We have an F600 dump truck with duals. It runs fine except for the brakes. The brake pedal will not move at all -- only three wheels get a dribble of brake fluid; one of the front wheels gets no fluid at all. My husband replaced the master cylinder last weekend with no change in the problem. He replaced two wheel cylinders a couple of years ago. The brakes worked after pumping them but bleeding didn't help. Someone told us our problem was an airlock in the brake fluid. If that sounds likely, how does one fix that? If that isn't likely, what comes next?

LilahJ

 

I think I would take it to a brake shop. Couldn't cost a lot to diagnose. They also have the equipment to completely replace all the brake fluid and purge all the air.

 

Sam

I gaurantee the hose's are tosted. We use "if
you can't cross the no's" Chevy Nova they go
all the way up to F-900

 

Yeah, come to think about it, the hoses must be plugged. I totally spaced that out my first reply. I've seen them close up completely and not let any brake fluid through.

 

Haven't been reading messages because we've been changing brake lines

One was totally full of bits of rubber and rust. Put in all new brake fluid, bled the whole thing only to discover that the gizmo that attaches to the vacuum thingy was leaking. Found a fitting that worked, braized it on, bled everything again, and presto/chango, the brakes work.

Thanks for all the responses.

The carpenter's wife