93 Regal 3.8 - Engine surges when brakes applied

[RVANC]

I've read a vacuum leak will cause this problem and my wife heard a hissing noise when I applied the breaks on the way home for lunch. So I'm assuming a vacuum leak someplace in the brake system, but I've not found one yet using the carb cleaner approach. The brakes worked on the way home but on the way back to work they hardly work at all - very stiff. Could the vacuum booster be the problem?

Any help will be most appreciated. Thanks.

RVC

[maxwedge]

Sounds like a bad booster,disconnect the vacuum hose to the booster, plug it see if it improves, do not drive it of course!

[RVANC]

Yeah, I kind of figured that's what it would be. Thanks for your reply.

RVC

[RVANC]

OK, the booster is on its way off. Unbelievable how much stuff is under the dash! I noticed what appeared to be brake fluid on the booster on the inside of the firewall so I assume the Master Cylinder is bad, too. Could a bad master cylinder also ruin the booster and cause the leakage?

The following will probably reveal my ignorance about all this. My car has the anti-lock brake system and I'm pretty sure I don't want to mess with all that as I'm not very knowledgeable about it. If I am going to have to replace the master cylinder, too, can I convert somehow to a standard, non-anti-lock master cylinder?

[Blue Bowtie]

Your Regal should have the DELCO ABS-VI, non-integral ABS system. This means the master cylinder should be replaced normally, and without complications. If the master cylinder is properly bench bled and the ABS is functioning, bleeding the air from the wheel cylinders/calipers should be conventional with no need to exercise the ABS unit. The ABS VI is very friendly that way, and can be cycled if necessary just by turning the ignition key to the RUN position for five seconds to prompt an ABS test run cycle.

[RVANC]

Thanks very much for this. It's what I needed to hear. Now if I can just get the blamed thing out I'll be on my way.

RVC