Brakes are STUCK!!!

[JoshV]

I was driving my ZR1 today and on my way back from the store it felt really funny shifting. I went to leave a light and it wouldn't go. It would move but I had to give it a little extra gas to get off the road. I pulled into a parking lot and had a flatbed truck take me the rest of the way home. It seemed like the brakes were stuck. Has anyone had this happen to them? I'm thinking it is the brakes but I thought I would check with some other ZR1 owners. Thanks

[Tom]

Jack the car up so all four wheels are off the ground, put the car in neutral and you can easily tell if any of the brakes are sticking or dragging. You could possibly have an emergency brake cable sticking causing a brake drag.

[JoshV]

I thought it was the emergency brake too. I checked the car last night and the brakes aren't stuck anymore. The problem didn't happen when I tried to leave rather after I was a few miles from home. I'm thinking the brake fluid has been contaminated and when it gets hot it swells and applies the brakes. I don't think there could be an electrical issue that would cause this.

[Tom]

I don't believe your scenario is very likely because of the way the ports are set up in the master cylinder. There is a port in the master cylinder that directly connects the reservoirs to the brake system so that any increase in fluid volume would just push fluid into the reservoir. Here is a website that has a cutaway of a master cylinder that shows how the ports are configured: http://auto.howstuffworks.com/master-brake1.htm You can also click on the red arrows and see an animation of how a dual system master cylinder operates.

Caliper pistons can stick in their bores. Some cars in the past used plastic/phenolic pistons that were very prone to sticking and causing substantial brake drag. I've rebuilt several calipers on middle to late 70's Chrysler products I've owned that used the plastic pistons. During the rebuild you replaced the plastic pistons with metal pistons. I've never had a problem with my ZR-1 calipers and I've owned it since June 1990 but I also flush the brake system with clean fluid every year.

[Tom]

I made one typo in my reply I've actually owned it since June 1991.

[RedRiderZR1]

I had a caliper stick on my car when the caliper got hot. Wait until it happens again and lift the car up to see what wheel it is if you do have a stuck caliper. Next morning it would be fine. It came and went from time to time. I ended up doing a rebuild to the caliper.

Greg