NO BRAKES!

[F.X.5]

I have a 2008 F350 CCLB 6.4 auto 4wd. About two days ago I was coming to a stop and I noticed the brake pedal seemed a little low. I didn't think a whole lot of it and kept driving. The more I drove the more I realized that something is wrong. Very randomly my brake pedal will drop lower than normal (like I have a brake fluid leak). What has me puzzled is one second the pedal will be low and the next brake pump it will be completely full. Pump it again and it will be amost touching the floor before the brakes start working. I have checked the brake and power steering fluid, steering works fine and does not seem effected by whatever is causing my brake issue.

I do have another truck to drive but this has kept me puzzled the past few days. I've asked everyone I know to ask and no one seems to be able to point at one single part as the problem. I really don't want to start throwing parts at it. Really hoping someone on here has had this happen or has an idea of what it may be. Let me know what ya think.

Thanks in advance for the help guys.

 

[Big Angry Hillbilly]

If there isn't any leaks in the system I would say the master cylinder is going for a dump.

 

[Big Angry Hillbilly]

Or your caliper slide pins are seized and you're having to pump the piston out to the brake pad.

 

[4.0l sahara]

Master but it's possible that a abs dump solenoid could be leaking but doubt it.

 

[F.X.5]

Alright, I guess I'll get a master tomorrow and try it. Any special procedures needed? Or just bench bleed it and bleed the wheels? Never messed with a hydro boost setup before.