Hey All,

I have an awesome 85 300SD with around 215,000 miles on it. The brake fluid had been getting low and I narrowed it down to a leaking brake line with a hole by one of the mountings. Replaced the line (and I didnt leave it at the shop after they told me I needed a new master cylinder and that the hoses were fine, more reason to DIY) BUT now I am having tell-tale vaccum booster problems.

I replaced the hose and started it up and the pedal felt soft because there is air in the system. All is good, it doesn't feel mushy like before when there was a leak. However, when I went to shut it off with the brake depressed, the engine kept running for a while after i pulled the key out!

I know this is usually a problem with the vaccum booster. How can I go about diagnoising the problem? It certainly wasn't like this before I changed out the line. Could this be a problem because there is air in the brake lines?

Thanks