2001 deere 50c zts. problem real head scratcherany input would be great

travism · Mar 6, 2015

Hydo problem

The machine has great hydro power dig boom arm swing but when you track its slow to no movement.

But when you hit the relief like extending the thumb circut to max and hold it there the propel motors (tracks) r move as they should. Power

Deere enginers are stumped aswell
Pump pressurs good flow good

Could the combiner valve?
Crossover?

Why would pressure back feed the valve.

Im stumped
My number is 2537224123 if you need to call

Thanks

707 · Mar 6, 2015

Swivel joint. Pull off the case drain and see what your getting. Im taking a stab in the dark....but anytime i run across travel issues i usually start at the swivel. How many hours on the machine ? Does it have a blade ? Does the blade work as it should ? When the problem occurs, does it effect both sides ? Does tempreture effect when the problem occurs....

travism · Mar 6, 2015

Yes blade no problems
Yes both sides are effected the same
Temp gun is not indicating a propel motor problem
Can hit main relief with blade a travels as it should
Main relief gets hot do to oil passing by

Hrs 1500

707 · Mar 6, 2015

Can you lift the machine with the blade alone ? Try using your temp gun on the swivel joint. To be clear the "main" relief is getting hot apposed to the "circut" relief ?

travism · Mar 7, 2015

Yes it will lift the machine I'll hit the swivel in the morn.
If the main is bypassing how is it bypassing full flow pressure to propel .curcit. closed Loop system back feeds its reliefs? How would a leaky swivel flow more fluid when hitting the relief

This proble!m is backwards to all hydo problems it should have less flow slower propel. Instead i m getting better flowcpressurex

707 · Mar 7, 2015

A main relief wont backfeed into the pressure side, it will dump to tank . Unless you have a crack it the valvebank. It isnt a closed loop system either. Possibility of the what ever your are dumping over relief is is greater than the swivel leakage back to tank and and they both possibly are dumping to a common return manifold to the tank and then return element therefore canceling swivel leakage and allowing the propel to work. I dont have schematics infront of me. Its more of a thinking out loud....shoot the swivel before we start really scratching our heads. Have to eliminate the basics.

travism · Mar 7, 2015

I think your right 707 tank return is a manifold with main relief return teed into the same line as the rotary manifold

I'm looking at tech book
If your right I owe you a beer

707 · Mar 7, 2015

Keep me posted:drinkup

travism · Mar 8, 2015

Not the rotary swivel all test out good bench test. per tech manuel. Back to pounding my head against the wall. No metal in the hydro filter cut that open just to see if the pump was coming apart.

Any info to this matter would be nice

AndrewC · Mar 8, 2015

Kind of sounds like the pump isnt getting load sense pressure to bring the pump into stroke. What happens when you lift one track in the air and propel?

travism · Mar 8, 2015

It spins just slow both do the same. Put a load on it and my kids turtle can walk faster.
What season or how does pump2 get its sense load (relief) I've looked through the book

Andrew your right to me feels like the pump is not stroking up

lantraxco · Mar 8, 2015

Sounds like some kind of check valve or resolver issue in the valve bank to me... This machine has a single load sense piston pump, the division of flow is accomplished in the valve stack. I'm guessing what's happening is by deadheading a function you are shifting oil flow within the valve. By the way, does not make sense to me the main relief is getting hot, unless it or something else is malfunctioning. Usually in a load sense system the pump will limit pressure and destroke before the relief opens. Time to get your hands on a manual and work out the oil flow, pressures and flow rates, test with appropriate gear. Some dealers are better than others on dealing with these issues, YMMV.

travism · Mar 8, 2015

I have a book I left all my gauges at my shop its my house machine. It getting the full gauge setup on the pumps and valve might be pump1 or 2 relief I'm just going to set it up to stock or see what's going on this week I'll update after I test

Thanks for the brain storming

AndrewC · Mar 8, 2015

You might need to check your manual is the correct one. There is only one function pump the other is a pilot pump. There is no p1/ p2 relief. What is the cycle time on the blade raise/ lower at full engine rpm? Trying to narrow down where your to look but I think there is a load sense check stuck in the control valve.

lantraxco · Mar 8, 2015

Yeah, they show one section with main relief, then an end section with I think two more reliefs and a flow divider? Looks like each valve spool section has a check valve and some flow resolver spools? I'd like to see a colored flow chart explaining how all that works together, I might learn something!

travism · Mar 8, 2015

The book says 4 pumps
Pump1 pump2 pilot pump and a 3rd I'll have to look that up

I'm looking at flow through valve know might be back feeding a chech in the propel spool just wiered that both propel spools check would be faulty

The valve is the last thing in line I've tested and check most everything else
I'm looking in section 33-3360-76 left propel check #53

AndrewC · Mar 8, 2015

Its a 50CZTS? Im looking at a computer version so your pages mean nothing but I am wrong about asking about the blade speeds as the blade section doesnt have a load sense check. I think your problem is the ls check in right propel spool. I think its stuck closed and blocking flow for the left side ls. Before you go into it though I'd like someone with a bit more knowledge of these systems than me comment. See picture item 5.

travism · Mar 27, 2015

Got figured out was a travel valve bypassing ,not stroking the pump all the way thanks for everyones input

2001 deere 50c zts. problem real head scratcherany input would be great

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