We have replaced brakes on this loader and now no matter what we do, there are no front brakes. Tried all the obvious. Has anyone else experienced this on this machine?
It would help you more if you could give some added info. What series 821/821B ?. And a s/n would help due to so many changes so we can talk the same machine.
It is just an 1990 821 model (no series), s/n JAK0023676
brakes You have to have good air pressure from the foot brake valve to the front brake actuator. The diaphragm actuator must not be leaking to be able to stroke the master cylinder plunger. The master cylinder must have brake fluid supplied by the reservoir holding tank and the seals and plunger must be able to build pressure when the actuator strokes. The lines from the master cylinder must not have crimps/blockages. The flex hose cannot have a internal restriction (inner liner separation) blocking flow. The calipers have to move free in the bore, clean of mud/dirt build up not allowing them to compress the disk brake pads. I would hook a air hose in the system to maintain air pressure while bleeding the system out with a helper in the cab to apply the brake pedal as needed to bleed the system. If while bleeding it can not produce fluid, I would check the lines from the brake fluid reservoir to the master cylinder for blockage and also check for air leakage and stroke from the brake actuator. If you have stroke and fluid but still no pressure after lines and all have been checked replace the master cylinder seals and plunger or complete master cylinder and re bleed the system. You may find that the air system is full of oil/water that needs to be cleaned out. You should also check the specs for your brake fluid, if your machine was set up for a hyd oil fluid and a DOT 3 was used, it could have damaged the seals in the master cylinder and swelled the caliper seals to the point the pistons can't budge. More later.