1999 Chevy express BRAKE issue. 911 Help!

Currently sitting in a parking lot trying to be a roadside mechanic.

1999 chevy express 1500. 5.7 150,000 miles


Brakes all sudden like went very spongy to the floor. Brakes still work(somewhat) to come to a safe stop here in the parking lot, but you can tell that something is very wrong. The brake light in the dash is turning off and on intermittently when I push on the brakes while in drive. Brake fluid reservoir has fluid in both sides sitting about 1 inch from the top lip. Front brake pads were just inspected and changed over a month ago with no issues from then till now happening since. It just happened very suddenly. I don't notice and fluid leaking anywhere.

Any suggestions on fix? Im actually walking distance to an autoparts store and would love not to have to call a tow truck. Thanks.

Can't really diagnose that from here, usually a leak causes this or a bad master cylinder, do you have Hydro Boost if so check the p/s fluid also.

Sounds like a leaking wheel cylinder or as mentioned the master cylinder. Look for a leak coming out of one of the rear drums.