New Holland L785 issue

[dalaplant]

Hello,

I recently acquired a New Holland 785 (1992 model) skid Steer. I don't know much about its past since I bought it at auction. What I do know is when I bought it had a bad hydraulic leak (turned out to be the filter seal was out of place). I replaced it and the leak was gone so I drove it slowly off the trailer. Once on the ground I added some hydraulic oil (a Kubota brand hydrostatic trans / hydraulic oil) to get the level back up to the dip stick low mark. I filled it through the dipstick hole since it was about an inch in diameter and I could get a funnel in there. Now it doesn't leak but also doesn’t seem to work well. I drove it off the trailer and that’s about as far as it went really. What I've found is if I start it and keep the engine at idle things kind of work, it moves (moves a noise like the pumo is working hard, like it would at the end of a cylinder range), the bucket goes up slowly and the pivots slowly, but if I turn up the RPM's it stops moving and stops operating the bucket. As you can tell I’m pretty new to the Skid Steer world so I’m not sure where to go next with this issue. Any advice about things I could check would be greatly appreciated.

Thanks.
Doug

 

[Squizzy246B]

G,day Doug, Welcome, not a lot to go on but it sounds like the system is running out of oil. Its worth worth checking out the safety devices which normally apply the brakes and prevent the loader from operating when you are not in the seat. They may be defective and are preventing operation.

Then I'd replace the hydraulic filter, it could be well blocked or the wrong type. After that, and if you have a manual it helps but there is normally a strainer on the hydraulic pick up in the hydraulic tank. Pull that out and replace the cartridge or clean it depending on what type it is.

After that I'd give her a good degreasing and cleanup then call your local NH/Case or even Deere dealer and get them to test the hydraulic pump output. May as well start at the start.

Good Luck, I'm no NH expert but I'm sure there is others here who can be more helpful.

 

[Jeff D.]

Does it have a warning light for loss of pressure in the hydraulic system?If so,I'd be very careful to run it as little as possible,if it's on.The hydrostatic drive pump (not the driven motors)are often feed by the hydraulic pump,and without the fluid being fed to it,the hydrostatic pump can burn up very quickly.They are prone too failure from loss of feed line pressure MUCH more so than hydraulic pumps are..Although the hydrostatic pump may not be driving the wheels they still need that positive flow of fluid all the time from the hydraulic pump.

Squizzy's advice about checking the safety interlock system is a good place to start.That could explain the problem.I don't think simply putting the incorrect fluid in it could have caused this problem,unless it was VERY heavy,like 90w grease.It wouldn't help it for longevity,but it shouldn't cause this much problems.

Otherwise,since both the hydraulic and hydrostatic systems seem to be affected,I'd look at a blockage to the supply to the hydraulic pump.(between reservior tank and pump,and common to both systems)The hydrostatic system will operate with low fed pressure(about 25psi)with almost unchanged performance.But it will be destroyed with no feed pressure.Since there is usually seperate paths for the fluid return from both systems,and the filter is usually in line to the feed of the hydrostatic pump,a blockage in the other lines probably wouldn't affect both systems.Although the line from the hydraulic pump to the main control valve section would cause the problem.The hydrostatic is usually a "T" off after this valve.A system relief valve stuck open could cause the problem also,but most likely you'de have enough pressure for the drive to work correctly.A plugged filter most likely wouldn't cause the problem,as the are usually plumbed in the system were all the fluid isn't passing through it at any time,and they have a bypass in case they do plug.

The only other thing I can think of,since you've no external leaks now,and the fluid is full,is a failed hydraulic pump.This is much cheaper than a hydrostatic pump,and since they both depend on this pump I'd be wary of running the machine any more than absolutely necessary.If you have a light for system pressure,and it's working I'd go by that.No pressure/no run.What concerns me,by your post,is the mention of a sound like the pump is working hard,but nothings moving.The hydrostatic pump will make a "Wwwrrrr"sound when it's starving for fluid.I was told by the hydraulic shop that a hydrostat can be ruined after as little as 20 seconds of running without supply pressure & fluid.I learned all this stuff the hard way,believe me!!

Good Luck.

 

[CGSI]

Hello,

I recently acquired a New Holland 785 (1992 model) skid Steer. I don't know much about its past since I bought it at auction. What I do know is when I bought it had a bad hydraulic leak (turned out to be the filter seal was out of place). I replaced it and the leak was gone so I drove it slowly off the trailer. Once on the ground I added some hydraulic oil (a Kubota brand hydrostatic trans / hydraulic oil) to get the level back up to the dip stick low mark. I filled it through the dipstick hole since it was about an inch in diameter and I could get a funnel in there. Now it doesn't leak but also doesn’t seem to work well. I drove it off the trailer and that’s about as far as it went really. What I've found is if I start it and keep the engine at idle things kind of work, it moves (moves a noise like the pumo is working hard, like it would at the end of a cylinder range), the bucket goes up slowly and the pivots slowly, but if I turn up the RPM's it stops moving and stops operating the bucket. As you can tell I’m pretty new to the Skid Steer world so I’m not sure where to go next with this issue. Any advice about things I could check would be greatly appreciated.

Thanks.
Doug

Doug
i have a NH Lx565 and for hydraulic oil mine calls for 10W30 Motor oil type SF/CD. if yours takes the same and you have added a hydraulic oil you may be causing your own problems. the first thing i would do is find out what oil belongs in it and if it is the same as mine, drain it immediatley and get it changed. hopefully if your oil is wrong you have done no irreversable damage.

 

[dalaplant]

Hello again all,

Thanks for the great advice. After hearing about the pick-up filter I got with the dealer to get a few pages faxed from the manual (I've since ordered one for the machine to have) and found the filter. I opened it up low and behold plugged completely up. I cleaned it up good, put it back in and away I went...

What a relief the pump isn't shot!!

I did run into an issue though, after running around for about 10 or 15 minutes the bucket tilt and raise functions slowed way down again. I think I know what it is since I checked the fluid and it was white as milk, I've been told that’s a sign of water in the system. After the leak I added about 10 gallons to get it to level but I understand it holds about 22 gallons. So it out with the old fluid and replace it all. By the way when I moved it into the shop the functions never slowed down even though I did move it around a while. I figure the water must have settled in the tanks and thus left just fluid in the lines.

This leads me to a question, will draining the tanks and filters be good or should I take steps to drain the system (lines, pump)? If so how do I do that?

And lastly, the tires on it are pretty rough (and a couple have slow leaks) so I'm planning to put new on. There are some cheaper tires on ebay that should get me by. My question is this: The rims are dented up, pretty good in a couple places, but still drive straight. Will I be able to mount new tires on them or will they need to be replaced?


Thanks Again for all the help, I'm looking forward to posting more and reading the forum.

 

[Jeff D.]

What a relief that it isn't something major!!:yup

I would try and get all the fluid changed out,but don't really know how you'de do it either,besides disassembiling all the line connections.Might have too change it out a couple of times,and run it,too get it all.

BTW,I had an old farmall H that got water in the tranny.Musta got in from sitting outside,somehow?? I found out once winter came,and the thing wouldn't move.Locked the tranny solid.I was relieved once I found out it was water.A couple of hours with the reddy heater,and I atleast got it thawed out enough to drain.Had a good gallon or two of water in it!!

As for the dented rims,I guess it would depend on how badly they're dented.If they're not so bad that they cause leaks,and don't look like there's any cracking,I'd probably try and continue running them.

Good luck with your new "toys"

 

[CGSI]

This leads me to a question, will draining the tanks and filters be good or should I take steps to drain the system (lines, pump)? If so how do I do that?

And lastly, the tires on it are pretty rough (and a couple have slow leaks) so I'm planning to put new on. There are some cheaper tires on ebay that should get me by. My question is this: The rims are dented up, pretty good in a couple places, but still drive straight. Will I be able to mount new tires on them or will they need to be replaced?


Thanks Again for all the help, I'm looking forward to posting more and reading the forum.[/QUOTE]



Doug
Glad to hear the pump is OK. i would make sure the oil is full and run it around and get the oils good and hot and change the filters and fluid one nore time real quick to get that moisture out of the system. If you don't get it out you will be looking for problems. Some of the issue could be mixed oils too making it look bad. Drain it out hot and refill again then keep an eyen on it and see if it stays clear. with all the pump and hydraulic lines on the machine it may take you a few oil changes but the money spent now is better than the results of not getting it out.:nono

 

[Squizzy246B]

Doug, I am the master of bent rims. If the whole rim is not out of round, just dented then get a big shifting spanner, a good dolly (4lb hammer) and go to work (with the tyre off of course). The shifting spanner can be fitted to the bead lip and used to bend the rim back into place...followed by a couple a good wallops with the dolly to get things in line. Dress out any sharp edges with a file or die grinder and your in business. Its not that harder and skids don't do 60 mph.

I have taken a number of dings out of my rims and have no problem although I do run tubes in my tyres.

Back with the hydraulics I'd say your Hyd oil tank is full of crap and it needs a good flush in situ or pulling out if possible. I'd drop the oil out immediatley and clean the pickup again and try and have a look in the tank. Could be big problems that changing oil and filters wont cure in a hurry.

If the tank is clean then go ahead and cycle the machine and do a couple of changes with say 5 hours running between.

 

[dalaplant]

Well looks a good flush was the trick.

I ended up draining the oil and then thought about how I could get as much crud as possible out if the tanks so I used a window screen doubled up over a bucket and filter the oils that I took out and then dumped them back in and drained the "filtered oil" back out, it worked pretty good I did this a few times it really did get some more crub out od there. After that the tanks looked pretty good so I put new fluid in (got the manuall so I know now its a "J20A" spec fluid, not that I know what that is, but the guy selling the oil did.)

I've run the machine for a bit now and the problem hasn't come back. I'm still planning to clean the filter the next few times I run it but it looks good so far.

Thank you all again for the input, I'm glad I got the thing its been fun working on it and learning more about how these things work.

Doug

 

[CGSI]

Well looks a good flush was the trick.

I ended up draining the oil and then thought about how I could get as much crud as possible out if the tanks so I used a window screen doubled up over a bucket and filter the oils that I took out and then dumped them back in and drained the "filtered oil" back out, it worked pretty good I did this a few times it really did get some more crub out od there. After that the tanks looked pretty good so I put new fluid in (got the manuall so I know now its a "J20A" spec fluid, not that I know what that is, but the guy selling the oil did.)

I've run the machine for a bit now and the problem hasn't come back. I'm still planning to clean the filter the next few times I run it but it looks good so far.

Thank you all again for the input, I'm glad I got the thing its been fun working on it and learning more about how these things work.

Doug

Doug
Glad it all worked out. Thats what these forums are all about. Each of us sharing the knowledge that we have and helping each other.

 

[Squizzy246B]

Doug, thats great but may not be the end of your problem. If a hydraulic tank has a lot of sludge in it that means crap has been getting into it over a long period of time and is generally due to a defect in the system. Check the filler cap seal and then locate the breather. The system breather is often inside the filler cap but is sometimes fitted to the end of a small hose. The breather comes off and the system sucks dust. Wash the breather out with gasoline (if its actually there), turps or whatever the manual says.

Have you actually been able to see inside the Hyd tank...like with a torch and mirror...there could still be mobs of crap in there.

Lastly, if the person who owned the machine before had this much respect for the hydraulic system you have to wonder what your drive chains and sumps are like.

Good Luck.

 

[digger242j]

like with a torch and mirror...there could still be mobs of crap in there.

IMPORTANT NOTE: By "torch", Squizzy means "flashlight". Don't go sticking anything in there that's on fire! (Usually Squizzy speaks American pretty good, so I guess we can forgive him this time...)

 

[Squizzy246B]

IMPORTANT NOTE: By "torch", Squizzy means "flashlight". Don't go sticking anything in there that's on fire! (Usually Squizzy speaks American pretty good, so I guess we can forgive him this time...)

..Ok thanks digger...that one slipped through :notworthy
but in all seriousness...I wouldn't even see the mushroom cloud from here

Please forgive my indescretion at the risk of serious personal injury.

but thats what you got for dealing with a bunch of people that call a liquid "gas".

Thanks.

 

[CGSI]

IMPORTANT NOTE: By "torch", Squizzy means "flashlight". Don't go sticking anything in there that's on fire! (Usually Squizzy speaks American pretty good, so I guess we can forgive him this time...)

Good Catch Digger:notworthy
I am used to Aussie's, Kiwi's and Britts. Good think you mentioned that though or somebody might be suing Squizzy and then where would we all be.:Banghead

 

[digger242j]

Well, I knew all our members would be smart enough to think twice about that, but if you look at "Currently Active Users"--that fellow "guest" who's always reading the threads--we don't know how smart he is...

 

[Squizzy246B]

Well, I knew all our members would be smart enough to think twice about that, but if you look at "Currently Active Users"--that fellow "guest" who's always reading the threads--we don't know how smart he is...

Lets face it if he was smart he'd...nah!..better leave it at that

 

[digger242j]

Lets face it if he was smart he'd...nah!..better leave it at that

Well, it's a scientifically proven fact theat just becoming a member here increases your IQ by 10 points, automatically. (Being a moderator gets you 15 points--mine went from 61 right up to 73...) :thumbsup

 

[Squizzy246B]

Well, it's a scientifically proven fact theat just becoming a member here increases your IQ by 10 points, automatically. (Being a moderator gets you 15 points--mine went from 61 right up to 73...) :thumbsup

Ok hand over the controls then, I need all I can get

adde parvum parvo magnus acervus erit

 

[xkvator]

IMPORTANT NOTE: By "torch", Squizzy means "flashlight". Don't go sticking anything in there that's on fire! (Usually Squizzy speaks American pretty good, so I guess we can forgive him this time...)

Too Late !!!

 

[Squizzy246B]

That puddy Tat needs a paint job.