[dmjlambert]

Here is an update. As it turns out the problem was not resolved. The driver side rear drum brake overheats intermittently. When I drive around town, when I get to where I'm going I reach down and feel the hubcap. It is same temperature as outside, or it might feel hot to the touch. It has not heated to the point of smoking or that I can feel the drag of the brake engaged, but it is possible I have not encountered that severity of problem yet, and perhaps it's coming.

I don't often set the parking brake, and I don't think it is likely a problem with the parking brake. About 5 years ago I replaced the parking brake cable that goes to this driver side rear brake, because the cable was rusted and binding. The new cable appears to move freely.

To summarize the above posts, I replaced the shoes and cylinder and cleaned up and inspected the brake. I replaced the hard lines from the front to rear, the rubber line, and the hard lines on the differential.

Is it possible my master cylinder is bad, and could that cause just the driver side rear brake to drag and overheat intermittently? I have read they have a 10 lb residual valve in them for each of the brake circuits (front and rear) and I was thinking perhaps that is what is malfunctioning. The residual valve overcomes the spring in the drum brakes to keep the brake shoes nearly engaged, according to what I've read. I suppose there could be a difference in springiness from right to left brakes, but don't know.

I removed the master cylinder and took it up to O'Reilly Auto Parts because it has a lifetime warranty and I thought I would ask them to swap it, but when they tried to do that for me they found the part is no longer available. It was a rebuilt master cylinder and it is 7 years old.

They have offered to refund and then sell me a new master cylinder and I would pay the $50 difference between rebuilt and new. If I do that, the new master cylinder will probably get a couple of months of use before I remove it for a front disc brake swap.

I have a new master cylinder for disc/drum setup, but my favorite mechanic to help me with that whole brake swap is having a personal issue to deal with so we can't start right now. I was contemplating putting the new disc/drum master cylinder on and check it out running it on my 4 drum brake truck. The short brake line that goes from the front reservoir to the distribution block would need to be re-bent to move it out by 3/4 inch if I did that. I suppose I will not have the correct residual valve for the front drum brakes so it may affect the feel of the brakes.

I would be interested to know what you folks think.