Rear passanger side brake locks up when stopped

There is a chance that your Brake Hardware failed and is jamming the Wheel

But more common is the "WHEEL CYLINDER" or Brake Caliper is froze and not releasing

This is Common with a Wheel Cylinder Failure.

Additionally, if you use your Hand Brake, it could Corrode the Cable and do this but I am putting my money on Wheel Cylinder

Hi Terry,
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Here you will find the details regarding your Car and how you can check and repair the breaks without taking it to a mechanic.
I hope this helps.....

Its probably the rubber hose that goes between the metal break line and the caliper. That hose is like a 2 way valve that lets fluid into the caliper when brakes are applied and lets fluid back out when brakes are released. These hoses deteriorate and stop letting fluid back out causing the brake to stay tight against rotor.

You probably have a brake slave cylinder that the pistons have popped out of. You will have to remove the tire and brake drum to take a look. If the components inside the brake drum are loose or out of place, lift the rear end of the car up on jack stands and use the brake panel assembly on the opposite side of the car as a reference on how to rebuild and replace the damaged components on the locked side of the Caravan. You will need a slave cylinder and new brake pads because the old shoes will be fluid fouled.

hi this sounds like your rear brakes are warn and the metal grinding noise you can hear might be the metal part of the pads rubbing on the disks, either that or your break shoes are doing the same if they are the drum type rear brakes, hope that helps

make sure the rear shoes are manually adjusted up properly ,then is still no good renew the master cylinder because the seal between the front and rear chambers could have gone ,but i do feel that you should manually adjust the rear brakes up properly,slacken handbrake cable before you do this though

The rear brakes should last from 30000 to 60000 miles or 50000 to 100000 kms. So something is wearing out your brakes too fast. Are you doing the work or some shop. I also assume you have discs and not drums since you mention pads and calipers. I am not certain but usually you need a tool to turn the pistion in when putting in new pads. I would make sure the pads are releasing properly by raising rear of car, stepping on brakes a few times (with engine off and try see if wheels are free by spinning by hand, also try to use handbrake a few times and release it and see if wheels spin freely. Maybe rears always applied. Notice burning smell, are discs glazed from heat? Are you using really cheap pads. Also check the proportioning valve which will decrease pressure to rear brakes during hard braking. Do you notice rear wheels squeling during hard braking. Do you have antilock brake system? Also are you using good quality pads and rotors.

You may have a collapsed rubber brake line at the rear axle holding pressure in the line . Have your brake lines ever been replaced? At this age it would be a good idea to do anyway to avoid any other issues .

remove back wheel and drum should come off sound like broken brake spings

Not wanting to be too general but at least trying to help I would suggest looking under the back end, and specifically at the rear backing plates and to the insides of the rear wheels, to see if you notice any fluids dripping. If these are drum brakes, then you could very well have either a wheel cylinder leaking brake fluid, causing the brake shoe linings to swell up, or it could be a leaking axle seal, allowing differential gear lube out, which will also cause the linings to swell, and minor braking will cause that particular side to lock up.
If this vehicle has rear disk brakes, or was just recently changed from rear drum brakes to rear disk brakes, it is possible that the proportioning valve in the brake line was not changed to match with the disk setup.
Drum brakes operate at approximately ten pounds per square inch pressure (10 PSI) whereas disk units operate at a lower pressure of about 2 PSI.
Just some things to look at. Some brake fluids have no smell, others are very distinctive in odor, and differential gear lube has a very distinct odor...not hard to miss once you've smelled it.