John deere 444g won't engage forward or reverse

[Joeyschribar]

Here's up to scoop on an issue with the machine having full hydro operations but will not engage forward or reverse. First thing was this machine was running just fine as purchased it drove off the trailer and parked in the yard for a week.
A cold snap revealed some poor wring and batteries after a no start issue. After it was boosted and idling for a few hours it was attempted to drive into the shop but would not engage drive, so I drug it into the shop. All main powers, grounds, batteries were changed with new. After that we noticed the dash was no good and wiring harness so all of that was replaced, along with the wiring harness for your solenoid controls, parking brake and switch, alt, and a few engine sensors. It was detected that he parking brake pressure switch is broke. So it was left unplugged for now. All fuses are good as well.

The fluids and filters were also changed. Still won't engage drive. The forward neutral reverse solenoid has voltage and ground to each specific wire in either direction. The light was not on and the dust cap was missing on the solenoid so it was removed and inspected. The solenoid shuttles in each direction with voltage applied and only the light was corroded and not working. So reinstalled it after a good cleaning and still no go. The parking brake appears to not release at this point and the park brake lockout relay appears to be faulty as well.

My question is if I manually release park brake and jump that relay will it cause any unwanted issues on the machine. As well, even with the machine parking brake on will it not torque down a bit or will it just feel as if in neutral. As well on the neutral dump solenoid I noticed a small crack in the plastic housing and was curious if that is related in any way to not engaging the hystat transmission. If anyone as any other info or input to help solve this issue would be greatly appreciated. New parts: parking brake pressure switch and a new FNR solenoid are on their way as well.

 

[JWJDM]

Check left brake pedal see if it partly engaged and check linkage to pedal goes to dump valve for hydrostatic system

 

[Joeyschribar]

Check left brake pedal see if it partly engaged and check linkage to pedal goes to dump valve for hydrostatic system

I will have a look at that as the brakes do feel weak on their return spring. Thanks.

 

[Joeyschribar]

Well when I replaced the FNR SOLENOID it can now move woohoo. But I do have a problem with being unable to release parking brake. The brake releases but will not hold in the release position. I have to press and hold the switch to be able to do it. Curious on the configuration that controls that particular aspect.

 

[13K]

I am working on a similar problem with our 444G, we have had it in our shop several times since the pump (our mechanic calls it the hi lo pump) will not hold a charge. When we go to run it in the morning it will not move, so we crack the hyd line at the pump, let it bleed, then it charges up and works fine. For several days in a row when parked in the shop it never failed, then when parked outside at 35 degrees it happened - I dont know if it is temperature related but it is noteworthy.
Any ideas would be most welcome and appreciated.