Brakes lock up

[tgurley24]

After a few minutes driving the brakes slowly lock up until pedal is almost to the floor. Engine also starts coughing, misfiring. It will run but brakes heat up quickly. Brake lights remain on after engine turned off. Any ideas?

[rzcrisis]

Sounds like your master cylinder has failed. I bought my 64 Tbird coupe with that problem. I replaced the master cylinder and tightened all vacuum line connections and resolved the problem.

[tgurley24]

That makes sense. Going to dive into today. Thanks

[rzcrisis]

You can get a new master cylinder from a lot of sources. Not sure where you are but I got one from Macs in Lockport NY (I am in Ontario Canada).

You can (with lots of patience and a small mirror to look at bolts and nuts to remove that you will not see with the hood and crossmembers in the way) be able to replace at the firewall. Many will say you need to disconnect linkage to brake pedal under the dash but I was able to replace without that mess. Just takes time but you can do it. I was (and still am somewhat) a bit of a newbie to these birds but I find taking your time and taking pictures with a smart phone or digital camera helps a lot......remembering what something looked like before it is torn apart.

Hope you are successful.

Randy

[Cdhowell]

Sounds like you have a bad booster as well. Master cylinder alone will not affect engine performance.

[rzcrisis]

Yes you are correct. I failed to mention I replaced both the master cylinder and brake booster at the same time. The booster is what can cause the vacuum problems for sure.