Inline Hydraulic Spin On Filter

[HomesteadOC]

Double check your valve spool. Normally; the PB port would be plugged, if no further valves down stream as the PB is the same pressure as the Power (P) port. There should be a port labeled T for Tank or R for return. Is this an existing installation or something you are building? If the spool valve is new it should have come with the technical details sheet. But then, I have been fooled before on this stuff.

Pictures always help us do this armchair trouble shooting. Info on the spool valves would be helpful also, there are resources for checking these out such as the Tech desk at Surplus Center, a TBN advertiser.

Ron

The hose on the top marked PB goes to the port marked PB on the 2 spool loader valve, the hose on the bottom marked M goes to the main input to the 2 spool loader valve marked M I believe. Id like to mount the filter housing horizontally in that fender cross bar in the top of the picture and do a short hose or some hard pipe into that manifold. Ill post pictures of the 2 spool valve when I get home tonight.
Other than these hoses the only other hydraulics is the 3PH, but thats it, so its not complicated. Maybe mine is plumbed funky from the 70s, but Im pretty sure it works correctly. I can only trust the seller as I bought it non-running, but that should be remedied as soon as I get a new oil ring delivered. If you want a full documentation of my journey heres a link.
http://www.tractorbynet.com/forums/mitsubishi-satoh/392553-77-satoh-beaver-s370d-wont.html

 

[HomesteadOC]

I'm pretty sure he's considering a 3 spool with grapple by his posts else were.

Yes Id like the 3 spool with joystick and grapple, but the valve is probably way oversized for my pump. The valve I was considering is 25gpm and my pump does around 4gpm. Im worried if I use the joystick to operate boom lift and bucket curl at the same time its going to move extremely slow. The grapple lever would be used for a 3PH hydraulic top link that is not yet added. I like the idea of a joystick, but might try a cheaper 3 spool valve with individual levers that is matched to my pump. Either way I really want the filter. My hydraulic screen was shredded and I pulled a bunch of metal shavings out of the transaxle/reservoir with a magnet tool. Ive since rebuilt the strainer, and milled recesses in all my drain plugs and pressed in rare earth magnets. I did the front axle last week, the 2 rear transaxle plugs yesterday and the oil pan plug today. I ordered that filter and housing I mentioned earlier and it will hopefully arrive tomorrow or tuesday. I want the filter in place before I start cycling hydraulics.
FYI My tractors pump according to tractor data is 3.84gpm flow 1920psi pressure. The filter housing has a bypass spring set at 25psi so it should definitely not be under full pressure of the pump.

 

[HomesteadOC]

The big hose on the left marked IN is the hose marked M for main on the previous posts picture. The hose marked PB is seen on the top of the picture with a 90 coming out of the valve.

Close up of the PB hose and the 90.

I got the filter and housing today, and they fit each other. My hose ends measure 1/2 ID and look like theyre NPT, so the 3/4 NPT isnt convenient. Also the filter and housing are bigger than I though so its not going to fit in the area under the seat next to the fender and manifold. The filter housing has a bypass and Im worried that the pressure will overcome the bypass quickly. I looked at the prince brand on amazon and they dont have one of these that come in 1/2 NPT. I do like the filter though as its cheap and Wix seems like a good brand for hydraulic filters. Im now planning on mounting it under the plate that the valve sits on top of and making a hard pipe 180 degree turn to go into the housing.

Do I need a bypass in the hydraulic systems filter housing? What is the danger of no bypass and how would I know if the filter is in bypass? Do I need the large port size to get a housing that will fit this cheaper filter?

 

[LD1]

Without being there to actually trace lines out.....I worry that the loader PB that you think simply runs back to "tank".....is actually feeding the 3PH.

Dont know on that tractor with aftermarket loader.....but that is how modern stuff is. Loader valve PB feeds the 3PH. But usually accompanied by a dedicated tank line coming off the loader valve. IE: 7 hoses on the loader valve instead of 6.

IF that PB line you want to put the filter on is indeed being used for the 3PH.....you will blow apart a return filter/head the first time you put something heavy on the 3PH.

 

[HomesteadOC]

Its not hard to trace the lines, the high pressure in comes from a small circular manifold to the loader valve and the PB from the valve runs back to that same circular manifold. I think youre right about the 3PH, a friend of mine was saying it would be a safe bet to put it on the suction line from the pump, but its a hard line so Im not sure what to do about that. Im afraid to cut and splice in the filter in the hard line and dont really want that line to be a flex hose since It hugs the tractor so well.
My plan now is to get the tractor running and cycle all the hydraulics a few times to get the new fluid to flush everything back to the tank and through the strainer and around all the magnet drain plugs to clean it up and then drain and refill after a few hours of tractor play time. Ill save the inline filter mod for when the hard line breaks or I can afford to take it to a hydraulic shop to do the splicing.

 

[swnoel]

http://www.baumhydraulics.com/files/infobuild/terms_hydraulic_control_valve.pdf

 

[swnoel]

I'm curious whether you have 6 or 7 lines from that valve. PB is a high pressure line designed to power something else. If you only have 6 it probably is just a low pressure return .

 

[Tractor Seabee]

I'm curious whether you have 6 or 7 lines from that valve. PB is a high pressure line designed to power something else. If you only have 6 it probably is just a low pressure return .

OP, think this through; if you do not have 7 lines from the valve, you do not have a PB outlet that is used downstream. Otherwise one of the 6 lines we can see has to be the return to Tank (low pressure where you want a filter to be) and the 3 Point is first in the flow. I am curious; why the filter? There is a pump suction strainer and possibly a suction filter in your system. They will protect your pump adequately; you are just adding a restriction to flow back to the Tank which may raise that pressure. Do you have a shop manual for your tractor or a spec sheet for the valve? Info you need will be in those documents. Every manufacturer does things different and you never know what the last owner and/or their mechanic did either.

Ain't this arm chair trouble shooting fun!

Ron

 

[HomesteadOC]

I want the spin on oil filter for a finer filtration that the strainer allows. The hydraulic system is filled with gunk and strainer parts from the last owner not changing the fluid and the strainer screen being sucked through the “basket” or “frame” of the strainer. Im sure these pieces are everywhere and I just want to have them cleaned up and prevent something like that from happening again. When I had the strainer out while I was rebuilding it I swiped my magnet tool around in there just to see what I could get and I got globs of stuff for 10 or so passes.

There is only the suction strainer and no suction filter, I have a shop manual, but I havent found anything in there about how the hydraulics work yet. Obviously the manufacturer didnt think it needed an inline filter or they wouldve added one, but most new tractors have them I believe, so I want one too. Anyway, right now Im going to just run the tractor for a few hours cycling the hydraulics as much as possible and do a drain and refill. I did the same on the front axle and got some extra clumps to come out. Ill probably do another drain and fill after 50-100h depending on how things go.