85 K5 Blazer

Having a brake problem. I recently did a complete brake job, replaced both rotors pads and wheel bearings. Worked great for a few days. Then it developed a problem where whike driving down the road not touching the brakes the trk will jerk to the right requiring the driver keep left pressure on the wheel to stay on the road. I replaced the proportioning valve bled all 4 wheels tested it and it seemed to work fine for about 15 miles then it happened again. This time it continued to do it. Before changing the proportioning valve when i stopped the problem would go away for a few min until it started again. My next step is replace the caliper, does anyone have any other ideas what this could be.

When this happens feel the right front rim if the caliper is hanging up it develops heat. If hot hot pull right front tire smell the rotor if hot get a rebuilt caliper. The piston isn't retracting and causes this problem.
Was the brake pads on this side worn a lot more than the left side.
You can also rebuild the caliper.

Also consider a brake hose collapsed internally, common on old vehicles.

Thanks to both of you for the reaponse. Soon as I have a day off I'm gonna be working on it again. Let you know how it turns out.

Replacing the caliper fixed the problem thank you for the help. Had it out all afternoon on Saturday and it works great. Its for my son, hes coming home on leave next week and I wanted to have it ready with new tires and brakes.