2003 Mazda B2300 break problems (front rotors will not spin)

did you check to make sure that the slider pins in the caliper cage are easily movalble in the cage.....the two bolts holding the caliper to the cage go into slider pins that 'float' in the cage. Very offen the bottem pins seizes solid in the cage forcing the caliper to hold the outer pad against the rotor.

Cosmo...Mazda Tech

[quote:1a203d4776="Cosmo"]did you check to make sure that the slider pins in the caliper cage are easily movalble in the cage.....the two bolts holding the caliper to the cage go into slider pins that 'float' in the cage. Very offen the bottem pins seizes solid in the cage forcing the caliper to hold the outer pad against the rotor.

Cosmo...Mazda Tech[/quote:1a203d4776]

After pulling the bolts out to remove the caliper, I pulled out the slider pins and lubricated them. When ever I put the pins back in the cage, the "rubber boot part is compressible and the pins can be pulled out fairly easily. They do stick a little at the mating surface between the rubber boot of the slider pin and the cage.

When I first assemble and before I push the break pedal, the rotors will spin. However once you push the break pedal and the caliper squeezes, the rotor will not spin freely anymore until I put a C-clamp on it and compress the pistons back into the caliper.

Should the pistons on the caliper automatically retract after the break pedal is pressed or should they still stay out with light pressure holding the inside pad against the rotor?

I have tried unhooking the hydraulic fluid line to the caliper once they are locked up to see if it was something upstream of the calipers causing the problem. However, they stay locked up even with the hydraulic line unhooked and the pressure being bled off.

Thanks for the reply and any further help. I appreciate it.

hmmmm......sounds like some sort of caliper problem then, but you say you replaced the calipers though. I know there is some residule pressure left in the calipers from the square seals around the pistons that will cause drag on the rotors. Is it hard to spin the wheels even with the tires on it.

Sometimes the calipers will 'work' there way in after a few km's

Cosmo....Mazda Tech

Yes the wheels are hard to spin even with the tires on it. I drove it around for a little bit last night to see if anything would loosen up, but no luck. You could feel the front breaks rubbing and putting strain on the truck. Whenever I would let off the gas it would feel like you were pressing on the breaks slightly, as the truck would slow down quicker than it should when it is coasting. The front rims were hot after I drove it also, so there was definitely a lot of friction going on.

This all started because my break pads needed replaced. Once i jacked the truck up, I noticed how hard it was to spin the front wheels(it literally takes all you got to spin it by hand with the wheel on). So, I took it apart and replaced the pads and it was still like that. Then I decided to replace the calipers, because I thought that might be the problem...and it is still locking up.

Other people that I have talked to seem to still think it is the calipers, but I just dont know. It seems hard to believe that the original 2 calipers would be bad and then I change them and these 2 calipers are bad also. If I would have changed them and it would have only been one side that was still bad...then maybe the "new" calipers had a probem..but what are the chances that I got 2 bad "new" calipers. I just think it is a slim chance.

I do not know what else to try...this has really got me puzzled.

The issue here is that you noticed the tightness before you did any repairs. Did you remove the hydraulic line at the caliper or at the brake tubing fitting? My guess is you have a restriction preventing the brake fluid to return to the master cylinder. Maybe a defective proportional valve if equipped or brake hoses. When wheels won't turn try disconnecting the brake line starting at the master cylinder and work your way down to the calipers. When the wheels free up you will have locate the point of the problem.