Author Topic: sudden oil expulsion  (Read 875 times)

Offline Frenchy

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sudden oil expulsion
« on: 12.09. 2012 20:24 »
I've been enjoying my time on my A7.  Unfortunately, while at a stop light yesterday I noticed that it was spewing out the oil breather hole.  The oil tank still has oil returning to it, so I'm assuming the pump still works.  A local guy suggested that the check valve may be stuck.  Sound reasonable?  If that is the case how do I go about fixing the problem?   
1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline fido

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Re: sudden oil expulsion
« Reply #1 on: 13.09. 2012 06:49 »
If you do a search of this site for Pressure Relief Valve you will find quite a few previous discussions on the matter. Yours may just need dismantling and cleaning but SRM manufacture a replacement one which looks similar to the Triumph type:
http://www.a7a10.net/forum/index.php/topic,925.msg6206/topicseen.html#msg6206
The advantage of the Triumph one is you can see by the plunger position whether it's open or closed.

Online muskrat

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Re: sudden oil expulsion
« Reply #2 on: 13.09. 2012 07:53 »
G'day Frenchy,
                    did you check and top up the oil tank after a week or two of not starting her? She may have wet sumped a bit and is now over full and blowing it out the breather.
 Funny the last time I did that it was fine for about 60 miles but when I stopped and let it idle it poured out!
Cheers
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Online orabanda

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Re: sudden oil expulsion
« Reply #3 on: 13.09. 2012 09:28 »
Me too; been there, done that!

Online bsa-bill

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Re: sudden oil expulsion
« Reply #4 on: 13.09. 2012 11:09 »
Quote
spewing out the oil breather hole.

Good prognosis Musky provided French is talking about the same breather, for some reason I first presumed the crankcase breather, probably I've just read far too many wet sumping mails *smiley4*
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Frenchy

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Re: sudden oil expulsion
« Reply #5 on: 13.09. 2012 14:43 »
Yes, it was the crankcase breather.  The bike hasn't sat for more than a day without being ridden, also.

I pulled the sump plate last night, drained the oil, and cleaned the screen.  I'm maybe 200 miles into a top end rebuild, so there was a slight amount of fine metal caught in the screen.  There were also tiny bits of rubber gasket in the screen and in the crankcase oil.  I put it back together and refilled with fresh oil and everything was fine.  I rode it for a few minutes around the neighborhood and everything seemed normal. The screen in the oil tank looked pretty clean.  I'll be vigilant about oil changes for a while.

I've been advised to inspect the sump check valve.  Where is it, how do I get to it, what's it look like, etc.?
1957 A7 bobber, swing arm
Columbus, Ohio, US

Offline duTch

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Re: sudden oil expulsion
« Reply #6 on: 13.09. 2012 22:31 »
G'day Frechy,
              The sump check valve is inside the sump orifice, it's a ball inside the scavenge pipe sticking down which goes through the hole in the cover screen,so you need to get on hands and knees to diddle with it or get a mirror(I have a couple of old side mirrors that are invaluable or buy a telescopic one on a stick).
 There's not much you can do except poke it to ensure the ball isn't sticking, other than take the oil pump off and blow air back through the pickup pipe while holding the ball open,hopefully you won't need to do that, though you could poke something in to hold it open fro a while and allow any crud to drain out?
    It's all been discussed here recently if you search wet sumping.

 It's also been pointed out that if you have a magnetic plug in the cover, it can hold the ball closed, so needs to be orientated as far from the pick-up as possible.
 The 'anti-wet-sump' valve is behind the oil pump and can only be accessed from inside the crank case, meaning full strip down, in my opinion unnecessary unless it's real bad.

 I hope that's helpful.
 Cheers, duTch
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
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Offline Frenchy

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Re: sudden oil expulsion
« Reply #7 on: 14.09. 2012 20:34 »
Thanks, Dutch.  I fiddled with it a bit and cleaned some gunk out, so it appears I'm fine for now. 

It's been a stressful week at work, so as I sat in traffic watching my plugged up engine coughing up oil I thought, "me too, little buddy."
1957 A7 bobber, swing arm
Columbus, Ohio, US