How’s it going guys, I have an old 444 loader, it has no steering, won’t go into gear, and the bucket barely lifts at all, last mechanic to touch it replaced the pump, he didn’t even change the filters when he did it. I changed steering filters on it along with the return filter in the hyd tank. The suction screen was a disgusting mess, I have a new one coming Thursday but it’s not making sense to me why the loader won’t go into drive or reverse because of that. If this were a cat or Komatsu it would have been fixed yesterday but I am new to the jd loaders. In my mind it seems like something electrical. Thanks
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Jd 444 Hydraulic issues
Diesel Dave
Senior Member
Welcome to HEF korbind96 
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What model of loader , just a straight 444 with no letter designation ?
.What model of loader , just a straight 444 with no letter designation ?
Correct, it’s pretty oldWelcome to HEF korbind96
What model of loader , just a straight 444 with no letter designation ?
Welcome to HEF korbind96
What model of loader , just a straight 444 with no letter designation ?
Attachments
Diesel Dave
Senior Member
Which hydraulic pump did the mechanic change, the one below the radiator or the one below the operators seat ?
It’s A. I don’t know them. I worked on J.Welcome to HEF korbind96
What model of loader , just a straight 444 with no letter designation ?
The one below the radiator
Diesel Dave
Senior Member
Brief component layout of the machine ,
- the closed center steering and service brake functions are supplied by the hydraulic pump mounted under the radiator. The pump is supplied oil from the transmission. The pump is driven by a coupler on the front crank pulley.
- the open center loader functions (boom and bucket) are supplied by the hydraulic pump under the operators seat. The pump is supplied oil from the hydraulic tank. The pump is mounted to a flange on the transmission charge pump.
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Off the engine flywheel housing is a short driveline that powers the torque converter/ transmission, make sure it is turning.
Check the oil level in the transmission with the engine running.
Is the oil clean and with no burnt smell ?
Check that the transmission clutch cut off control knob is ”in“ .
The knob is on the vertical panel just below the operators seat.
What’s the dash mounted transmission pressure guage reading with engine idling ?
- the closed center steering and service brake functions are supplied by the hydraulic pump mounted under the radiator. The pump is supplied oil from the transmission. The pump is driven by a coupler on the front crank pulley.
- the open center loader functions (boom and bucket) are supplied by the hydraulic pump under the operators seat. The pump is supplied oil from the hydraulic tank. The pump is mounted to a flange on the transmission charge pump.
.
Off the engine flywheel housing is a short driveline that powers the torque converter/ transmission, make sure it is turning.
Check the oil level in the transmission with the engine running.
Is the oil clean and with no burnt smell ?
Check that the transmission clutch cut off control knob is ”in“ .
The knob is on the vertical panel just below the operators seat.
What’s the dash mounted transmission pressure guage reading with engine idling ?
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That helps me a bunch but also none at all as I’m not next to the machine haha, I have a feeling the mechanic before me didn’t get flow off the pump and ruled it out, a little understandably. But from my understanding on this model the transmission and other hydraulics require separate pumps and separate oil, I can’t see why the transmission pump would send oil to the other pump, when there’s a suction screen in the hydraulic tank going to the acc pump. Especially when it says do not run the same oil in the transmission as to the acc pump in the owners manual, with that being said my brains hurting on why it says that, yet I have no steering, boom functions, reverse, drive, but the brakes work fine
Diesel Dave
Senior Member
Just so we are talking the same language.
The loader pump (mounted to the transmission below the cab floor) supplies oil from the hydraulic tank to the loader control valve for the boom and bucket cylinders is shown in screenshot below.
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The loader pump (mounted to the transmission below the cab floor) supplies oil from the hydraulic tank to the loader control valve for the boom and bucket cylinders is shown in screenshot below.
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Diesel Dave
Senior Member
Okay thanks for the diagrams, this is a little head smashing to me as to these issues happening at the same time
BobaUA
Banned
Are oil levels in both reservoirs OK?
IF yes, i would suggest checking splines on drivelines and couplers.
Or if there any ball/gate valves installed on suction lines - see maybe he forgot to open them up.
IF yes, i would suggest checking splines on drivelines and couplers.
Or if there any ball/gate valves installed on suction lines - see maybe he forgot to open them up.
Oil levels are good, coupled to pump under radiator is good, I will check for ball valves, supposedly they parked the loader one night, then came out to run it the next day and this problem happened, then he installed the pump and no change
Diesel Dave
Senior Member
@korbind96 ,
What’s the dash mounted transmission pressure guage reading with the engine idling ?
Is the short driveline between the engine and the torque convertor/ transmission turning ?
What’s the dash mounted transmission pressure guage reading with the engine idling ?
Is the short driveline between the engine and the torque convertor/ transmission turning ?