Hydraulic Oil Filter Failure

[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