Oil & Fuel Bypass oil filter for those that care

[SpringHollow]

You can find used ones on Ebay for fairly reasonable prices. You can save even more by building your own with a used pump.

Ken

 

[ponytug]

Speaking of used pumps, I wonder if a used power steering pump would work. Basically, we don't need a lot of pressure, just enough to move things over the filters.

Plus a steering pump plus V belts would give one the chance to optimize the performance of the pump.

What am I missing?

Just thinking out loud...

All the best,

Peter

 

[SpringHollow]

On on board "filter cart" could easily be made with a 12V pump if you only ran it when the oil was warm. It is the cold oil that requires a powerful pump. Hard to find room for it though. Seems like this would be much simpler than the steering pump.

If there was a cheap dependable bypass setup where only say 15 psi went to the filter and the rest did not create a significant back pressure on the pump making it work hard, the PTO filter would make some sense.

Ken

 

[Clarke]

http://www.tractorbynet.com/forums/power-trac/105102-inexpensive-filter-cart.html

 

[SpringHollow]

I never saw that post - how well does that pump work with cold oil? The thermal protection on my used tuthill pump sometimes kicks in when the temps are below 20. This winter, it will be in a heated area (50), so it should not be an issue.

Did you ever do the quick disconnect setup? I used some 3/4 flat face fittings on mine. One could even use o-ring seal hydraulic fittings with female caps for when it is not being used.

Ken

 

[KentT]

I think the simplest solution is to adapt a high-pressure filter (with a bypass) to connect to the front PTO. 8 GPM (or 12 GPM or more, on the larger PTs) and it wouldn't take long to circulate all your oil through it, even though the filtered oil is dumping back into the tank and mixing with the unfiltered oil. I'm not a mathematician, but it seems like 10 to 15 minutes of run time occasionally, and you'd have well filtered oil...

 

[smartguyz]

http://www.tractorbynet.com/forums/power-trac/105102-inexpensive-filter-cart.html

Hey Clarke - just what I was looking for... Can you give us a little more detailed breakout and better pictures? Thanks so much!

-Rob

 

[ponytug]

And the prize for shirt cuff calculation in ball parking the right number goes to... Envelope please, KenT!

The math is pretty straightforward, if you don't split nits. Each minute filters a fraction R of the tank, leaving 1-R unfiltered. Each subsequent minute filters that ratio again, giving the amount of unfiltered oil as (1-R)*(1-R) and then

(1-R)*(1-R)...(1-R)

Or

(1-R)**N is the amount of unfiltered oil after N minutes. i.e. if y= is the fraction unfiltered oil, then
y=(1-R)**N
or
log=Nlog(1-R)
or
N=log/log(1-R)

For a PTO running at 12gpm for a 40gallon tank, it takes a little less than 20 minutes to get to less than 0.1% filtered, running at wide open throttle. Mathematical nitpicking would push the number closer to 25 minutes. (Hint think APY.)

Now WOT might require warm oil, but the math is unchanged unless the relief kicks in.

All of which lead me to wonder about the utility of doing this offline...

All the best,

Peter

I think the simplest solution is to adapt a high-pressure filter (with a bypass) to connect to the front PTO. 8 GPM (or 12 GPM or more, on the larger PTs) and it wouldn't take long to circulate all your oil through it, even though the filtered oil is dumping back into the tank and mixing with the unfiltered oil. I'm not a mathematician, but it seems like 10 to 15 minutes of run time occasionally, and you'd have well filtered oil...

 

[SpringHollow]

You need an affordable, reliable bypass setup that can handle the full flow and pressure of the PT and yet have a low enough relief setting to not destroy the filter. Maybe I am always looking in the wrong places but I have not found one. Surplus has one with the low end relief adjustable down to 125. Maybe then put a lower pressure one after that that can get down to the filter range? I am starting to get nervous already. Any idea what the pressure would be midline in the run when the PTO is in full bypass. The flows are so high i bet it is close to, if not above, the filter rating (media, not the can) even though the end of the line is open. If that is true, then you would need to run a separate return line back to the tank.

Or am I thinking about this all wrong?

Ken

 

[KentT]

You need an affordable, reliable bypass setup that can handle the full flow and pressure of the PT and yet have a low enough relief setting to not destroy the filter. Maybe I am always looking in the wrong places but I have not found one. Surplus has one with the low end relief adjustable down to 125. Maybe then put a lower pressure one after that that can get down to the filter range? I am starting to get nervous already. Any idea what the pressure would be midline in the run when the PTO is in full bypass. The flows are so high i bet it is close to, if not above, the filter rating (media, not the can) even though the end of the line is open. If that is true, then you would need to run a separate return line back to the tank.

Or am I thinking about this all wrong?

Ken

I don't know if these would qualify as "affordable", but this brand has filters that can handle up to 6,000 PSI spikes and has bypasses as low as 50 PSI...

This is just one example of what's out there -- keep in mind that Surplus Center is essentially handling "closeouts and overstocks" and may not be representative of the overall marketplace...

http://www.donaldson.com/en/ih/support/datalibrary/000630.pdf

 

[BobRip]

I wonder if you could use the PTO return port for your supply line of the standalone system and then dump the return back to the fill cap on the tank. You would probably want to make a dust cap on the return or get a spare cap and drill a hole in it for the return. All low pressure, no danger of starting the engine and blowing the system. Easy to install and no PT modifications. No relief valve, orifice.

 

[woodlandfarms]

On my PT, there are three hoses for the PTO, as well as 3 hoses for the wheel motors.

Couldn't the third line (the over flow line?) have a small micron filter on it? Again, this is all being said from someone who has no clue so take it as a wild stab in the dark in terms of finding a low pressure but flowable place on the PT.

 

[Bob999]

I have installed a filter on the return line of my mower to provide additional filtration. It has worked well for me.

http://www.tractorbynet.com/forums/power-trac/146146-pictures.html#post1686972

 

[J_J]

On my PT, there are three hoses for the PTO, as well as 3 hoses for the wheel motors.

Couldn't the third line (the over flow line?) have a small micron filter on it? Again, this is all being said from someone who has no clue so take it as a wild stab in the dark in terms of finding a low pressure but flowable place on the PT.

Carl, the third hose on your PTO and wheel motors are for case drains for hyd motors on implement that have them. My PT has drain lines on the PTO circuit, and wheel motors. If you did put a filter on the wheel motor drain lines, it would catch anything from circulating through the closed loop circuit, and the out put from the pump case drains goes back through the radiator, and then back to tank. If you did put them on the wheel motors, you would want a low bypass pressure to insure there is not a lot of back pressure on the wheel motors, and pump.

 

[J_J]

I wonder if you could use the PTO return port for your supply line of the standalone system and then dump the return back to the fill cap on the tank. You would probably want to make a dust cap on the return or get a spare cap and drill a hole in it for the return. All low pressure, no danger of starting the engine and blowing the system. Easy to install and no PT modifications. No relief valve, orifice.

I don't know how much GPM the 1 micron filters can take, but you could split the return flow and run, say about 3 GPM through the 1 micron in a bypass configuration, and the rest of the flow through the regular circuit. Maybe something like this.

https://www.surpluscenter.com/item.asp?item=9-4078&catname=hydraulic

 

[Clarke]

I never saw that post - how well does that pump work with cold oil? The thermal protection on my used tuthill pump sometimes kicks in when the temps are below 20. This winter, it will be in a heated area (50), so it should not be an issue.

Did you ever do the quick disconnect setup? I used some 3/4 flat face fittings on mine. One could even use o-ring seal hydraulic fittings with female caps for when it is not being used.

Ken

I never run it in the winter although I don't believe there would be a problem might just slow it down a little. I still run it with the copper tubing in the tank fill one on top the other pulling from the bottom. I just hook it up and let it run for several hrs sometimes over night.

I'll try to get a better picture maybe a side view. It is a simple device. 1725 J model oil burner pump, oil burner coupling, 1/3 hp motor and the three micron hydraulic filter.

You can most likely find an old pump at the salvage yard where the heating contractors take there junk or check with an oil company.

Works good for me.

sg

 

[BobRip]

I don't know how much GPM the 1 micron filters can take, but you could split the return flow and run, say about 3 GPM through the 1 micron in a bypass configuration, and the rest of the flow through the regular circuit. Maybe something like this.

https://www.surpluscenter.com/item.asp?item=9-4078&catname=hydraulic

Thanks for the link. I was not very clear in my post. What I was thinking was you would use an electric pump to pull from the return line and dump the pump output into the 1 micron filter and then back to the tank top. This way you could filter for hours if you like. Does this make sense or have any value.

 

[jaquetarr]

Is this design heading towards a separate filtering system taking from & returning to the res tk? Or is it going towards installing a parallel filter bypass on the returns line?

I think the continuously running (key on) separate filter system would be best, easiest to install and give a greater flexibility in mounting.

The folks at AMSOIL figured out a long time ago; if you keep the dirt & water out of the oil it will last a long time. Might work for PT as well.
tks, tim

 

[BobRip]

Is this design heading towards a separate filtering system taking from & returning to the res tk? Or is it going towards installing a parallel filter bypass on the returns line?

I think the continuously running (key on) separate filter system would be best, easiest to install and give a greater flexibility in mounting.

The folks at AMSOIL figured out a long time ago; if you keep the dirt & water out of the oil it will last a long time. Might work for PT as well.
tks, tim

I like the separate filtering mechanism. Just trying to minimize changes in the PT. I don't know enough to feel comfortable doing that. I am sure that others do.

 

[jaquetarr]

If I understand a previous post from Mr JJ,
the bulk of the Hyd oil stays in the pump / motor circuit. Leak off losses are make up by the replenishing pump. (as opposed to the oil pickup from the Res tk > to the pump > to the motor > to the res tank.)

If this is correct, it seems like any filter would have to be in the main oil flow to catch dirt / wear particles. Wish PT would supply a good Hyd Diagram.
Seem like a pump or motor failure would wipe out both within a few seconds as the metal was carried back & forth.
tks,
tim