The machine burst a left drive hose which was then replaced but that side then wouldn't pull but would seemingly freewheel. It has a end of stack gear charge pump which is supplying pressure as right side works fine as does pilot controls for everything else. I removed pump group and checked the drive pump and found it in perfect visible condition. The planetary set and splines are good also. Reverse pulls but is slow to engage and forward drive is nearly nonexistent even with machine blocked up off floor. It has British metric fittings which are next to impossible to find locally but I am probably going to drill and tap them for something I can tie into. As it was run until out of oil, I was expecting to find an obvious hard part failure but not the case. Any similar failures with resulting problem like this?
Takeuchi uses JIS standard fittings, same as Hitachi and rest of Japanese equipment beside Komatsu, Kobelco and JSW. Sauer Danfoss uses ORB test ports but their diagnostic ports have odd ORB sizes 7/16 UNF, and 9/16. TL 130 have SD Series 42 tandem pump in 28 size. Manuals free on line. First thing I would check charge pressure right at system port (plagged diagnostic port right below system port) but at complete neutral using digital gauge, then servo pressures on both sides of servo caps.
Don’t pay attention to pumps name plate - those are Takeuchis codes not Sauer Danfoss.
Hate to disappoint you but if you didn’t pressure washed the tracks before changing hoses there’s chance you put dirt in to the new hose and scratched valve plate in the pump or motor.
I can only assume that the owner cleaned it before changing the hose. The area is clean but who am I to say how clean they were on install... I know I'm flying blind without pressure readings, mainly wondering what could cause it not to work after [simply!] replacing a drive hose. I performed a compressed air leakage test on motor with no audible leakthrough. Regarding pressures, will it not generate more than the minimum necessary to cause motor rotation which could be very little with no load? I'm thinking that the only way to effectively test pump output then would be to carefully deadhead or use a flowmeter. The real head scratcher for me is it will now readily move itself in left reverse after pump R&R but not forward leading me to think the servo control isn't reacting to pilot pressure as it should. If there was damage, shouldn't it show the same condition in both rotational directions as its nothing more than swash plate angle changing? With planetary disassembled, quickly popping the control to left forward got no shaft rotation but a gentle pull in would get it to turn slowly.
I just finished working on exactly the same machine, customer bought it unseen, one side was trying to go but couldn’t, had replaced motor on the same bad side. I tested pump with analyzer - it was only building up 1100 psi pressure. Upon disassembly showed scratches on valve plate and piston barrel causing cross port leakage. I think that motor went bad and previous owner replaced motor but didn’t clean the hoses. Then residual debris damaged the pump. The minimum you have to check servo pressures then go from there.
If you dead head the loop you can see the low pressure but you will not know which is bad, pump or motor. Series 42 have option for bypass valve, but the one I worked on - didn’t have the bypass valve. You can check if yours was accidentally activated.
If it moves in one direction but not the other it could be joystick valve or port relieve valve/shuttle valve. But “flying blind only causes unnecessary time/labor and parts losses, buying gauges will be cheaper in the long run.
Many thanks TVA! This is outside my normal repair type and the symptoms were such that I was anticipating obvious damage to the pump. I'm going to do a quick pilot hose switcharound to see if problem moves and if not I'll find fittings I can tie my gauge into. I saw the bypass valve in parts breakdown and will have to see if this unit has it.
I removed a test port plug, drilled and welded a test port onto it and am getting 6-700 psi on both left and right to just turn tracks no load so both being the same I want believe the pump is good. I have tapped into general pilot pressure and at mid RPM it is building 250 psi which drops a little when right drive F/R is selected and left reverse drops to 150 and forward down to 100. Combine both forward and pressure drops to 150 and right side slows while left barely moves. How a mere blown drive hose could cause this problem if it was done right is really puzzling me as I replaced a New Holland pilot control drive hose recently and it went right back to work.
Sounds like you have leaking servo piston/seal. One thing with a customers: some of them lie, some of them kind a clueless. The machine I told you about - the brother of the owner actually went out from California to Texas right after purchase and before shipping it, he test drive it and didn’t noticed anything! Because good track was pulling machine forward and backwards, but when loader was delivered and they tried to work with it then they find out it had the problems.
You can actually take pressure readings right at servo piston caps, 7/16 UNF ORB, but one of them is on the bottom of the pump. Did you swapped pilot hoses to see if problem is moving with a hoses?
Another thing: make double sure you are reading pilot pressure not charge pressure.
Finally had the nerve to lock the left track with bar and CAREFULLY ease it into reverse and it will only build 700 PSI (above what it took to turn tracks but WELL below operating pressure). I called and talked to the Landmark shop foreman and he believes it likely cavitated after hose blew and was run out of oil. I had a ditch witch that was told pump was bad and found chrome was peeling off motor interface plate and leaking out so that may be what happened here too. I'll update as I learn more. Thanks!
Finally found problem. There was scarring on the brass receiver plate face as well as the piston carrier face from I must assume enough run time without oil. Everything else looks good so I'm calling in AM about a carrier and plate if available.
Try lapping them
They ran this one too far. Deep scoring on piston barrel and plate is definitely junk. On mine I might try that though. Called Landmark and all needed parts are available. 700 for piston and barrel kit, 170 for plate, and a few other parts. not as bad as the $6k for a new pump stack as they only sell them in pairs.