ISX and Bypass Oil Filter Systems

[ne14jpn]

(02-25-2026 )ne14jpn Wrote:  Tech question - Can I use "Port Location #1" for bypass filter supply pressure feed line referenced from the Engine Oil Cooler picture in Post #9 of this thread?

In Post #15, Rawze mention the ability to use Port #3 or 5 for oil supply line. He had heat issues from the turbo with #3 and ended up using #5 which seems to be the most common port for supply. My issue is clearance to #5 from the turbo outlet charge air tube in my application. The chassis is a 2005 Volvo VNL 780 with the CM870 ISX and Eaton 13 speed. There is not enough room to install a -8 fitting of any sort on my truck in that location.

Port 1 is wide open so please let me know if that will provide a supply feed to the bypass filter? Thanks!

Following up with an update - Port 1 is NOT oil! Found this out the hard way when coolant came rushing out. Hope this saves someone the trouble of learning the hard way too. Those plugs can be extremely difficult to get out. I ended up using an air hammer to break them loose after liberal amounts of heat and penetrating oil. They're 6mm hexes and very easy to strip out if you aren't careful.

I was able to get both metric o-ring to -8 AN adapters installed and will hopefully be able to finish up mounting the filter housing and plumbing this weekend. Note on the larger metric fitting that is return and installs in the block above the oil pan: be mindful of the hex on the fitting hitting the block as you tighten it up. I felt it touching as it was getting tight. I removed, took it to the lathe to chamfer the edge and reinstalled with no issue. Doesn't take much to make it happy.

I ended up using Port #3 with a straight fitting and planning to use a 90* end on the hose to get it away from the turbo heat. @Rawze - when you had issues with heat was the fitting a straight? I could see how that would be very close to the housing.