JD 301A brake issue

[Danny Rockbottom]

I have a JD 301A - the brakes worked fine, then the next time I used it the left brake didn't work. I can pump it and the pressure builds, but if I step on it it goes straight to the floor. I tried to bleed the brakes but there doesn't seem to be any air. Does anyone have any ideas?

 

[Tx Jim]

More than likely a valve in brake pedal housing isn't seating.

 

[Zebrafive]

Disconnect the steel lines to the brakes. Cap or plug, depending on whether you removed the lines from the brake valve or axle.
Try the pedals. If OK, the problem is in the brake(s) behind the axle housing.
If the pedal(s) still go all the way down the problem is in the brake valve. If the pedal goes all the way down when pressing one pedal or both together(coupled) the reservoir check valve is bad Key 31 in the drawing. If only one pedal goes down, but not when both together(coupled), it the equalizing check valve in the bottom Key 25-27
There is a reservoir check valve and an equalizer check valve for both sides, four total. Might be simplest to replace all four.