WD45 oil flow

[TommyB1974]

My dad did an oil change on his wd45. he noticed the filter mount was loose, so he tightened it up and asked me to order a new gasket. The gasket came in and when i went to replace it, there was no oil in the filter. it was clean and had not seen a drop of oil. I blew out all the orfices, made sure there wasnt a blockage, and put it back together. (my dad used the tractor for about an hour after changing the oil, so no oil in the filter is a concern). after firing it up, oil pressure was in the normal range. however, when i pulled the filter, ther was still no oil in the filter after running it for about 5 minutes. What the hell is going on here? has anyone else seen this?

 

[Jim.ME]

The oil filter is a bypass filter with no drain back valve oil from the filter goes directly back to the crankcase. The filter only receives about 1/6th of the pump output. It should have a small oil line supplying oil into the filter. With it running crack the line and see if there is oil being pumped through it to the filter. Inside the housing with the filter off there is supposed to be a small standpipe that has a small hole or two in it to restrict the amount of oil that can go through the filter, the filter slides down over. That standpipe puts the oil up into the filter where it runs down through the filter media into the filter base and back to the crankcase. Make sure the tube is there and the holes, near the top, are open in it. If the holes are plugged it cannot let oil into the filter. It is not unheard of for that standpipe/tube to come loose and be removed with the filter, not noticed, and thrown away with the filter during an oil change. That will almost always show low to no oil pressure when that happens.

The oil pressure gauge line should be Tee'd into the same pumped oil source as the filter. Does it have oil pressure?

 

[TommyB1974]

the stand pipe is there and clear.

 

[Jim.ME]

Does it have oil pressure?

To be clear. Did you check the standpoint by cranking or starting the engine to confirm oil through the standpipe?

What oil filter are you using?

 

[TommyB1974]

I’m not sure what filter was on there. It was what ever my dad got from Napa. Yes I blew air through the stand pipe.

 

[TommyB1974]

And yes, when running the oil pressure gauge moves to normal. Just past dead center on the gauge.

 

[Jim.ME]

The NAPA filter for that tractor should be a 7011. (WIX 57011, Fram C159, Baldwin T300-M are others commonly used.)

Are you 100% sure the filter had not seen a drop of oil? Being a bypass filter with the open end down they will completely drain out as they set.

To see if the filter is getting oil, have you cracked the line putting oil into the filter when the engine is running, as I suggested above?

With the gauge showing oil pressure, I find it hard to believe the filter is not getting oil, unless that line to it is plugged. Check the line as I suggested.

 

[DrAllis]

Start the engine with the filter removed and see if oil comes up and out of the end of the standpipe. If not, there is a blockage somewhere in the filters aluminum base.

 

[kencombs]

I'm not familiar with that specific engine oil flow, but a lot, maybe most or all, bypass type systems have some way to restrict the bypass.

No oil is sent to th filter until the pressure is enough to overcome the restriction. The one I'm most familiar with is the old Chrysler flatheads. They use a shuttle valve to direct the oil to the filter, only when the main oil gallery pressure is adequate to supply bearing and the filter. Chevy in those years used a restriction without a valve. I'd hazard a guess that yours may get oil only when the oil pressure relief valve opens.

 

[Jim.ME]

I'm not familiar with that specific engine oil flow, but a lot, maybe most or all, bypass type systems have some way to restrict the bypass.

No oil is sent to th filter until the pressure is enough to overcome the restriction. The one I'm most familiar with is the old Chrysler flatheads. They use a shuttle valve to direct the oil to the filter, only when the main oil gallery pressure is adequate to supply bearing and the filter. Chevy in those years used a restriction without a valve. I'd hazard a guess that yours may get oil only when the oil pressure relief valve opens.

The restriction is the tube inside the filter that I mentioned.

 

[Jim.ME]

And yes, when running the oil pressure gauge moves to normal. Just past dead center on the gauge.

Have you done any more on this? What was the result of starting it with the filter off so you could see if oil comes out the tube?

 

[kencombs]

The restriction is the tube inside the filter that I mentioned.

My question really is" where is the other end of the standpipe passage: upstream or downstream of the oil pressure relief valve? And, if downstream is the relief valve ever open? stuck or just oil pressure just to low at the RPM being used to open it?

 

[Jim.ME]

The oil filter standpipe is fed via a tube tapped into the main oil passage from the pump. Another tube off that tee takes oil to the rocker shaft and governor. The relief valve is downstream of the tap point. The oil pressure gauge is tapped into the filter housing base. The size of the hole in the standpipe controls the amount of oil the filter receives.

Related to this is and issue with WIX/NAPA filters for these engines that surfaces at times. The WIX/NAPA filter issue is old, like back around 2010, I think. WIX issued a new filter number when they corrected the problem. The current/correct filter number is WIX 57011 or NAPA 7011. The old WIX number was 51101 (NAPA 1101). The original 51101 used a packed media for filtering. Wix changed it to pleated "paper" and there was a significant oil pressure drop noted in the ACs that used that filter, enough that the complaints lead to WIX discontinuing the 51101 and replacing it with the 57011 having a redesigned filter media which appears to be a type of material filling the housing similar to the previous packed media, which gives more backpressure than pleated paper, along with the regulating tube orifice, to maintain proper oil system flow and pressure. Wix may have bought a few engines due to that filter change.

The oil pressure drop, with the pleated "paper", occurred even with the proper oil flow regulating tube (standpipe) in place in the filter housing. I saw this happen firsthand on my ACs, so the tube alone is not the entire story on keeping the oil pressure up, the oil pressure ran lower with the pleated paper media used in those redesigned WIX 51101 filters, all of which had the tube in place. And it will run even lower if the regulating tube is not in place, regardless of the filter media, I have seen that scenario firsthand as well.