adding hydraulic filter on backhoe

Michael Price · Jul 2, 2012

I put a hydraulic filter on a 3pt backhoe and it blew the filter off. It runs off the tractor hydraulics. The filter is on the return side going into the tractor. Since the filter isnt on the pressure side it must just be to much pressure because of the smaller hose. Im wondering if I plumb in the return side with a bigger tube, like a one inch instead of the 1/2in if that would lower the pressure on the return side and keep from blowing the filter off?

Anonymous-0 · Jul 2, 2012

The return line for the backhoe is just using aux. hydraulics and has a lot more pressure than the main return line on the tractor. If it uses a braided hyd. hose it would be for higher pressure.

greygoat · Jul 2, 2012

I built a woodsplitter with a 5 inch bore
cylinder..It has a 3-1/2 inch diameter piston rod
It take 2-1/2 gallons of oil to extend 30 inch"s.
Because the rod is so large it takes only about a gallon to retract it.. this means that the oil
behind the piston is being pushed out at a tremendous velocity. With a 7 gallon per minute
pump, return oil may be going out a 20 GPM. (I"m
not going to do the Math here)I plumbed the
system with 3/4, 2 wire hose, the return line
with 1 inch hose, and used a return line filter
with 1-1/4 ports,rated at 30 GPM. My directional
valve make was "Brand-Omaha", 1 inch ports, rated
40 GPM. No problems.Return velocity can blow
filter elements off!

souNdguy · Jul 2, 2012

is it a power beyond setup.. or is there hyds downstream of the hyds filter?

Michael Price · Jul 2, 2012

Nope, after the filter it goes back into the tractor reservoir.

mkirsch · Jul 2, 2012

The filter you used wasn't rated for the flow. Too restrictive, which caused the pressure to build up and then... POP! Off she came.

Like trying to squeeze 10lbs of sugar into a 5lb bag...

If the tractor already has a filter, then don't worry about it.

If you really feel the need for a filter you need one that is a "bypass" style that only filters part of the oil that comes through, or one rated for much higher flow.

souNdguy · Jul 2, 2012

at that point I'd look at the fitler / head design and see what it was rated to flow. sounds like it is causing a restriction in the return path, thus raising pressure as it is not allowing a good exhaust flow as needed.

jm. · Jul 2, 2012

All the 3 point add on with tractor pto pumps, backhoes that I ever sold had a return filter. That being said they were in like a one inch or larger line. If your return is truly OPEN to the tank with no restriction the problem was with the rated flow of the filter. Can I ask what brand of backhoe. Just can,t think of one being built without a return filter. I can tel you sthin a cheap way is the alumuin filter base that tractor supply sells for using on disel fuel tanks. That filter base and filter is for flow and has large opening like 1 inch. I know a couple of guys that have used that on homemade log splitters and it worked fine.

Michael Price · Jul 2, 2012

The filter was designed for I think 1in pipe and I necked it down to 1/2 hydraulic hose. Im wondering if that the problem.

Anonymous-0 · Jul 2, 2012

Have you checked to see if the filter is plumbed backwards? Most filter heads have a direction arrow cast into the filter head.

souNdguy · Jul 2, 2012

reduction of flow = increase of backpressure....

mkirsch · Jul 2, 2012

(quoted from post at 08:49:57 07/02/12) The filter was designed for I think 1in pipe and I necked it down to 1/2 hydraulic hose. Im wondering if that the problem.

That's not the problem.

greygoat · Jul 3, 2012

Most filters designed for hydraulics have a
bypass check valve. If the filter is starting to get full of dirt, or there is too much flow, the
check valve will open to send some flow, bypass,
straight to the tank, thus preventing element
"Blowoff".(The bypass flow would not get filtered). A fuel tank filter may indeed have
larger port, and accomidate more flow, but they
usually don't have bypass check valve.If your filter head has one, thats
another indication that there's too much flow
for it too handle.

Matt in the Thumb · Jul 10, 2012

I was wondering if this is the same Michael Price from Michigan with the Smalley disk. Please let me know if it is!

Michael Price · Jul 10, 2012

yep, thats me

Matt in the Thumb · Jul 10, 2012

Well, I just picked up an old disk, appears to be a Smalley. Yours is the only other one I've found online. Read one of your old posts about it needing wheel bearings. Did you ever fix your hubs? Mine are pretty wallowed out, and the axle bolts are worn nearly through. I don't have spoke wheels. Mine has hubs and stamped steel rims. My scraper mounts are different as well. Also, I'm a Michigan guy as well!

Michael Price · Jul 10, 2012

I wonder if smalley was a michigan company, I have a 3pt cultivator from a company thats was about 10 miles from here.

Are your wheels like mine with a big bolt as the spindle and channel iron on each side of the wheel?

Mine were junk, I had to rebuild everything, the bearings were a fortune. Looking back though I probably could have used a different bearing and saved a lot of money. If you need some help send me an email. We'll get it fixed.

Matt in the Thumb · Jul 11, 2012

Email sent!

adding hydraulic filter on backhoe

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