IH 444 Hydraulic Pump

capaci

New User
Can anybody tell me the correct procedure to check the hydraulic pump output pressure on the Cessna Hydraulic Pump on the IH444?
 
Yes,it has both,the loader has its own pump on the front of the engine,the 3pt hitch has the pump mounted on the side of the engine.
 
Hi, to check the pressure of the 3pt pump, if the 444 has a remote hydraulic outlet at the rear of the tractor, then just plug a
pressure gauge capable of reading at least 2500 PSI into the remote outlet and activate the 3pt lever to lift and you should
hear the relief valve buzzing, now take the pressure reading and it should be between 1500 to 2000 PSI with engine running at
PTO speed.
If the tractor has no rear remote hydraulic outlet then you are going to have to find a fitting that fits in the big plug in the
front of the seat where the rear remote outlet would connect.
The problem with the hydraulic system for the 3pt on the 444 is the relief valve is in the hydraulic control block in the front
of the seat. So if you disconnect the small high pressure line from the pump on the front of the engine and put a pressure gauge
on it, there is no relief valve in the circuit and lines and pump could explode.
Note, to properly check a hydraulic system both pressure and flow must be checked. To check flow requires a flow rate tester.
hope this helps
JimB
 
Jim,thanks for responding,I could really use some help with this.The 3pt hitch lift arms are all of a sudden slow,and weak,will not lift more than 200 lbs.We cleaned both filters,changed oil etc...we began to investigate.The power steering works fine,puts a small load on engine at idle rpm when turning.We can't get the 3pt hitch to put a load on the engine at all.We had the control valve apart while its still on the tractor,we do get flow through the isolation valve,which we had out,and flow through the npt threaded port on the front of the control valve housing.Also when we turn over the engine ,without it starting,we do see the flow speed knob move in and out,so we are assuming it is sensing oil flow.If I add a pressure gauge into the npt threaded port on the control valve housing,can I also use this same port to measure flow with a flow gauge? Thanks for your help,we do appreciate it.
 
mvphoto24824.jpg
 
Hi, yes that is the correct port that you can check the pressure and flow. To divert the hydraulic flow out this port put the
3pt raise/lower lever in about the half way position, then close the isolator valve and move the 3pt lever up and the oil should
be diverted out this port. Push the 3pt lever down below the half way point position to allow the flow to stop.

Does your 444 have dual hydraulic pumps(one for 3pt and one for PS) on the front right? or a single pump with a splitter block?

If it has a splitter block then it could be the splitter valve stuck such that to much flow is going to PS.

See attached photo, item#13 is splitter block, I can't remember if item #1 or item #11 is the splitter valve and the other is
the relief valve.
JimB
a281966.jpg

a281966.jpg
 
Jim,thanks so much,I would have never been able to find this info.My tractor does have the hitch/ps splitter block,only 1 pump to power both.I will look into a pressure gauge,and also look into checking the splitter block.I do have the shop manual,I'm sure it can tell me about the splitter block. You've given me enough info to proceed forward,again,thank you,I do appreciate the help.
 
Glad to help. I never worked on one with the PS splitter block. They were only used on the USA skid units.
All the ones we saw here in Canada were the UK built units with dual pumps sharing the return line from the reservoir.

Let?s us know the solution.
JimB
 
Jim,we finally were able to work on the IH 444 today.We attached the hyd pressure gauge to the control valve port,followed your instructions and we ended up with approximately 100 lbs pressure.We then plugged that port,removed one of the power steering lines,attached the gauge to the power steering hose,we have approx. 1600 lbs pressure at idle rpm.So we removed the splitter block,cleaned it up,took it apart,and I believe the spool may have been stuck.We are going to completely disassemble the unit,make sure there are no burrs,make everything move freely,and reassemble. We do have the shop manual,so we should be good with reassembly.Attached is the pic of the pressure gauge at the control valve.Right now it seems it's the best of all possible scenarios having the splitter block plugged,I sure didn't want to get into the lift housing at all.If you have anything to add please do so,since the unit is not back together,there may be something I am overlooking. Thanks for your help !!
mvphoto25220.jpg
 
Jim,we reinstalled the diverter block,no luck,we still have 100 psi at the control valve,the arms still do lift,and drop as I tell them to,they don't do it with any type of force.We removed the snap ring,the spring,from the control valve housing,the spring flew out of the bore,it must have been compressed a lot,the piston inside needed to be tapped out,so its not free floating( # 17 -18 -19 in the diagram).I'm going to clean out the .625 diameter bore in the control valve housing,reinstall the spring,piston,etc,and give it a go.
mvphoto25566.jpg
 
FIXED!!! the 3pt lifts as it should. We took a .625 diameter reamer to the control valve piston bore,I believe its a relief valve,we could feel a "lump" in the bore,we removed the lump,made sure the piston moved freely,reassembled,it works perfectly.I suppose the piston was hanging up on a burr in the bore,stuck in the relief position,the fluid was passing by the 3pt hitch back into the fluid tank. The end result was success,thanks for the input Jim !!
 

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