5105 brake problem

[buck4779]

I have a JD 5105 4 WD. I just changed the hydraulic fluid and cleaned the pick up screen. This is the second time I have had to do this due to water getting in the system. The screen was completely gummed up with muck. I found crumbs on the screen of what looks like circuit board material I am guessing it might be brake material. I noticed that the linkage for the breaks was to tight causing the break to lightly engage at all times. I loosened the linkage and tested the brakes left side works as it should right side peddle oscillates up and down with the rotation of the wheel almost like a cam action. The right side works but you have to allow your foot to float up and down with the peddle in order to slow brake.
(1) How is water getting in the hydraulics.
(2) Thoughts on the brake

 

[fuel doctor]

I have a JD 5105 4 WD. I just changed the hydraulic fluid and cleaned the pick up screen. This is the second time I have had to do this due to water getting in the system. The screen was completely gummed up with muck. I found crumbs on the screen of what looks like circuit board material I am guessing it might be brake material. I noticed that the linkage for the breaks was to tight causing the break to lightly engage at all times. I loosened the linkage and tested the brakes left side works as it should right side peddle oscillates up and down with the rotation of the wheel almost like a cam action. The right side works but you have to allow your foot to float up and down with the peddle in order to slow brake.
(1) How is water getting in the hydraulics.
(2) Thoughts on the brake

The water more then likely is getting in around the rubber boots on the shifters . The right brake is that brake pad has not come all the way off so you have high and low spots on the disk making the brake pedal to go up and down

 

[Tx Jim]

On brake pedal moving up/down that sounds as if brake disk is warped. Water in hyd oil can be caused by boot(parts key 7) is probably cracked. Also be sure the hyd filler cap breather is plugged with dirt.

 

[buck4779]

Thanks Fuel Doctor and Tx Jim.
I did a walk by inspection of the shifter boot. At first glance it looks good i will put my glasses on and give it a good look next. What does the filler cap breather cap suppose to do? Equalize pressure in the reservoir as the fluid is mover in and out of the cylinders? Could it suck water in while operating in the rain? It was a little dirty and I noticed that it is designed to vent.
I am not sure about the water intrusion yet but it does sound like a brake job is in my future.

 

[Tx Jim]

Heating/cooling of hyd oil plus ambient temp changes can cause condensation. The breather in filler cap is suppose the let heated condensated moisture evaporate through the vent.