Hydraulic Oil Filter Failure

[1Marshal]

Hello to all users. I am new with a specific problem. I have a log splitter custom build approx. 8 yrs. ago. Since new, I discovered a small annoying leak either in the filter gasket or the adjoining pipe thread coupling. It became worse over the years where the filter bracket could be easily turned in place. I assumed the pipe thread coupler attached to the "in" or "out" sides were leaking. I decided to fix the problem with new pipe thread compound, after cleaning the fittings, and replaced the existing filter with a matching filter from a major auto parts provider. The replacement filter gasket started leaking within the first 4 hours and subsequently totally failed. The gasket exited the housing at one location. I replaced the filter and gasket with a new unit based on gasket failure. I turned the new filter 1/2 turn past contact point and tried the system. It worked for approx. 1 hour under useful stress and it to failed. The bulge of the gasket was greater and fluid loss substantial. Note that I lubricrated the two gaskets with oil before placing them in the slot for the gasket. One thing that did concern me was the unaccounted for enlargement of each gasket as it was pushed into its housing slot. Without stretching it, it became longer than the space to install it. With a little coaking each time, it self fitted and a thumb riding around the rim indicated it was properly seated and not protruding at any point. What is causing the gaskets to fail?

 

[Coyote machine]

Over-pressure condition? Show pics of setup and damaged items.

Welcome to TBN. You might get more responses if you post this thread in another forum, other than new member introductions. Here one introduces oneself to the TBN members.

 

[1Marshal]

Confused because nothing changed except the filter/gasket. Original came from Northern Tool and the later from NAPA Auto Parts. They look and attach the same.

 

[oldnslo]

Like Coyote machine stated, sounds like an over pressure condition. Just because the filters look the same don't mean they are. Most spin-on filters are only good for 60 - 80 PSI with 100 PSI being max pressure. If this is installed in the return line I would suspect the filter is sized to small or there is a restriction in the outlet of the filter.

 

[murphy1244]

Repost this in the Hydraulic forum so JJ can see it. He will help you. Oh Yea, Welcome

 

[crackerjack222]

Any chance the filter base is warped?

 

[Coyote machine]

Confused because nothing changed except the filter/gasket. Original came from Northern Tool and the later from NAPA Auto Parts. They look and attach the same.

"nothing changed except the filter/gasket." That is a change. Hydraulic filters are NOT the same as oil filters. Hydraulic filters are designed to handle way more pressure than an oil filter. As stated, looks don't mean anything when it comes to filters.

 

[1Marshal]

Thanks for the message reply. I think you are onto something. The size of the filter may match, but your point about internal makeup makes enough sense that its worthy of going back to the original filter. I will let you know what I find with this approach. Thanks for your help.

 

[1Marshal]

Thank you for the technical info. I assume that GPM also means higher pressures due to volume requirements of the pump. Any way of knowing how many psi is needed for 28 gpm?

 

[Briana03]

Welcome to TractorByNet!

I moved your thread to the Hydraulics forum.

 

[IceStationZebra]

Not to mention that a change in the filtration rating could have a significant affect on the back pressure. My wild guess is that the original was around 40 micron, and it would be easy to interchange with an equally sized filter anywhere down to 3 micron.

Brian

 

[mrmikey]

Any way of knowing how many psi is needed for 28 gpm?

Not to sound like a smarta$$ but that isn't a valid question.
Think of it this way, a pump creates flow i.e. gpm, flow restriction (either thru a motor or cylinder for example), creates pressure i.e. psi. You could have an 1 1/2" garden hose delivering 28 gpm at 100 psi , you could also have a 1" hose delivering the same gpm at 300 psi.

On your problem, any chance the filter head is on backwards or the bypass valve inside is messed up....Mike

 

[J_J]

GPM's is dictated by the displacement of the pump and the rpm.

The pressure rating of the pump is designed into the parts as far as type of metal, thickness of the metal, etc.

Pressure is developed by the hyd component using the fluid, otherwise the resistance to the flow.

I assume you are talking about a two stage pump, which is pumping 28 GPM's at a low pressure.

The pump is only pumping about 7 GPM's at 3000 psi, and 28 GPM's at around 700 psi.

The pump will try and pump a higher pressure, but a relief valve is incorporated into the valve to relieve the pressure at a safe pressure to protect the pump.

 

[1Marshal]

Thanks for the detailed info. I can't know the spec's of the two filters other than to say the replacement filters probably was a less micron and it created the PSI to find the weakest point which was the o ring. I have purchased a new filter with the proper GPM and will see if the problem is corrected by the change. I guess it will be difference. Thanks to all that responded. I'm better in formed now.

 

[1Marshal]

Thanks JJ. I acknowledge your informed reply. It's still confusing to me, but I accept what I didn't know. Thank You---yes the pump is a two stage pump---I just did not know the "stats" you provided were happening.

 

[Dirthog]

Marshal two different things pressure equals force while GPM equals speed.

 

[Coyote machine]

Have you changed to the new filter and what are the results?

 

[J_J]

Your filter needs to be able to handle 25 GPM at maybe 50 psi.

Microns is the filtration and the size pf the filter and the port size will dictate the flow capability.

There is usually a bypass in the filter head and it has a rating.

This filter is a 10 micron return filter and is just for reference. It is a 7 GPM filter with a max pressure of 200 psi.

The fluid will start to bypass at 18 psi.

Surplus Center - 3/8" NPT 7 GPM RETURN LINE FILTER

This is a 70 10 micron return filter, 200 psi rating and will bypass at 25 psi. 1 1/4 in ports

Surplus Center - 1-1/4" NPT 70 GPM ZINGA RETURN FILTER

You need a filter with a capacity greater than 28 GPM.

 

[1Marshal]

I do not think that is possible as the filter change caused all the problems. I didn't ask for any specific micron values or matching GPM to ensure they were exact. I trusted the cross reference but apparently it was different. I haven't installed the new proper filter, so at this point, I can hope the new filter will correct my problem. I will post a reply later. Thanks for your time, thoughts and views.

Not to sound like a smarta$$ but that isn't a valid question.
Think of it this way, a pump creates flow i.e. gpm, flow restriction (either thru a motor or cylinder for example), creates pressure i.e. psi. You could have an 1 1/2" garden hose delivering 28 gpm at 100 psi , you could also have a 1" hose delivering the same gpm at 300 psi.

On your problem, any chance the filter head is on backwards or the bypass valve inside is messed up....Mike

 

[Kaliburz]

Confused because nothing changed except the filter/gasket. Original came from Northern Tool and the later from NAPA Auto Parts. They look and attach the same.

If you have your original filter still or it's number, reverify on the NAPA site that that is the correct one. Or go over to the WIX filter site and see if it has a cross over and see the specs. If you have the owners manual, take a look at what the part number is or if it lists the spec in the descriptions.

Most dedicated hydraulic filter bases (ie the mount) have a built in bypass spring. When the filter gets full or an over pressure happens, the spring opens so not to blow the gasket/filter. Maybe the spring is stuck..... Since you said that the original lasted for a while, it sounds like the by pass may not be opening. I highly doubt that the filter has a built in bypass.....but.....

In order to check the by pass, you'll have to remove the two hoses and look down into the hole. One side will have a spring (well, should). That spring is what keeps it closed sending fluid to the filter. The other side is the inlet. If you feel bold, take some thing and see how much force it takes to open up the bypass. If you can open it w/ your hand pressure, then it is A- working B- set low (so it shouldn't cause an over pressure in the filter). If you CAN'T push it open, it is stuck closed....there is your issue. Filter is getting over pressurized from the cycling.

Also, check your tank vent/breather is clean. This is the return side filter, so if the oil tank is getting pressurized, no relief valve will save your filter. Or remove the cap when running....to test if the cap/vent is working. Oil gets warm when it runs, so it expends. (some may not agree with this....)

Hope this helps....

Edit:

On the Northern Too site

Northern Filter number...........WIX number.......GPM.........Burst PSI
778648.......................51551............12-16.........440
778650.................................none