A cb550K3 oil pump question

[nairb]

I have had my cb550k3 from new, so I know its history...... Its done 46k miles.  In the last couple of 1000 miles its developed an oil leak from somewhere under the engine.
I have put up with it until now.  I finally decided, after an oil/filter changes to sort it out.  After cleaning up the underside of the engine it "looked" like the oil was coming from the LH sprocket cover.

When I took the LH sprocket cover off a small cup full of oil came out of the oil pump area.  Now I have had that LH cover off several times over the years, so I know there should not be any oil in that quantity. 
Here is a pic of the pump.  Untouched from the factory....
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Anybody had a similar issue.  A common fault?.  I have not done anything to it yet.  At least I have found the oil leak.
Ta
Nairb

 

[Johnwebley]

Yes,

I think 50 years old O rings start to leak

I got replacement from Nurse Julie



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[McCabe-Thiele (Ted)]

Could it be the oil pressure switch?

[Rayzerman]

I'd clean the area up with degreaser or solvent such as mineral spirits, spritz on some rubbing alcohol to rinse it clean... then spray some foot powder on the area, and any leak will leave traces of its path in the foot powder.

[Bryanj]

Sometimes the switch on top, sometimes the cover O ring which Honda do not list.
A lot of years ago i spent some time working out what size O ring would cure it and did sell kits but my supplier changed his rules and would only sell in lots of 100 so i gave up but Nurse Julie does a kit of O rings for the pump at a reasonable price and even does deals for forum members.

HINT
Use an impact screwdriver to loosen the 3 countersunk cover screws BEFORE you remove the pump

[nairb]

An update:-  I cleaned any trace of oil from the pump and with the cover off I started the engine to see if it was possible to find where the oil was leaking from.
Pic of the result.

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After less than a minute it was dripping oil, and it looks like from the bottom of the pump.  The pump has never been worked on or apart so all seals/gaskets should be intact.  Even after 50 years??.

Do oil pumps really go wrong?.

[deltarider]

Do oil pumps really go wrong?.

Depends on the oil maybe. When mine leaked (Pyrenees), I had Mobil 1 for the first time, a full synthetic oil. A Spanish workshop allowed me to do the job myself. The boss was very friendly, went out on his bike to get new seals for me.
Ever since I have used oil that keeps rubber parts supple.

[Bryanj]

Oil pumps rarely go wrong but 50 year old O rings get hard, deteriorate and leak along with the diaphragm in the switch gets lass pliable and cracks so leaks

[nairb]

Hurrray,  After applying a set of oil pump seals from the forums own Nurse (very quickly delivered) the oil leaks have stopped.  Very satisfying when a fix is applied and it works.  100+ miles and no drips at all.