The Proverbial Oil Pressure Sending Unit Leak

After wiping down the whole engine block a few weeks ago, I notice this morning that a fine film of oil is covering the front left of the engine block and all the components around the oil filter. I start feeling around and under components and when I reached down under a little domed looking thing near the oil filter I felt liquid on my finger which smelled like oil. I decided I had better find out what this little thing with a wire coming out of the end is and how to fix what must be a very slow, but persistent oil leak that is getting sprayed by the air from the fan and covering Old Blues front left engine block in a fine coat of oil.

I look up the engine in the shop manuals and find I am looking a the Oil Pressure Gauge Sending Unit. A single adapter with both the oil pressure gauge and the warning (idiot) light sending units mounted on it.  The adapter sticks up from where the oil filter connects to the oil pump and has two holes, one for a round button looking unit with a simple flat connector and the other looks kind of like a canister with a round female connector plugged into the end. Both screw into the adapter and I think this may be the source of my drip. 

From the FE Forums I find Bill mentions numerous times that "The oil pressure gauge sending unit is notorious for leaking and getting gummed up with dirty oil. Once this occurs, the little charmer no longer works. Note: When there's an oil pressure gauge and an oil warning (idiot) light on the dash board, there are TWO sending units, both thread into an adapter (C5TZ-9B339-B) that threads into the engine block.

The oil pressure sending unit is much larger (has a domed head) than the oil warning light sending unit."

E4ZZ-9278-A (replaced: B7T-9278-A, C7ZZ-9278-A & C9ZZ-9278-A) .. Oil Pressure Sending Unit-Use with Pressure Gauge (Motorcraft SW-1547B).

B6AZ-9278-B (replaced B6A-9278-B) .. Oil Sending Unit-Use with Warning Lamp (Motorcraft SW-667)."

I pulled the domed unit by pulling the post connector and tucking the little wire out of the way, then getting a wrench on the square brass block above the threads. I removed the sending unit (this one's for the Oil pressure gauge), and while it was off the engine I removed as much of the blue paint as I could. I presume whoever painted the engine block when it was rebuilt also painted the oil pressure sending units. I then wrapped the threads with teflon tape ensuring the thread edges were exposed for grounding and remounted the unit into the adapter.

I drove around yesterday in the unusual spring like weather and when I got home took a look (and feel) at the unit. No leaks and my now wiped down engine block was oil free. 

Driving To the Golf Course

This afternoon Grace and I threw the irons into the bed and drove Ole Blue out to the driving range north of town. Grace was getting a lesson from the local Pro and since it was a sunny winter day we decided to let the truck warm up a bit. On the way through town we stopped at Starbucks for coffee and as I was parallel parking along Petaluma Boulevard I noticed the brakes getting mushy as I cranked the old steering wheel to maneuver into the space we found in front of LaLa's Ice cream shop.

I would pull forward, depress the brake pedal and then crank the steering wheel, let up on the brake pedal, roll a foot or two and then do it all over in the other direction slipping Ole Blue into the space just big enough for her length.

It was during this exercise that I noticed while I cranked the steering wheel with brake pedal depressed that after a few seconds the pedal would move towards the front of the truck. I am fearful this is indicative of either air in the lines (After all this time?)  or some other issue with the brake cylinders. Hmmmm ... I will add this to the list of things to check out in the next few weeks.