Still more D-250 questions

[6wheeler 603]

I need a little more help with the beast. Can anyone tell me how to change the hydraulic oil on this critter? My computer is down right now. So, I have to use this tablet right now and cannot download the manuals. Because, just like the user? It has very limited memory. And with only the use of one arm at this time, I will have to have Mama do it. Anyway,does it have a filter? It looks as though, it could be in the rear of the pump itself. But, I could be wrong (like that hasn't happened before). How do we drain the oil from the tank? And, last but not least? Can I use universal hydraulic fluid instead of 10wt. engine oil in this system? Questions, Questions... Any help would be appreciated. Thanks Pat

[stratostar250 919]

I'm am quite sure that there is no filter in the system.  I remember reading that someone was working on their D250 and that they were surprised that they didn't have a filter.  I hope someone else can chime in, because I have wanted to change mine as well, and I was going to use the 10W oil, but the oil is near IMPOSSIBLE to find.  The only oil I've found that exists with API SC classification (which is what is required) is called Mobil Hydraulic 10W, and they only sell it in 5 Gal containers for a good sum of money and I cannot justify buying it just to maybe use a few quarts.

Edited May 6, 2015 by stratostar250

[blu_stang 14]

I recently changed the hydraulic fluid on my D250.  Mine is a'76 with the single action system.  Supposedly, there is a filter cartridge in the pump reservoir, but I was not able to get the reservoir off the back of my pump unit, to get to it.  The pump reservoir is the can that sits on the back of the pump, itself, not the overflow tank up in the grill.   I too had difficulty finding the straight weight 10W oil, so I chose to take a chance on the Traveller Universal Hydraulic Oil at Tractor Supply.  It is rated for use in many of the top brands for current models, and has a viscosity rating of  either 10W-20 or 10W-30 (depending on which container size description you read) .  So, it is multi-viscosity, but it's pretty close to what was original spec.  It was about $40 for a 5 gallon container.  

 

I also have what is a custom fit loader on my tractor (Johnson Workhorse model 14, I think),  which has a separate pump and reservoir for it's double action system.  That manual calls for SAE 10W-40.  I am using the same Traveller fluid in that loop.  I switched to the one hydraulic fluid also because I was not sure what the previous owner had been using in either, so I flushed and refilled.

 

I drained my hydraulic system by following the instructions in the repair manual, available in the manuals section of this forum (chapter 8).  But basically, you unscrew the hose connection from the top of the reservoir, unscrew the plug closer to the pump and let the hose drain out.  Refill and allow the system to bleed by filling the top of the reservoir running the hydraulic lift, refill, run lift, and so on, until the air is let out.  You may also want to drain the fluid from your lift cylinder by unscrewing that hose connection, as well.  So far the pump and lift have been working just fine with about 10 hours on it since the fluid change.

 

By the way, I am far from being a hydraulics expert, but given the close viscosity and known ratings for that fluid, I was willing to give it a try.  Call it an educated guess from a weekend mechanic with a degree in engineering.   If there are any hydraulics experts that can chime in I would love to know if they think I've made a hydraulics "faux pas".  

[6wheeler 603]

I had a chat with our main hydraulics guy at work. He said that in this system universal hydraulic fluid would be fine. The reason companies like Bosch used 10wt oil was because there was no universal type fluid back then. IE; John Deere and International, Allis Chalmers, Cat and the like each exclusively had their own fluids. According to him, Mobil Oil was first with their 423 universal hydraulic fluid. The problem was, and still is? Flow ability in colder climates. Along with the ability to handle high heat without flashing. He said,"what's the worse that could happen, smoke the pump"? Then he laughed. "It won't". So, I am trying it.