I recently rewired my '49 6 cylinder and while all other gauges work, the oil pressure one does not (nor did it before the rewire). I have a new oil pressure sender on order but was working on the truck today when oil began a pretty heavy flow out the top of the canister around the rim while at idle. After shutting the engine off, I opened the canister 5 minutes later and it remained under a little pressure, spilling more oil as I removed the canister cap. After removing the filter, the canister remained about 50% full of oil which I presume is not typical. The filter was installed as part of a full tuneup by a local shop about 1 year ago just after I bought the truck. To date I have had no previous issues. The top gasket looked to be seated pretty well into the rim of the cap. I have checked the oil dipstick both before and after this event and it remains in the safe operating range.
Any thoughts if the oil pressure switch/gauge issue is connected to this overflow? Is the lack of draining an issue to address as well? I have a shop manual but didn't see this issue addressed.

 

Have you used a mechanical gauge known to be accurate to check oil pressure?

Usually the problem with canisters is that there are two gaskets on the lid, the old one may have not been removed.

Draining halfway is about right. Drain is by gravity and the drain hole is about halfway up the center tube on most of them.

 

I tried a multi meter on the oil pressure gauge per the shop manual, but couldn't get any reading. Not sure if I had the settings right either. Now waiting on a new oil pressure switch to see if that is the issue. However, before rewiring, the pressure gauge was not operational but nor did I have oil flowing out of the canister.
I also double checked the lid gasket per your recommendation but there was only 1.

 

The oil flow into the canister is restricted by an orifice in the angled base. Even with a leak it wouldn't greatly affect oil pressure. It is a partial flow or bypass filter, not a full-flow like modern cars.

Not sure where you'd use a multimeter to test the gauge. You can use a "C"-cell battery, see page 278 where it says to adjust voltage to 1.5 volts. A battery is much easier.

 

I have had that issue with the oil filter canister gushing out oil. I just did not have the gasket seated properly

Ed

 

I had the same problem with the leaky canister. I starting torquing the canister bolt to around 10-15 lbs I think. Make sure you have a gasket under the bolt also.

 

Ross is right. There are small holes running down the shaft inside the oil filter. the problem is that if sludge has built up inside those holes can get plugged. And if the truck has sat for a while you may get rust accumulation too. The problem with this filter is that it never fully drains. Some of these older canister type filters have a drain plug near the bottom. But I have never seen them on a Ford. You could weld one in though.

In addition the elbow fitting outside the filter also has a metering orifice built into it. Make sure that someone has not substituted a different fitting.

 

On the 226, the orifice is integral to the adapter on the side of the engine




Photo courtesy of Brain75