BC847
New member
To be clear, the oil filter's internal anti-drainback valve was the culprit of the oil pressure mess.
As I'm sure you know, the oil filter bypass valve is for those instances where one's oil filter is stupid plugged and threatens low pressure/flow to the bearings. It bypasses oil around the filter so as to maintain a minimum pressure/flow, albeit soiled oil.
My heap's stock/OEM cooler-cover has the oil filter bypass mounted in the passage that conveys oil from the cooler to the filter. This remote oil filter cooler-cover does NOT have the oil filter bypass. In the Cummins factory installs, the oil filter bypass is expected to be found in the remote filter-head.
The issue I've created conflicted with the design of the oil filter itself. Unless I'm mistaken, most oil filters sold today include an internal anti-backflow valve. It helps prevent possible "dry" starts of the engine where the oil has effectively been siphoned back out of the lube-oil circuit by gravity. This would result is excessively delayed oil-pressure as the circuit has to refill upon start-up.
Again, I'm confident y'all know this. I'm just filling in for those who might not.
The anti-drainback valve found in the filter is a check-valve. It simply allows flow in one direction only. You can pump oil into the filter. The valve prevents the oil from draining right back out when you shut down the engine.
It also prevent oil flow when you connect the IN and OUT lines backward. :doh:
When pulling things apart . . . again, the other night to sort this mess out, it was noted the oil filter was CRAZY tight on the filter-head. During the then thought, final assembly of the spinny-things, one of the short-rows included installing the oil filter itself. At that time, my Son was under the truck and I had him install the filter. I specifically said "hand tight, plus a quarter turn" He said "Yup, I know Dad! My God, this isn't my first rodeo, . . .. ).
oke:When pulling things apart this go round, and discovering my blunder, it was determined the oil filter was tight to remove as a result of the reverse flow, being blocked by the anti-drainback valve. Our oil pump being of the positive-displacement design literally forced things such that the oil pressure spiked to a stupidly high pressure. The oil filter was effectively ballooning to the point the thing distorted thus hard to remove. Close inspection of the filter shows the rubber element of the anti-drainback valve was being forcefully extruded backward through one of the passages of the filter . . . .
I'm damned lucky I didn't bust something.
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