Topic: 76 CB550 Oil Leak Revisited....3rd time....

[L.A. Nomad........]

1976 CB550k

I've had a leaky left side oil pump for a while. I've ordered 2x Oil pump Oil-ring sets from a SOHC4 member in England. Pump cover(3 holes) needs special size o-ring.

I've replaced all pump O-rings, still had leak. But I left out a dowel. Rechecked, everything good for a couple of weeks. Oil leaks again!

I replaced the pump cover with 3 holes, thought it might be warped. Then I used my 2nd new O-ring (special size), a week later oil is dripping again.

Every time I remove the pump/sprocket cover 1/2 cup oil pours out.

Assuming I did everything right, do you guys think it might be the pressure sensor?
I'm ready to replace the whole pump! But that doesn't seem logical, but oil is leaking from that area! Anyone have a pressure sensor leak oil before???

Thanks!

Los Angeles!  Motorcycle Swap Meet June 28th 2009!  10x10 spaces are only $10, first come first serve! Expect cafe themed bikes, Asian and European parts...... Just show up, but send your name and number to the email on flyer.



 

[brianzenk]

I have a cb550 1976
I replaced the seal where the shifter goes into the case
because of a slow oil leak.
The pressure sensor is sealed and should be in tight.
After I lube the chain and ride hard oil coats the inside
of the case and drips out when I stop and that makes me think I have
a problem where there is none.
There is another oil seal behind the chain gear but I have a spare on
hand but have not replaced it yet.
 

[Sporkfly]

I've seen pressure sensors leak, and the cover o-ring is a b****. I haven't had any issues with the one I purchased from BryanJ so far, though. I did screw up my pressure sensor though, granted it wasn't an OEM component, it was actually for an accord. Ah, well. Anyway, replace the sensor and maybe put some hi-temp silicone on the cover side where the O-ring is, don't put it on sticky - let it set first. Even with my new O-ring I have a very slight drip, but certainly not in the 1/2 cup range.

[bryanj]

I am nearly out of the first 100 i bought and nobody has come back saying they didnt work yet. I know the cap on the end of the relief valve can crack if overtightened, there was even a bulletin out about it and i have had several oil pressure sensors leak with age.

All i can Suggest is carefull inspection for warpage and cracks/damage, if the "O" rings are faulty let me know direct and I'll replace them FOC