Master cylinder bad?

[JOEDEZZY]

When I'm in drive or reverse letting the truck move while idling, I apply my brakes, sometimes they grab sometimes they go straight to the floor. When I accelerate the brakes grab every time I hit them. I've checked my brake shoes and pads, they're in good shape, there is no signs of leaks any where and the master cylinder is full. I did have a vacum leak on my brake booster but I fixed that, I have no idea what could be causing this, any thoughts?

 

[JOEDEZZY]

also when I am in drive and apply the brakes, after sitting there for a minute or 2 the brakes will slowly go to the floor.

 

[JOEDEZZY]

never mind, i fixed it

 

[AZ79K5Project]

What did you find? Just curious.

 

[JOEDEZZY]

The master cylinder was bad, the plunger in there wasnt holding presure all the time, it was just weird because there wasnt any fluid leaking.