I have an 08 F-350 DWD -6.4 with 20 K.
Sat all winter in heated building and since spring has developed a very noticable sqeal - sounds like hydraulic pump starved for fluid - quits when I step on brakes.
Checked fluids - OK. Any Ideas before I take it in.
Thanks
Tom

 

Check the drive belts. They may have dried up a little bit and slip under power. It is not that likely but possible.
Then check the calipers. Make sure they float as designed. You should be able to slide them easily in and out. If needed clean and slightly lube the sliders or pins.

 

Have you had a chance to check all brake pads for wear?

 

Thanks guys will check out your ideas and let you know!
Tom