Brake booster and a close call

This morning the brake warning light came on when I fired her up. No apparent leaking from the booster vacuum line or master cylinder. Went for a short drive to help diagnose the problem and could hear a faint hissing sound coming from down near the where the linkage goes through the firewall if I pumped the brakes when idling at an light. Looked to be dry down there though.

On the way back, some idiot pulls out of a side-street without looking and I end up locking up the brakes hard. (With the screeching and smoke, I'm sure he needed a new pair of underwear). Get back home, pop the hood and this is what my master cylinder looks like. I figured the booster diaphragm may have been shot but now I'm not so sure about the master cylinder too (which was very hot). What do you guys think?

Master cylinders don't get hot from braking but do get warm from near by manifolds and high engine compartment temperatures. Judging by the looks of your booster and brake lines I would say you need a little more maintenance and investment in that area.

Thanks Yatzee. Yeah, will replace it all. Just wondering what had caused the MC to blow like that. If it was the unequalized pressure in the booster in combination with the hard braking, or what?

What condition is the seal for the MC cap?

Cranky said:

What condition is the seal for the MC cap?

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It looks a bit rough, to be honest.

Now to track down a decent replacement...

69BBody said:

It looks a bit rough, to be honest.

Now to track down a decent replacement...

Click to expand...

Most likely why it's all wet but why the light came on could be due to a number of things.

Yeah, fair enough. Thanks Cranky. Hope to get this sorted out soon.