This weekly Q&A session answers your questions about cars and trucks. This week explores a 2000 Chevy Impala that won't start at times, how to do an oil change, and a 1979 Dodge half-ton truck with master cylinder issues.

Question: 1979 Dodge Half-ton

I'm grateful for any help you may be able to offer. I'm trying to bleed a master cylinder from a 1979 Dodge half-ton with manual brakes. It's an aluminum housing with a plastic reserve on the top.

I bench-bled it before installing it with the hose kit. The front brakes bled okay but the back brakes will not pump fluid. I used the hose kit and bled again until there were no air bubbles. Once the line was hooked up, again it wouldn't build up pressure. Took the line off completely and gave it a pump and no fluid at all. I seem to have an air lock in the cylinder that I can't get rid off. I'm stumped on this one, I've never come across this problem before.