lower unit leak testing

[John Jones]

Seeing JimCT's tip on another thread about checking/changing lower unit lube reminded me of this.  The first thing I checked on my "new" to me 1993 Ocean Runner 225 was the lower unit lube.  It was, of course, milky yellow.  I went to the dealer and purchased the prop shaft seals and to Wal-Mart for some lube.  For the first time ever, I bought one of the cheap pumps that fit the quart bottles of lube.  I replaced the seals, filled the lube, then went fishing.  I logged about 42 miles on the GPS trip computer on the fishing trip.  The next day I checked the lower unit and it was milky again.  I knew I had put the seals in properly so now I needed a pressure/vacuum test.  Not wanting to spend the money for a little used tester or definately not wanting to pay a mechanic, I scrounged up some plastic tubing, fittings, valve, and a 30# gauge from my shed.  The only problem was making a leak proof connection to the fill/drain plug hole.   The lube oil pump!  I took the fill hose from the new lube pump and connected it to my conglomeration of tubing and fittings.  It worked perfectly.  I used a bicycle hand pump to pump the rig up.  However, it would not build pressure for more than a few seconds.  A mix of Dawn and water showed that the o-ring around the prop shaft bearing housing was leaking badly.  Back to the dealer.  I replaced the o-ring and pumped it up again.  It held 17 psi for 24 hours.  Then I borrowed a vacuum hand pump and gauge from an auto mechanic friend and connected it to my lube pump fill hose.  It held vacuum all afternoon.  Made my day.  No more leaking lower unit to worry about and no $$$ to a mechanic.  It only takes an hour and <$20 to replace all the seals and the o-ring.  Be sure and grease up the prop shaft and splines really well so the prop will come off easily next time.

For those without the junk collection to build a tester, this guy on eBay has the full kits for reasonable $.

http://motors.search.ebay.com/_W0QQsassZtsg54

Hope this helps someone save some $$$ or save a lower unit.

John

[JimCt]

What a great set-up!  Thought the pressure/vacuum test could only be done by "experts" with "specialized" equipment.  Now I know better.

I once thought my barometer had stopped working.  It's an expensive barometer so I made a special trip up to Boston to the Barometer Experts to have thing evaluated & repaired.  The "specialized equipment" the "technician" had for checking function was a Zip-Lock plastic bag.  He popped the barometer into the bag, zipped it closed and poked the sealed bag with his finger for the "Rising Pressure Test".  Needle rose; passed test.  For the "Falling Pressure Test" he took a pinch of the plastic bag and pulled it outward.  Needle fell; passed test.  He removed the barometer from the bag, glanced at a barometer on the wall and compared it with mine; calibration test passed.  He handed me the barometer and had the grace & common sense to say "no charge".

Two things learned:

1.  Life is either considerably more or a hell of a lot less complicated than I think.

2.  An Expert is someone from out-of-state.

[John Jones]

Good story Jim.  You lucked out.  Lessons are usually expensive.

I absolutely hate the word "expert". I have an instant mistrust of anyone with that title.

One would be amazed at what can be accomplished with a manual and a little GI-ingenuity.