i have a 642 and it will not move forward or backwards...but hydros for the boom works it goes up and down and bucket tilts just fine but nothing in the sticks..it doesnt move forward or backwards ...well i guess i shouldnt say doesnt move ..i jacked it up today and had all fours off the ground and they would move but very slugish even with no load..what do u think could be my problem....
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As the lift/tilt works that means the connection to the pump is still good. The hydraulic pump is the last in the line of 3 pumps.
It could be a piston pump issue or bad drive motors.
Is there a square block on the hydraulic pump with three hoses coming out of its left hand side?
ok a little more info ..it does have the square block with three lines i have not yet checked the filter in the middle line yet ...that was gonna be one of my next steps.. i bought this machine in non working order from a friend he used it everyday for years and then one day his brother was using it and said he ran it out of hydro fluid..yikes he then changed the fluid and filter and after that the machine would just go in circles ..one direction.. the weird thing i dont understand is when i got the machine after it sat for awhile i could start it up and it would go backwards and forwards but i had to really push the sticks hard. so this makes me think that the drive motors work.. it almost seems as if there is a collapsed line or kinked line ..or the pump is starving for fluid???????? i dont know
7LBSSMALLIE
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- Feb 2, 2012
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i may be wrong havenet seen one in awhile if the hyd filter is located under unit for access. they are known for suction leaks 1 make sur filtrer did not get double oringed. old school trick for suction leaks is shaving cream spread it on and look for dimples. second look in hyd tank is oil white and foamy.
the filter is located in the engine comp. on right mounted above everything.. the fluid is a litte airrated bubbly however you wanna call it lol ..and it is a bit milky. the fluid also seems very thin like if i stick a stick in the tank it runs right off the stick kinda runny..
mrdeere1959
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milky and thin sounds like water in the oil. would not hurt to change oil and filters.
As it was run out of oil, it could be more serious. Start with the filter and an oil change, if its the same, time to pull the pump and check it for damage. Aftermarket parts are still available for the pump.
how much is it to rebuild the pump you guys think.... is there somewhere to send them out to??
If you do the work your self, it will cost you about 6-700 in parts.
Two rotating groups, two wear plates and a seal kit.
I haven't bought them in a while, so it may be a little more.
Depending on how bad the damage is, you can some times flatten the wear plates with a sheet of glass and wet and dry sand paper.
ok so i took bronze filter off last night and got the metal coller off and it was filled with stuff almost to the end of the metal coller.. it was nasty stringy looking gunk.. cleaned it up with some kero. and put it back in drained all hydro fluid tomm. i am gonna fill it up and try it put i will keep everyone posted ...what kinda hydro fluid should i use ...????weight
Good find with the bronze filter.
You can use 10W-30, 10W-40 or regular pink hydraulic fluid. I run 10W-40 in my 642.
I added a couple of gauges to my 642 so I know what it is doing....I added an engine oil pressure gauge and a hydraulic charge pressure gauge. Charge pressure is easy to get out, you can install a tee in the line where the idiot light hooks up at the charge block on the top of the pump assembly. Depending upon what setup you have, I believe the stuffing pressure of the hydrostatic pumps should be between 100-115psi. This is the discharge pressure from the hydraulic pump (Vickers 10 series pump, the pump at the very front of the machine) as is stuffs or charges the hydrostatic pumps. The hydrostatic pumps (usually Vickers TA1919 series pumps are the two pumps that control the left and right side drive. As was stated earlier, the hydraulic vane pump is easily damaged if you let it run dry. A gear pump is much more robust, but all 642's shipped with vane pumps.
anyone out there have a used pump for sale ...
hey guys i got it goin good... changed hydro fluid and cleaned that bronze filter and away she went thanks for all you help ... also looking for a wiring diagram on this as well the previous owner diconnected all safety stuff and i would like to hook it back up.. thanks
Just what wiring has been removed? its a pretty simple machine.
What safety bits were removed too? the main one is the seat bar and pedal lock outs. The rest isn't for safety, its to check if there is a problem with the engine/pump.
Engine temperature, engine oil pressure, pump charge pressure/temperature plugged hydraulic filter. That's about it. There is a volt meter and a fuel indicator too.
