When digging or swinging under load,, the whole machine shimmies,,, like the pump is vibrating,, I have new filters coming in am and changing the fluid, as it is time anyhow.. Is there something else it could be??? Wiring,, or pumps going? Thanks all.
What happens when you just dig a good bucket full and dump it back out in front of you with out swinging. Later Bob
Same thing.. Anytime I put a load on hydraulics. The fluid is pretty dang thin though. No water in it,, just worn out. Fluid is full too. No leaks. Never had to add a drop to it yet..
Look for the case drain filter, change it and cut it open, think you will find brass. That shimmy sounds to me like you have one piston in your pumps not pumping. The case drain filter has lines running from the drive motors up through the swivel, joining the swing motor and the pumps and then through the filter and back to the tank. May be two filters, some pumps (Rexroth)have no casedrain line. Good luck with it, come on back with whaat you find. Later Bob
That makes sense,,,, I thought the fluid being really thin might be part of it,,,,,
When you say a"shimmy" is that a vibration???
Yup... Its is feels like if you are running out if fluid,, and it shakes. But it doesn't jerk or quit it is just slow. Might as well say f- it and just put new pump in
ya prob best option but maybe get someone jus to check it out with pressure clocks before ripping it out.....think the 150 has main hyd filter at top of tank but maybe some strainer in bottom tank as well...is it an older 150-1 or 150-5lc
It's a 150-3 year 97 I think.. No brass or metal in the main filter but will see what comes out when I drain the tank
Is that EX or FH hitachi...
Ex. It's been a great machine.
Afraid im lost so.... hitachi never released a 150-3 over here in ireland so im out!!!! Best of luck anyways!!!
I am not sure if it is a – three either way it's a 97 hitachi 150 Ex. Whatever the hell that makes it
If you don't have a lot of ground up brass, don't rush to change the pump. It might be a problem with the pump control. If you don't find much metal, leave the machine runnable and get mechanic that knows your machine. I don't, just refering to general exc systems. Later Bob
Does your pump look like the one on Mexle's 120, That pump looks like a Rexroth and has no casedrain line, The case is the suction of pump. Later Bob
Yup it sure does.
Run your machine at high idle and feel the pressure lines, see if one has a heavy pulse more than the other. That will indicate a problem.Then when you change the hyd oil, take the suction line off of the pump. You will be able to see inside and tell if there is much dammage. Later Bob
Nothing in Oil other than a a few specs in the sun... Normal. Fluid looked really clean. Filters dirty but no metal in them... I am leaning towards a bad coupler???? Will know more in am.
The couplers do wear out, that's a money saver. Look for all the cheap stuff first. If you change the coupler, check and record the position of the coupler on the pump shaft. Also good to check crankshaft end float with pump out and after it's back in. That makes sure the pump isn't forcing on the crank and loading a thrust bearing. Later Bob
While you have the oil out of your machine, see if it has a return checkvalve. Some machines use them to hold backpressure in the swing motor case so the makeup valves have a good supply of oil when the swing is coasting. I have seen one of them come apart on a small cat(320) and cause a more severe case of what you describe. If your machine has one it will be at the end of the swing casedrain line I would think. In addition anything blocking the return oil going to the cooler,filter and then tank. Later Bob
Hi all, sorry for the intrusion, may it be that the main pump is "cavitating" due to low hydraulic oil level?
No oil has never been low. The coupler is intact but some of the pieces are loose... The hydraulic shop is checking it all Out. Dealer wants 6000 for a new pump... So worse case it not too bad .
Don't jump at the new pump just yet. Look for a cooler bypass/ slow return check valve for the swing. Shooting in the dark again here but your machine likely has something like it. I saw a pump replaced with similar complaint to yours and nothing changed. Found check valve in the cooler bypass slow return check body backed out and restricting return oil flow. Later Bob
Does anyone on here know where something like that is on the hitachis? thanks for all the help!
We checked all the reliefs ,,, then last ditch took the pumP out. It had a ring come off a piston and trashed a head. All new pistons and both heads, o rings, and bearings going back in. Everything else looked pretty good. Thanks for all The help... Got a great shop working on it..
I hope that solves your problem, usually as you described, sounds like the problem is air (low oil level, loose intake hose, crack manifold, bad o-ring, etc.) lets your pump sucking air and makes the pistons cavitating and the whole machine shakes when pushing joystick more as your demand more flow, low idle is fine usually.
It's never been low on fluid . Never had any leaks, yet.... but they are putting new o rings back in and new gaskets. And new shafts in pump. Should be good as new. Thank god we found all the parts easy. I appreciate everyone's help!
Had pump Rebuilt. Works great now. All New internals in the pump. It had a ring come apart on one of the pistons. Thanks everyone!