Jimna 284 hydraulic problem

[adpl]

I have just replaced the hydraulic filter housing and outletpipe (broke the housing and bent the pipe with a tree stump impact...whoops). the FEL is working (hesitant but works) but the rear power lift will not operate. The tractor is spewing quite a bit of foamed hydraulic fluid from the resivoir vent when the FEL is lowered (under the seat, has been topped off). The only thing I can think of is the the filter might be in backwards. There is no arrow to show install direction on the new housing...does the philips head screw in the housing go toward the pump or the cotter pin on the opposite side go towards the pump (I have uploaded photos, hopefully they will embed.....new to this site). Do I need to prime the pump/line? I used AW 32 fluid to replenish the resivoir....I am guessing the foam is a funtion off air escape from the system and or reacting with the old fluid. Any ideas? Any and all help will be much appreciated!!!

 

[Bob Rooks]

The cotter pin side is the inlet. That is the by-pass relief valve.
The aerated oil is a function of an air leak in the lines on the suction side of the pump. All hydraulic oils are miscible.

 

[greg_g]

And once you remedy the suction leak, recheck the sump level once the bubbles settle out. If the loader and/or rear lift is/are raised, make sure the engine is running when they're lowered. If you lower them with the engine off, the sump level will rise - possibly to the point of overflowing.

My Jinmas had only one hash mark on the hydraulic dipstick. I took that to be the full mark. I never added any fluid unless/until the stick came out dry. And when you check levels, don't screw the stick back in. Just unscrew, wipe, set in hole, remove and check. Top up if required, then screw back in when done.

//greg//

 

[Affordable]

The foam is air getting into the system,I would check all the fittings from the pump on pressure and return. The fittings on the pump have O-rings that seal them ,did you use teflon tape on the fittings when you added them to the filter head ? Also check all the hard lines for cracksThe hydraulic fill is behind the seat ,that is where you refilled it correct ?
I have had alot of customers that said the refilled the fluid only to find they filled the wrong area.

Tommy
Affordable Tractor Sales
"Your Jinma PartsSuperstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[RonMar]

Is that spin-on a filter or a mesh strainer cartridge? If it is a filter, it may be too restrictive for a suction application. IE: You cannot put a 10 micron filter on a suction side of the pump. It should be around I think a #100 mesh, which I think works out to be around 150 micron. Strainers on the suction side, filters on the return side...

 

[adpl]

Thanks for the advice, so....if the cotter pin side is the inlet, then the cotter pin side would go toward / facing the resivoir and not the pump?
I used some thread / gasket sealant I found at the auto parts store, do you think the teflon tape is better?

 

[Bob Rooks]

RonMar posted a good question. Is the filter a suction filter for the pump or a return line filter to the reservoir? If it is a return line filter then it's okay, nominal rating is 10µ (btw. it's a pleated paper media filter). But if it is a suction side filter for the pump it is the wrong filter, should be a Wix #51553 33µ or equivalent.
Don't use Teflon tape on hydraulics. Pieces of it can tear off on the inside and get stuck in your relief valve.

 

[greg_g]

do you think the teflon tape is better?

Not unless it's installed competently. Because many owners have tracked down hydraulic problems to choke points obstructed by loose pieces of improperly applied teflon tape. My general rule is that compounds are for metal threads, tape is for non-metal threads. But if you like teflon, there is a compromise; teflon compound.

//greg//

 

[biggerten]

Is that spin-on a filter or a mesh strainer cartridge? If it is a filter, it may be too restrictive for a suction application. IE: You cannot put a 10 micron filter on a suction side of the pump. It should be around I think a #100 mesh, which I think works out to be around 150 micron. Strainers on the suction side, filters on the return side...

The OP pictures a NAPA 1551, a google serach shows that to be a 10 micron filter. Furthermore, he asks which end goes towards the pump. If it's on the outlet side, it would explode. So it MUST be on the inlet/suction side.

Your point about the 150 micron is a good one. He has a 10 micron filter on the suction side. I wonder what happens. Does the pump just cavitate? Does the vacuum created overcome the seals and let in air? Does the bypass come into play?

 

[Bob Rooks]

If this filter assembly were used on the suction side of the pump it would only be marginally effective. While it has a nominal flow rate of 12 - 16 gpm, that has a lot to do with the viscosity of the oil at a given temperature. So when the oil is cool the filter by-pass will be open, rendering the filter useless.

I would use it on the return line to the reservoir from the valve block.

But if it were to be used on the pump suction then a different element must be used. However, it's your pump not mine. Your call.