spongy brakes after overheating.

[bIIcool]

I have a 1990 Bronco II 5 speed manual with a 2.9liter engine. My temperature gauge stopped work the other day and while I was driving around town (with the A/C on) I started seeing white smoke out from under the hood. After parking it and checking on it later the engine is fine. No more smoke. I am assuming it was only steam. This time when I tried to drive it my brakes were gone. I removed the vacuum line from the brake booster and found that I had brakes but they were very spongy. I have not seen any brake fluid leaking out and the vacuum line to the brake booster had sufficient vacuum. The strange part is that after I saw the smoke and before I parked my brakes worked fine. Has anyone ever heard of this or have any suggestions?

[clem]

Maybe you broke a line and it spilled on the exhaust causing smoke?

[greenmachine89]

The rear seal to your master cylinder could have gone out and now the vacuum line is sucking brake fluid into the engine. Had this happen before, now your brakes could be spongy due to air now being in the system