This past weekend the oil pressure sending unit on my md7a sheared off its threaded stud and shot out of the block, by shear luck I was below changing out the waste bag in the engine compartment. One stunned look and rather sharp command to my wife at the helm and the engine was shut down. This all took 5 -8 seconds, the total loss of oil was 1 1/2 qts. in that short of time. we sailed in light wind to safe anchor.
I was able to tap and turn the broken end out of the block and in my kit was a bolt with the right thread/dim. The repair took 45 minutes most of that time was wiping oil from everything!
All you folks might want to check their sending units for hairline fractures. the unit itself is some alloy. lightweight and non magnetic. the volvo part number is 807078-1. cost $27.00 the engine I assume was built close to the year Milagro was, 1982. the new part can be picked up by magnet.
the fracture occured right at the base of sending unit at the last thread of stud into body.
At the rate of loss of oil another 10 seconds would have cost me thousands.
My insturment panel just has an idiot light. Now I am installing a $3.50 item from Radio Shack called a Piezo Buzzer, two of them, one down below by breaker panels and another at the instrument panel.
Tie them into sending unit wire from sending unit to idiot light.If the light comes on, the buzzer sounds. two wires on buzzer red/black hot and ground easy enough at instrument panel and a little extra wire to cabin. buzzer sounds when key is turned on prior to engaging starter, shuts down as lights go off. Fingers crossed should work.
Best Regards, Ben
P.S. the buzzer I finally decided on was the 3.0-28VDC 5mA. There is quite a selection of sounds and volumes/pitch. this one for me was the least obnoxious and could be heard above the usually din
btlandscapers@imagina.com
Heads Up on oil sending unit MD7A
Moderator: Jim Walsh