1993 XJ Brake problem

This morning I got into the truck to go to work and when i stepped on the brake pedal it went all the way to the floor. I pumped them a bit and they felt fine. I cautiously too the truck around the block slowly and did a few stops. The pedal felt mushy and the truck didn't stop well at all.

I parked the Jeep and took my other truck then got home from work and took a look around. NO leaks at any of the wheels, checked the fluid and it was low. As I looked around there was brake fluid leaking from where the master cylinder meets the brake booster. I'm guessing that I need a new master cylinder.

My question is I've never done a master cylinder before but it seems simple enough. I've replaced calipers and wheel cylinders before, done some engine work, but brake work makes me nervous. Is it as easy as it seems?

It sound like a m/c for sure. Bench bleed it before you install it. That'll make life much simpler. Hopefully your booster is OK. Your brake fluid has been going into the booster & sometimes that will cause the diaphram to fail.You might want to think about upgrading your m/c & booster to a dual diaphram type while you're at it.

An upgrade sounds like a good idea. The brakes have been marginal at best since i got it. I'm going to redo all 4 corners while I'm at it. I've got a sticky right rear drum and a partially frozen front caliper by the looks of it.