I have access to several hundred gallons of clean/used hydraulic oil . I know some people who mix tranny fluid up to 50% in their trucks after heavy filtering without any problems. I also know alot of people who do the straight vegetable oil fuel in their diesels. Anyone know of any reason I couldn't use hydraulic oil if it was properly filtered. The only concern I have heard so far is that it might burn completely , but others say it would. If I added a N20 or propane system to my truck I would imagine that would help get a more complete burn. Any thoughts or comments welcome............Thanks .

 

used hydraulic oil contains water, very fine metal wear particles, and some soft goods(o-rings, wipers, seals, etc). with 10 micron fuel filters installed in these newer trucks and still having injector problems due to contaminates, I wouldnt in my truck. but that is just me. filtering needs to be more than just a spin on filter. Here at work, we use a filterdyne machine, that pulls the oil out of the tank at 26" hg, heats it to 150*(those 2 processes boil the moisture out) then the oil goes through at 10 and 2 micron filter assembly before going back to the crane reservoir. then it is clean.

 

First off be sure that it is petro based and not mineral/water. The later will not burn.
I am not so sure that there is much for lubricity in Hydraulic oil so I would surely say some sort of additive is in order. Filter it well starting with 10 mic and work your way down to 2 or even .5 if you can find the filters in your area. Then run it through a good (recor etc..) water seperating filter. How you can get rid of moisture at 150* is beyond me as water gases at 212* and be very careful as the flash point of some hydraulic oils are around 225* give or take. From there you should be fine but do so at your own risk. Diesel flashes at

 

did you notice the 26" hg part? that means vacuum. water at 28"hg boils at 78*. I used to do commercial airconditioning and refrigeration, you have to run a vacuum before recharging to remove all AIR and MOISTURE. Now I do hydraulic cranes and you HAVE to run a vacuum and heat to remove moisture. You dont want to heat up oil above 212*, because you burn it. then the lubricating properties are altered and now you've ruined pumps and motors. It is rare that I will make a statement in a post without knowing what I am talking about. So it may be beyond you, but maybe it is not what you do for a living. have a good day.

 

Relax studly! Didn't mean it to be a jab st your level of knowledge. Simply stated that it was beyond me (my understanding). Glad you came back and clarified. Sorry I'm not super mechanic. Hope your day is good as well

 

Thanks, that's all good info. I'm not too worried about the filtration. I would setup my own filtration and filter to at least 1 micron or more if I can. The water issue might be a little bit of an issue as I can't setup a system to pull vaccuum at that level. However, if I heat the oil and let it set for a couple weeks I would think the water would separate. I am fairly certain the oil is petroleum based (mobil DTE 25, i think). Do you think the hyd oil would burn OK and not leave any residue? It's not a big deal to add a quart of diesel additive to the tank with the hyd/diesel mix for extra lubrication. Although it sounds appealing to try, perhaps it's not worth the risk if there isn't enough research/testing to support it as an alternative fuel. I'll do a little more research and see if any more details on the subject show up. Thanks

 

foamdoc - what engine are you wanting to run the hydraulic oil in?

 

I immediately thought the same thing - "it's under a VACUUM!" , but just as quickly realized CSAGrey1 doesn't have the same skillset/experiences as we do... I know it can be frustrating sometimes to deal with people who don't understand what you're talking about.
I don't think he was impugning your street cred or anything - he just flat didn't know!
I'm curious where your 212* figure for "burning oil" comes from; is that for hydraulic oil in particular?

 

It's OK!
Those of us in the service sector are usually techs because we enjoy fixing things, troubleshooting and just generally helping others out of jams, but we sometimes get impatient with people who seem to discount or ignore our hard-won years of training & experience; I mean - this is how we feed our families!
Many of us take pride in our work and the knowledge we've accrued, which helps us overlook how often we're taken for granted or unappreciated by those who we serve.
It's not easy being a "super mechanic"!

 

here we use rando hd 46 and mobil dte 26. the 46 will "burn" about 200*. by burn I mean to start changing properties. Hyd oil will burn. The water content should not be an issue. the only reason we remove moisture is for corrosion and acid forming. you are planning to burn it, it should be gone quickly,not sit in the system for 1 year inbetween filtering.

and you are correct. I did get slightly hostile with senor grey and should not have. I gave a reputation point for being a good person as to reply without increasing the confrontation. He is ok in my tiny little book.

 

I just gave ya posrepoint for being a class act

 

XLR8R,

Sorry, been busy and not checky my posts regularly. To answer your question, I am wanting to run it in sig diesel ('99 2500).

I'm not too conerned about water, the oil I would get should be water free, but I'm sure I could filter it out with a seperator if needed.
So far one of the only concerns I have heard from many (other than making sure to do additional filtering) is that hyd oil might leave more carbon deposits in the chamber. Not sure about this, but was wondering if water/meth, hydrogen, or propane injection would help keep the motor clean. And of course the added HP would be OK too.

 

Just stay away from acidic oil and detergent-laden oil.

 

I have some test results for the hyd oil we have in our systems that I would be using. Here are the big hitters in the results in PPM:

Calcium 60-75
Phosphorus 300-370
zinc 525-700

Most other components/comtaminants were only 1-3 PPM.....Like lead, copper,iron, sodium, magnesium, etc. Results showed 0% water content. The results are from an independant lab we send samples to regularly to check for oil quality. Does anything here pose any concerns? Thanks!

 

Zinc rings a bell for being undesirable, though I don't recollect the exact numbers... I bet Oil Guy knows, there was a recent thread that mentioned it.