Zx160 Lc Weak Hydraulics With New Pump

Best Practices for Zx160 Lc Weak Hydraulics With New Pump

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Good dayOn many occasions we are finding that the issue is with the source that of the engine.Kind regardsUffex

Bump, still not fixed, anyone got any ideas? Please

Is there a dash number? ZX160LC-#? Serial number as well.

Its just a zx160-1. Its the last of the non common rail engines

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I don't have specs to offer but I would get a service manual and check engine power with a boost pressure check. If that checks out OK, then I would check the engine pulldown spec (both individual and combined pulldown) to see if the hydraulic pumps are adjusted correctly. Just to confirm these are mechanically regulated pumps and not electronic pumps, correct? Maybe post a picture of the pumps.

The engine is making good power and pulling the correct revs under load in all modes . I run in H/P and it boosts up as it should . The brand new pumps have been professionally fitted and setup by the Hitachi agency. The pumps do run a electrical torque control and regeneration system. They have looked at both of these, but they are missing something. The tell tail major sign something is wrong is the hydraulic oil temperature. It can crack 90 degrees on only mild work and not a really hot day. The oil cooler has been out checked and flushed, all good. So this to me points to oil bypass creating heat but where?

Are you using Hitachi oil? If not, what viscosity oil are you using? Has the oil cooler bypass valve been checked? Does your engine operate at normal temperature?

Yes new pump has had all new Hitachi oil in it. Yes the Hitachi service man who is regarded as on of the best checked the bypass valve. He said it was fine. If I remember correctly he did say it was a bit sticky to remove, but he wasn't concerned. The engine runs a normal steady temperature about halfway, other than when the hydraulic temp gets in the 90's, it starts to get up then. I have had the radiator out and cleaned about a year or so ago as it did start to heat up all of a sudden, was sweet as after the rod/clean

Check the restriction valve for being stuck closed?

Ok. What or where is that? Is that the same valve as the bypass?

The restriction valve is located in the steel line at the bottom of the oil cooler. There is a hose that connects the line to the cooler. The restriction valve just slides up into the steel line.

Ok thanks. I'll look into that. The other issue tho that dosen't fit with that is the machine lacks hydraulic performance. It dosen't dig & walk up hill like a digger with a brand new pump. That valve won't affect performance will it?

Any unusual noises like whining or cavitation? Suction screen in the tank been checked? Integrity of the suction hose to the pump? Has the pilot pressures been checked? Has the pilot pressure at the spools on the control valve been checked? How about the control pressures from the pump control valves, have they been checked? Did your Hitachi tech check for codes with MPDr? Did he make sure all the pressure sensors are working? Hopefully someone with more Hitachi experience will chime in??

So no unusual noises, suction screen good, hose to pump appears good, pilot pressures checked, not sure about pilot pressures at control valve and control pressures from pump control valves . Pressure sensors are all working correctly, he has had the laptop plugged into it several times and it says everything is good

Well, I'm late on this thread so correct me if I am wrong, but has the engine performance been checked? The heating issue may be a totally separate issue but I would think that the engine speeds (high idle no load, high idle stall load, etc....) should be verified and within specs. Just throwing some ideas around at the moment.

A main relief valve set to low or one bypassing partial flow without opening would make heat and kill performance. In your case is find some accurate ways to take hydraulic temp and watch them from cab while running to see where the heats being produced or where it's not being dissipated I've never found a non contact temp gun that will give accurate readings for hydraulic or a/c but do have better luck with engine cooling systems go figure

Thanks so much guys for the input, any ideas are appreciated. Vetech yes the engine pulls the correct revs with the pump set to spec and under load so am sure its not a problem with the engine. So the main relief is something I have questioned them about several times. They tell me its good. Do you think I should put another one in to be 100% sure? I have played with a heat gun but like you say I couldn't get any consistency with it . Then Hitachi brought down a thermal imaging gun. I spent quite a while with it. Things were getting bloody hot but couldn't really pinpoint anything. By memory the top of the valve bank was bloody hot and the oil getting back to the tank was like 120 degrees plus or something. I think the oil temperature on the machine is taken from the bottom of the tank where its at it's coolest, in reality it gets far hotter. Just to reiterate the valve bank was removed and fully resealed at the beginning of the year

The only thing I have left (for performance, not overheating) is the speed sensor. Has that been checked for accuracy? An erroneous reading could fool the PVC into thinking the engine is pulling down too far and then the PVC activates the torque control solenoid destroking the pumps. Or the torque control solenoid is bad allowing destroke of the pumps. Other than that you need to get your Hitachi guy back out there. Something was missed on the original diagnostics.

If the torque solenoid was disconnected would that give me a true idea of how its performing at full revs and load?

You can try it. That will prevent it from activating electrically, but if the spool inside is stuck it will not change anything.

Ok. We did swap the solenoid over with a spare from another function that is not in service, made no difference

Sorry Huffa, that's all I have. Time to get the Hitachi guy back out.

Hey I appreciate all the input. Surely I cant be the only guy on the planet thats had this happen to a 160! Yea Hitachi guy coming back soon but hes basically out of ideas

Huffa said:Hey I appreciate all the input. Surely I cant be the only guy on the planet thats had this happen to a 160! Yea Hitachi guy coming back soon but hes basically out of ideasClick to expand...This time have your Hitachi guy give you hard data and start with your engine performance 1st. The more specific data you can provide the easier this will be to troubleshoot. We need high idle rpm, hydraulic stall and full stall rpms, specific pressure reading numbers.....and preferably, for me anyways,....in US standard. LOL

Will do thanks

Vetech63 said:This time have your Hitachi guy give you hard data and start with your engine performance 1st. The more specific data you can provide the easier this will be to troubleshoot. We need high idle rpm, hydraulic stall and full stall rpms, specific pressure reading numbers.....and preferably, for me anyways,....in US standard. LOLClick to expand...I've been reading along with this thread and was thinking along the same lines. My comment to the Hitachi tech would be along the lines of - if everything with the engine is allegedly "OK" or "within spec" then give me some numbers FFS...…..!!

Nige said:I've been reading along with this thread and was thinking along the same lines. My comment to the Hitachi tech would be along the lines of - if everything with the engine is allegedly "OK" or "within spec" then give me some numbers FFS...…..!!Click to expand...Yeah, I've been in this business long enough to know that every time I assume something, it bites me in the ass. Just because something is working doesn't mean it is working properly. Without hard numbers this is all just a crapshoot.

Someone told me long ago that if you everASS U MEit will end up making anASSout of bothUandME.Not much sticks with me but that one did ………….

Huffa said:Will do thanksClick to expand...I suggest starting all over from the beginning. I'll bet (since this has been going on for 2 years) that you and your tech have gotten tunnel vision and are overlooking something...……..yes, we all have done it so don't feel bad.Start with your engine first! It is the power that drives your hydraulic system and weak performance will directly effect your hydraulics. Register full high idle rpms and do they meet the manufacturers specs? Hydraulic stall specs? Full stall if applicable? When under stall, do you see exhaust smoke? What color is it? does it seem excessive? Can your hear the turbocharger wind up? Until all of your engine parameters are met, you are wasting your time testing anything hydraulically.If the engine checks out, then move to the hydraulic portion and start with your pump system. The pump not only creates pressure, but creates flow. Is your hydraulics slow?...or no power?....or both? Run the machine through each function and take notice as to whether there are any noises? Do all the functions have the same symptom? Are they all slow with no power?.....or do other functions seem normal and others dont?Although a main pressure test may see relief pressure, your flow may be down which would cause the hydraulics to be slow. Does the main pressure relief meet specs? What is the pressure reading? Is the main pressure reading the same with each function? Is there any unusual noises when the relief is open (outside of the normal sound of a relief)? The best way to determine pump condition would be the use of a flow meter. Your Hitachi guy should have one, and should have all the specs for the pump.................I would do this FIRST thing Hydraulically. If you dont, the system could have you chasing your tail.If your pump checks out, then its control valve time. Check the above engine and pump out. If those check out with real data info posted here, then we can move on to more troubleshooting.There is plenty of knowlege here to help you get most problems figured out........But we need real and specific data and information to get anywhere.

Nige said:Someone told me long ago that if you everASS U MEit will end up making anASSout of bothUandME.Not much sticks with me but that one did ………….Click to expand...LOL....that's a GREAT 1!

Nige said:Someone told me long ago that if you everASS U MEit will end up making anASSout of bothUandME.Not much sticks with me but that one did ………….Click to expand...LOL....that's a GREAT 1!

Thank you guys. The technician is coming to take function cycle speeds. Something to do with product support requirement. Just to recap re engine, with the hydraulic pump set to the factory specs the engine pulls the correct revs under load 2150-2200rpm I think it is in H/P mode. So if it's pulling the correct revs with full load how could it be an engine/power issue? The engine doesn't sound like its working hard, it's like the pump isn't loading it up fully. They have flow tested the pump twice, that was on the old pump and it pissed in, new pump hasn't been flowed. I'll try and get some hard data from the technician

I had similar problems with my komatsu 150-6 I tried everything, finally I put a new main relief valve in and it runs like brand new! Worth a shot!

Far out! I have questioned the main relief to them from the start. They tell me they have checked it and its good, but can you actually test them properly or do you just have to replace it to be sure? How did you come to the conclusion with yours?

I pulled mine out when I first started having problems but all looked good and clean to me, even though I didn’t really know what I was looking at so I tried all kinds of things to try to fix my problems new hydro oil, new turbo, new solenoids and so on with no luck at all, so finally I said what the hell i will buy a new main relief valve and so I put it in and the machine has ran like new since ! I couldn’t believe it! I’m not saying it’s your problem but for the cost it’s worth a shot I think I paid like $250 for mine and man I wish I would of tried it first because it would have saved me lots of time and money!

Did you notice hydraulic temp rising with crook relief?

Yeah it was definitely getting warm I never made note of actual temp but it was well above what it should of been, seeing that you replaced the pump and all major components I couldn’t see what else it would be other than the main relief

Ordered new main relief, over $800 unfortunately for genuine, couldn't seem to find anything aftermarket, worth a go, thanks for the input

I've ordered a main relief, couldn't find an aftermarket had to go genuine, over $800 unfortunately, fingers crossed

Hi Huffa, have got similar problem with a zx160. Did you diagnose what was wrong with yours, I know that was sometime ago.

Hi there. No never got to ghe bottom of ir sorry. Still have it still a pig

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