Skidder hydraulics overheating

[rhodap]

 I run a 748h 2014 jd grapple skidder and recently I ran my hydraulics dry when I noticed I added oil and afterwards my hydraulic oil temp Kees going way way up! What is wrong? I thought the valve was stuck but Im thinking pump now idk anyone know more about this ?

[barbender]

Running your pump dry is usually very bad news!

[kiko]

Does the engine load more than normal,  and if so does seem to release when ever a hydraulic function is moving? This would be more noticeable at low throttle.

[charles mann]

I know it isnt a skidder, but when we were working the bugs out of an internal tank in our helicopter. We noticed over 5 pump replacements, our utility hyd temps would be at the high side of the normal operating temp range several days preceding the pump failures. Only 2x did we loose fluid and cavitate the pump on the aft xmsn before getting the engs shut down amd rotors stopped. The other 3 pump failures were on the apu and we contributed the failures to a fluid volume requirement at max or just beyond max if we were running any other hyd systems in conjunction with the tank hyd system. 

It could be you cavitated your pump and its starting to eat itself. 

As kiko asked, are you noticing the eng bogging down when hyd are in use? 

Does the skidder hyd have a cooler and is the fan a stand alone or the eng fan to pull the air through? 

If it has a cooler, are you getting good fluid flow, cooling fins clogged? 

[rhodap]

No the engine isn't different at all the only thing that happens is I start getting a warning light that says hydraulic oil over temp and it's been as high as 213 F
Which I know is hotter than any summer temp I've ever seen! 
We changed the filters, but one thing happened yesterday,, I ran it for about half hour then it started giving me the temp warning. I had to cool down engine and turn off machine as hyd temp doesn't go down if it's at idle it has to be off. So I sat for fifteen mins then fired it back up and ran until I seen warning. 
After an hour I tried it again... I ran all day without another warning. I'm thinking there is water in my hyd tank and when it's cold it's ice plugging something and after it's hot enough to melt ice it runs fine. Now how do I get water out without draining the whole system. Boss doesn't want to it's -40 here right now!... 

[rhodap]

Also the reason I'm thinking there could be water is a past employee ran my skidder without a hydraulic tank cap on for quite awhile as in weeks. So I'm the summer possibly water got into tank and now that it's winter I'm seeking the aftermath... 

[barbender]

That tidbit about the missing hydraulic cap is the sort of thing that drives service techs insane. They could've done troubleshooting on your machine all day, with nothing making sense until you told them that the system likely ingested water. That completely changes the situation, you need to get it warm and drain it down.

[Andries]

. . .  you need to get it warm and drain it down.

Water in the hydraulic system, then add -40° equals a dead machine. In hindsight, you're lucky. The machine still runs. It still fix-able.
Strike one: water in the hyd oil.
Strike two: running out of hyd oil.
Strike three: that's up to you.
That 'past employee' cost you a complete change of hyd oil and filters and the time to do it. 
Could be why he's a 'past' employee?
Times two what barbender recommended. 👍

[OntarioAl]

Run the machine all summer without a cap on the hydraulic tank
Ahhhhhhh !!!!! and your boss doesn't want to shut down because its minus 40
Easy you build a temporary tarp structure and heat it with a construction type propane fuel heater 
Its not going to improve only cause more $$ troubles
Pay me now or pay me later
Like barbender says you left out a very importin tidbit when you first posted
Cheers
Al

[barbender]

We had two forwarders on one job. Young guy called me and said his engine died. So I went over to give him a hand. He said that when his machine was parked during spring break up, a mechanic had left the fuel cap off and it sat like that for a couple of months. 

 So I pulled the water separator off, and thawed it out in front of the preheater exhaust. Thawed and drained, I reinstalled it (I didn't have a spare with) and got the fuel system bled. Got the Mercedes fired back up. I told him that he needed to drain his water separator at the end of the day, when the machine was warmed up and it was thawed out or he'd be in the same situation in the morning. Also, I should mention it was about -15°F, nice weather to be getting fuel on your hands. 

 At the end of the day, did he drain his water separator? No, he didn't. Did I help him again when he was froze up again the next day? No, I did not😑