Last Sept 2019, I replaced both oil cooler lines on my 1995 855T. At 184K, it was time. I had a heck of a time with two screws. A 10mm that holds the lines against the engine block and a T30 that holds the lines to the solenoid attached to the oil pan.

Back then, all was good. I had a mechanic reinstall the 10mm bolt, it took him 5 minutes, I had tried for 2 hours.

Last Thursday, an O ring failed and oil started pouring out next to the solenoid. Arrrg. Total time today, 3.5 hours using one jack stand. The 10mm bolt must come out first! Then the solenoid is removed from the oil sump, that gives access to the T30 screw holding down the 2 oil lines.

3 surprises!

Connect the oil lines to the solenoid first, with the T30 screw. Don't cuss too much, take your time. You can finger tighten it once the threads start to catch.

The solenoid has a gasket which falls off easily. I dabbed a bit of black grease in the groove and pushed the gasket into the groove. Easy to reinstall the solenoid with the gasket in position.

The 10mm bolt. How to thread it through the two brackets and into the block? In order to get a finger and thumb up in the tight space, your body needs to be completely under the car. Not in my garage!! Never. So, a 1/4 ratchet, 6 inch extension, swivel, and 10mm socket:

Force the bolt head into the socket with a strip of paper or paper towel. It needs to fit tightly. Then slide the bolt, swivel, and extension over the sub frame back to the brackets. Slide your head under the subframe so you can look up and see what's going on. Put the bolt through the two holes, push the brackets up to line up the bolt with the hole in the block. Turn the bolt with the extension until you get tension. Slip on the ratchet and it is now a 10 minute job!!

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Keeping it running is better than buying new