How to Bypass the Oil Filter

The adapter plate sandwiches in between the filter and block.

Bypassing an oil filter is easy when you have the right parts. Most cars have a closed lubrication system; the oil pump sucks oil from the sump, sends it through the filter and pushes it through the oil channels to the top of the engine, where it then trickles back down into the sump. Many enthusiasts like to tap into this system between the engine and the oil filter to install a bypass line, which permits use of an external oil cooler (oil radiator), oil reservoir or remote filter for easier maintenance at the racetrack.

Things You'll Need

• Oil filter bypass kit
• Full set of metric and standard wrenches
• Oil filter wrench
• Deep well socket to match the adapter's plate size
• Teflon tape
• Shop rag
• Medium-strength thread-locker (optional)

Instructions

1. Remove the oil filter. In most cases, this will require only a standard rubber, strap-type oil filter wrench, but that may not be enough if your filter is really stuck. If it won't come loose, put a small dimple in one side with the claw end of a hammer. Place the tip of a screwdriver in the dimple and hit the back into the tip pokes out the other side. You can now use the screwdriver handle for leverage to spin the filter.

2. Clean the oil filter mating surface with a clean, lint-free rag. You can use a little bit of gasoline, carburetor cleaner or rubbing alcohol to clean the last of the residue.

3. Wrap the threads of the oil filter bypass kit's hose ends with Teflon tape and thread them into the adapter receptacles. If using elbow fittings, both should end up oriented downwards when tightened to the manufacturer's specifications.

4. Coat the O-ring on the adapter with fresh engine oil and slip it in place of the oil filter. Slide the adapter and retaining nut over the threaded oil filter boss and tighten it down to manufacturer's specs. If you're not planning on removing the adapter any time soon, you might want to consider thoroughly cleaning the threads with carburetor cleaner and a rag, then applying a few drops of medium-strength (usually blue) thread-locker before installing the nut.

5. Install the adapter end cap over the oil filter boss if you're running a remote oil filter setup. End cap installation will vary by manufacturer. Some will utilize another nut on top of the oil filter boss while others will use three or four separate bolts cast into the adapter plate housing. If you're only installing the adapter plate to run an oil cooler or reservoir, then you'll simply screw a new oil filter over the top of the adapter plate.

6. Install the bypass lines onto the pre-installed line fittings. Many kits will require Teflon tape, but some will utilize a gasket/O-ring seal that doesn't require Teflon tape.

References

• Moss Motors: Oil Cooler Install Guide (PDF)
• Hybrid Honda Performance: Oil Cooler Install
• Automotive Articles: Oil Cooler Install