Variable speed transmission

[Spiffy]

</font><font color="blue" class="small">( I don't think you can draw much fluid through the small micron filter. They usually use them in bypass circuits to aid in the filtration over time. )</font>

No, I don't think a fine filter on the suction side would be good, but for the rated GPM of a PT (20GPM combined steering and PTO ?), you wouldn't even have to run a bypass on the return side for a 1" inch fitting filter head.

This one comes with a 10 micron, but, if I remember right from looking at this a couple monthes ago, you can get replacements in 25, 10, 3 and maybe 1 micron.

I also noticed the same site had suction filters with 5psi relief; they had suction filter gauges too.

 

[Gravy]

FWIW,

Inspired by a previous thread on filtration, I've bought a 3 micron filter assembly (surpluscenter.com), hoses and quick-disconnects (TSC) to make a main PTO filtration system. The plan is to plug it in in place of the mower after a mowing session. My thinking is that any contaminants should be in suspension at that time, so I should get good filtration efficiency without having to keep an eagle eye on a restriction gauge while mowing.

I would have preferred a 1 micron setup, but those seem to be made of unobtanium, and 3 microns beats the heck out of 10.

Of course, I only have about a dozen or so other projects that I REALLY need to finish before I actually assemble and test this one, so it might be a while before I can report my findings...

I'll let you all know how it works out...someday.

Gravy /forums/images/graemlins/tongue.gif

 

[JerryG]

I don't know if you guys have seen this site or not. He has some very information on filtration as well as other things.

 

[J_J]

Why not put the high pressure filter inline [ it can not be a regular filter ] with the pump to protect it from contaminants. I would also make sure that the filter can pass the GPM's that your PT is rated, A slow down of the mower would be a good indication of the condition of the filter, If you put in on the return line, the pump is passing unfiltered oil or slightly filtered oil.

The site that Jerry G provided to is a very good site for info. I have read through it many times.

 

[KentT]

As far as an auxiliary (sp?) filter, why not just build some sort of mounting plate for a filter that you could run through the PTO connections, when you're not running something that requires the PTO...

That's an existing high volume pump on a circuit that's only used part of the time... seems it would filter and recirculate the entire PT's hydraulic tank very quickly....

 

[J_J]

True, but the point is that you would want to filter the oil before it goes through the motor. If no motor is in use you could filter or not.

 

[Spiffy]

<font color="blue"> As far as an auxiliary (sp?) filter, why not just build some sort of mounting plate for a filter that you could run through the PTO connections, when you're not running something that requires the PTO...
</font>

That would be a very simple way to fine filter the oil, but I'd still put it permanently on the return so it's always filtering - the only problem being [assuming it's the same as mine was] that the return is different line whether the PTO is in use or "idle". Now if you put in that reverse valve [another thread, BTW I'm very happy with mine /forums/images/graemlins/smile.gif ], you only use one line so a filter would always have the PTO flow.

Of course [as I think JJ pointed out] that still doesn't protect the pump or attachement motor against tank introduced contaminates - but they'd only get to make the trip once! /forums/images/graemlins/grin.gif

 

[Gravy]

My filter setup will handle the flow, but won't handle high pressure. It's a return line filter rated for about 30GPM and 120 psi max. It will simply connect to the main PTO circuit in place of the mower or other hydraulic motor.

My plan is to plug it in after a mowing session and let the engine run, filtering the hydraulic oil while I wash the dust and clippings off the machine. This should give the entire volume of the oil several passes through the filter while its hot and any contaminants are still suspended.

Ideally, I'd like to ultra-filter all of the oil all of the time, but I think what I've got will clean the oil a whole lot better than the factory setup for a small fraction of the cost and effort of the ideal fulltime ultra filtration design.

One Of These Days, Real Soon Now, I'll actually assemble the parts that are sitting on a shelf, and try it out. I'll post photos shortly thereafter. Maybe even tomorrow. It COULD happen... /forums/images/graemlins/crazy.gif

Gravy

 

[BobRip]

Are you planning to keep the engine at idle to reduce the pressure, or will it be OK will full flow and the pressure will be low since there is plenty of flow capacity and no back pressure?

Bob Rip

 

[Gravy]

IIRC, it's rated for 30GPM. It *should* be able to handle full flow with no problem. Nonetheless, I plan to start out at idle with hot fluid, and watch the pressure gauge very carefully. The internal relief valve is set at about 25psi, so it should bypass well before anything blows out.

I'm going to try to put it together and run it today, so I may be able to report results this evening.

Gravy