again, and the rear wheels are very much hotter than the front wheels. Im assuming the calipers are engaging the brakes on the discs constantly, but I dont know why. I think it may be the master cylinder since it was a gradual deterioration of performance. Any ideas? Oh yea, brake fluid level is fine.
On the 89-93 isuzu amigo equipped with disc, the mechanism that engages (lever) on the caliper that connects to the hand brake, over a period of time will fail. Causing the caliper to not fully release which inturn leaves the pads draggin the rotor as the rotor gets hotter everything expands causing mot=re friction til they will almost drag you to a stop. I'm currently trying figure a way around the design but its not looking good. The other thing to check are the hand brake cables. There are two semi sealed cables that go where the main splits (somewhat easy to remove and check) but this cable over time will get dirt and crime inside cauing them not work smoothly or fully release. Last if its going to get really cold outside (below) freezing your rear brakes may lock up. Over all I love my Amigo but the brakes are worst a nightmare.