Splitter troubles

[trafick]

Hey All,

A few years back I purchased a Northstar 31ton splitter from Northern. The one with the infamous hose problem. (the hose keeps breaking at the fitting) Well the hose sprung a leak for the umpteenth time the other day and I finally decided enough was enough. I drained the oil and replaced the hose.

While I had the oil drained I decided to go ahead and change the filter. I couldn't find the replacement at Northern so I went to my local hydraulics dealer instead. I showed him the old filter and he gave me one he said was a replacement for it. I went home, put everything together, filled with oil and started splitting.

About an hour later my wife started screaming, "IT'S GUSHING, IT'S GUSHING" Sure enough I look where the oil filter used to be and hydraulic oil is gushing out. I quickly shut down the engine, grabbed a couple of buckets and kept what oil I could from draining on to the grass. When the oil stopped I looked and the center piece of the flange the oil filter was screwed to exploded and the oil filter was on the ground with the center piece still attached.

Needless to say I now have to buy the flange ($45) and 5 gal of hydraulic oil ($40) on top of what I already paid for the hose ($19) and the new filter ($14). All to fix a hose leak.

My question is this, What caused the flange to fail? The new flange comes with an oil filter that is the same size as the original so if it was the filter, the new one should work. I'm also thinking about putting a ball valve inline with the filter so if this happens again I have a quick shutoff. Any thoughts?

 

[savageactor7]

I dunno but it sounds like a bad filter to me. Under load I guess the filter is the weakest link psi-wise. Maybe there an 800# you can get on line to get the right filter for that Northstar. Someone here will probably tell you how to knock the pressure too if it continues to happen.

 

[jdemaris]

When the oil stopped I looked and the center piece of the flange the oil filter was screwed to exploded and the oil filter was on the ground with the center piece still attached.

Needless to say I now have to buy the flange ($45) and 5 gal of hydraulic oil ($40) on top of what I already paid for the hose ($19) and the new filter ($14). All to fix a hose leak.

My question is this, What caused the flange to fail?

I don't know exactly how all is hooked your splitter, but it must follow some sort of standard convention. Most "throw-away" oil filters on rigs like yours are on the hydraulic return circuit with there is usually little to no pressure. The only thing that can create high pressure there is either oil that is too thick - or the wrong micron filter. Sounds to me that someone sold you the wrong filter, i.e. they sold you one that will physically fit but has too fine a micron rating. When oil can't pass - it either has to break something - or with some good filter-housing assemblies - there is a bypass valve. This sort of problem is not uncommon and happens a lot with farm tractors, bull dozers, etc. - mostly from starting in cold weather when the oil is too thick. But, your filter housing sounds like a real cheap unit.
A filter housing with 3/4" pipe needs a 10 micron filter to pass 20 gallons of oil per minute as long as the oil is not too thick. Housing with 1 1/4" pipe with a 10 micron filter is rated at 35 GPM. If you put the wrong filter on either, you've got problems. You can buy an entire new filter housing with cold bypass and new cartridge rated 20 GPM for $14. The bigger 35 GPM assembly costs $30.

 

[trafick]

I was able to get a 15 gpm, 15 psi bypass with a 10 micron filter at Northern for $45. I guess I got ripped but I need this thing yesterday. BTW My pump is rated at 11 gpm so I should be OK.

jdemaris you are correct, the filter is on the return side. Where are the $14 ones? The ones I saw were $14 just for the element. Thanks for the info.

 

[kevin j]

31 tons means probably a fairly large pump and cylinder, thus higher flows.

If it has the small 1 inch threaded center post filter (about 3.8 inches diameter, similar to a full sized car oil filter) then I suspect it is too small. May have been stock on the machine for cheap price, but just sized too small. I would upgrade to the bigger filter, about 5 inches diameter and 8 inches long, with 1-1/2 inch threaded center post. Those can be under $35 at Northern or Surplus center. Make sure there is a bypass in the head, usually 25 to 40 psi differential.

Although there is minimal actual static pressure in the return line, the pressure required to move oil flow through can be high. This can happen several ways.

-When retracting, return flow out of the closed side of the cylinder is greater than pump flow, by the area ratios. Typically 20-40% more flow than pump is putting into the rod side.

-Upon startup with a new or empty cylinder, trapped air can cause flow surges in the return line if it is compressed by extending the cylinder, then suddenly expanded when the valve is moved to retract the cylinder. Solution there is to cycle a new cylinder back and forth with no load, not reaching end of stroke, so the air purges out at very low pressures.

-If there is water in the oil, the water can cause paper (cellulose) elements to swell and restrict flow. Normally, the bypass valve should open, but see the next point.

-Another possibility I have seen twice (once on a new machine, once on a rental unit) is that the filter head could be installed backwards, i.e. in & out turned around. Elements are designed to flow from outside to inside, and the filter head is designed for the bypass valve to work in one direction. If flow goes through the element inside to outside, the pleats will not support properly. They will collapse outward, further restricting flow, especially if the paper is swelled up by absorbed water. Then, since the flow through the head is the wrong direction, the bypass valve does not work. Pressure drop builds up until the flow moves through the plugged element, the hose blows, the filter can or head blows, or (most likely) the gasket between filter and head blows.

Solutions:
-Use a larger filter
-Use microglass or synthetic elements, not paper/cellulose.
-Make sure the flow is correct direction
-Check the bypass valve direction and operation.


kcj

 

[jdemaris]

I was able to get a 15 gpm, 15 psi bypass with a 10 micron filter at Northern for $45. I guess I got ripped but I need this thing yesterday. BTW My pump is rated at 11 gpm so I should be OK.

jdemaris you are correct, the filter is on the return side. Where are the $14 ones? The ones I saw were $14 just for the element. Thanks for the info.

I have no idea how you got charged that price. Northern list the assemblies right how for $13.99 (filter and housing assembly) and Burden (Surplus sales) gets $14.99. The filter alone almost costs the same.

Your splitter has an 11 gallon per minute pump when running in the high stage. The 10 micron filter it came with it is rated at 11-15 gallons per minute with the correct oil. If the oil is NOT winter-grade, and it's cold out, that filter will barely pass 10 gallons per mintue until the oil warms up. And, if somebody sold you a finer filter, it will pass even less oil and could blow up once the cold oil flow exceeds what the bypass can let through. Standard filter configuration of this use is a spin-on filter 1 1/2" X 16 threads and a can that measures 6.8 " long by 5" diameter. If you were to go to, let's say a NAPA store to match it by size - they can sell you a #1632 that is 7 micron, # 1746 at 5 micron, #1759 at 10 microns, or an # 1865 that is 25 microns. They all look the same and that's the many of filters made for hydraulic return systems. There are many more that will fit and look the same that flow much less and are made for engine oil, fuel, etc.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_12006_12006

http://www.surpluscenter.com/item.asp?UID=2009022516124737&item=9-7504&catnam;e=hydraulic

 

[trafick]

Well I did what I should have done in the first place and looked at the manual. Indeed the part # was the one jdemaris is talking about so I took the expensive one back and got the cheaper one. I also cleaned the suction strainer and changed the hydraulic fluid. Now we'll see how long this all lasts but at least I have a ball valve in line so if it goes BOOM again I can shut off the flow of oil.

Thanks all for the replies.

 

[Jags]

.....but at least I have a ball valve in line so if it goes BOOM again I can shut off the flow of oil.

If I am picturing this correctly....if you shut off that ball valve (I am assuming on the return line), your gonna watch other things go BOOM if that engine is still running.

 

[trafick]

Jags,

The ball valve is to stop the oil from draining from the tank should the filter explode again. But you are correct, other things will go BOOM if the valve is closed while the splitter is in operation.

 

[Jags]

Jags,

The ball valve is to stop the oil from draining from the tank should the filter explode again. But you are correct, other things will go BOOM if the valve is closed while the splitter is in operation.

Aaah, positioned between the tank and filter. Got ya. Just make sure you get that engine shut down in a hurry. You don't want to run the pump dry.

 

[kevin j]

you could put a check valve instead of ball valve. Free flow to the tank, no reverse flow. Need an oversized one to keep the pressure drop down.
I would be worried about it being inadvertently closed, by vibration, by a piece of falling wood, by inquisitive finger when the splitter is parked or stored, etc.

kcj

 

[brad068]

You could take the handle off the ball valve to tamper proof it or just use a vacuum cleaner next time you change the filter. Stick the vacuum suction hose over the oil tank fill hole to create a negative pressure in the tank which will hold the oil in the tank while you remove the filter.

 

[kevin j]

or relocate the filter to be mounted above the water line.

 

[johnsopi]

I think that there more risk by adding a valve, that it will be inadvertently closed, then the filter failing again. Keep it simple soldier

 

[Jags]

I think that there more risk by adding a valve, that it will be inadvertently closed, then the filter failing again. Keep it simple soldier

I agree completely. The likely hood of another filter failure is pretty small.

 

[trafick]

I hear you guy's but it's in and the tank is full of oil. I'm the ONLY one who uses this thing so as long as I remember to check it before every use, like when I grease, I should be OK.

I can now change the filter without draining the tank and can work on the return line. The valve is pretty tight so I don't think it will close during use and the thought of all that oil gushing out with no way of shutting it off...