Brake pedal to floor, thumping, steering wobbles

[Wondercookie]

1991 Ford Explorer
4.0L
4-door
4WD
V6

Recently, my little brother was driving when his brake peddle suddenly went to the floor. There was a loud banging, he said, and to get the vehicle stopped he had to stand on the brake peddle with both feet.

I've replaced the brake booster and vacuum checking valve and hose. Upon test driving it afterwards, the brakes worked fine for one or two pumps, and then immediately went to the floor again.

The steering seems off suddenly, and can pull to either side. There is also a THUNK! from time to time.

When coming back from the test drive, I had to stand on the brake peddle with both feet to get the vehicle stopped.

Any ideas? Before this, the vehicle ran fine, he said. The Check Engine light came on just before his brakes went out. Is it something to do with the vacuum? Maybea leak? Thank you so much.

 

[snoranger]

Did you pull the wheels and check all the brakes? caliper mounts? etc?

Did you scan it and see what code came up?

 

[Anime]

Probably needs a new master cylinder.

Also check all the brake lines front to rear, the front and rear hoses, and the calipers and rear cylinders for leaks.

 

[Wondercookie]

Thanks, guys! I really appreciate this. I'm going to check those things out later today and tomorrow. You guys are great!

ALSO - just thought...there is no fluid leaking. I got a can of carb cleaner and some vacuum hosing to repair any possible leaks there. I plan on taking the tires off and checking the calipers later on today, then I'll get him a new master cylinder if that doesn't fix things. Once again - thanks!