Author Topic: Oil leaks.  (Read 1311 times)

Offline Zander

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Oil leaks.
« on: 22.01. 2017 09:47 »
My Gold Flash, which I got last Monday has been marking it's territory, with oil appearing on the floor in three places.
First one I looked at was oil from the flow and return pipe area. Nipping up the connections appear to have solved that one.
The second one is oil running from the top of the timing cover, at the front, which seems to be coming from the joint between
the dynamo and casing. I'm a bit puzzled by this, as I was under the impression that the dynamo chain was greased and not lubricated by an oil feed.  From other posts on here, it looks like I'll have to make sure its not coming from the inner casing joint.
The third leak is from the area of the rear of the primary drive cover, although it may be from the gear box, as there is oil in the centre stand spindle area.
The dynamo isn't charging, so having tested it in situ, it was necessary to remove it from the bike which suited me, as I could inspect the cork seal which is where I think / thought the oil was coming from.  The seal is in good condition, although it appears to be compressed to the extent that it's debatable whether it stands proud of the dynamo flange. A PO had put a smear of silicone sealant on it.  Any clues / guidance gratefully received!  Thank you.
'59 GF

Online bikerbob

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Re: Oil leaks.
« Reply #1 on: 22.01. 2017 10:58 »
First the oil leak from dynamo area while you have the dynamo off you should  look at where the oil is coming from as well as possible failure of the inner case gasket there is also the possibility of oil coming in behind the large chain sprocket that sprocket is bolted to the idler pinion behind the inner case  there should be a cork seal behind that sprocket, now it is debateable wether this seal is required as the bush in the inner timing has a reverse scroll machined into it so any oil would be sent back into the inner case but if the scroll is blocked with gunge then the oil can run into the dynamo compartment. When I had my Gold Flash some years ago it never had a seal behind the sprocket and oil did not get into the dynamo casing my presnt A7 does have the seal however it also has a toothed belt drive and the seal came as part of the kit. The problem with leak behind the primary could be caused by a few things too much oil in the primary case, the felt washer could have failed this is fitted behind the sliding plate behind the clutch. Also it could gearbox oil in which case it could be the gearbox oil seal or the bushes in the constant mesh gear oil can also sometimes leak past these bushes if the bike is on the side stand.

Online Klaus

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Re: Oil leaks.
« Reply #2 on: 22.01. 2017 11:20 »
Hi Zander,
welcome to this helpfull forum.
First lokation, please check the oilpipes also at the oilttank. Sometimes they get losen by vibrations and leck some little oil runing down the pipe on the backside. It also can happen that oil coming from the magnetofixing, and dripping down where the oilfeed is.

I think there a bad news with the oil coming out from the dyno. So I gues the idler pinionbush is heavy worn out, so oil is coming from the crankcase and filled up the the casing.

I assume the oildrops from at the end of the primaricover is from the enginebreather. You can find the end of the breather line left hand under the the cambush the little round casing next to the magnetocap. Blow by will spread some oil at the backside to the gearbox sprocket and than dripped down.
You can sort out if its gearbox oil or engineoil by smelling and color.

cheers Klaus


If you think, everything is under control, you are not fast enought.

Offline Zander

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Re: Oil leaks.
« Reply #3 on: 22.01. 2017 20:07 »
Thanks for your comments bb and Klaus.  Sounds like the bike needs a bit more than a tickle here and there!  I had a look at the large dynamo sprocket and found it moves in and out by about 1 mm (endfloat), but there's not much movement clearance- wise.
The PO had also used silicone on the case gasket and I found a fair dollop of it in one of the chamber corners. Not good.  Re the dynamo, the comm seems ok,  but the field coil is not showing any resistance.  I've run it als a motor ok, but the "spin" test gave no readings, and the bulb failed to light on that test.  Overall condition of the dynamo internals and exterior is like new.  I also flashed it, to no effect. Unless I've missed something, looks like I'll be ordering a new coil, and if that works, I'll be chuffed.


'59 GF

Offline trevinoz

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Re: Oil leaks.
« Reply #4 on: 22.01. 2017 20:22 »
I wouldn't think that the dynamo would motor too well if the field coil is open circuit.

Offline Zander

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Re: Oil leaks.
« Reply #5 on: 23.01. 2017 07:18 »
I wouldn't think that the dynamo would motor too well if the field coil is open circuit.

I must  admit, the fact that it motored, albeit fairly slowly, was a surprise, but then, electrics to me represent the Dark Arts! 
'59 GF

Online bikerbob

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Re: Oil leaks.
« Reply #6 on: 23.01. 2017 10:15 »
Before you go to expense of buying new parts go the subject on this website Lucas electrical ignition and look at my problems under the post Dynamo confused. I overhauled my Dynamo fitting new field coils armature bushes and bearings and connected the wires up as before the strip down but it would not charge even after flashing when the dynamo was running under test as a motor it was running clockwise it needs to run anti clockwisethis was solved by reversing the brush terminals now charges OK.

Offline Zander

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Re: Oil leaks.
« Reply #7 on: 23.01. 2017 10:31 »
I'll certainly do as you suggest, be. Thank you. *wink2*
'59 GF

Offline Scott and Jay

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Re: Oil leaks.
« Reply #8 on: 24.01. 2017 01:26 »
Hi Zander and welcome,

If it's the later A10 with the drive-side engine oil seal behind the cush drive - you might like to check this is still in place. Otherwise engine oil will fill up the primary. Forcing out of this oil seal, in turn, would be caused by excessive crankcase pressure - which I went through...

Offline Zander

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Re: Oil leaks.
« Reply #9 on: 24.01. 2017 10:13 »
Hi Zander and welcome,

If it's the later A10 with the drive-side engine oil seal behind the cush drive - you might like to check this is still in place. Otherwise engine oil will fill up the primary. Forcing out of this oil seal, in turn, would be caused by excessive crankcase pressure - which I went through...

I've yet to tackle the primary chaincase as I've been concentrating on the dynamo.
Today I'll have the inner timing case off to see what's going on there re the idler bushes.
I think the engine is 1960 but not sure, so will bear in mind your advice. Thank you👍
'59 GF

Offline Zander

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Re: Oil leaks.
« Reply #10 on: 24.01. 2017 14:17 »
Update:   It's a fact that when I got the bike, after running the engine for a few minutes, oil started running from the area of the dynamo seal down the front of the timing cover.  it's got to be coming from somewhere, so I've removed the inner timing cover and checked the idler bush and gear, neither of which seem to be badly worn.  The grooves on the idler bush are clear and there is, apart from 1mm end float, normal running clearance between shaft and bush. As far as I can make out, there shouldn't be any oil in the area of the dynamo drive chamber, so I suppose perhaps the idler bush should be a tighter fit than mine.  Sadly, it's not as clear cut as I would have liked, but I don't think I've any option than to buy a new one and try it.

'59 GF

Offline TT John

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Re: Oil leaks.
« Reply #11 on: 24.01. 2017 16:02 »
Zander.

Your quite correct in saying there should not be any oil in the dynamo compartment, so check your gasket that side also inspect the condition of the web inside the cover to make sure that it is sealing okay, the one that runs from the top down to just above the oil pump housing and make sure the web is complete. Sorry if I'm teaching you to suck eggs but there are some things which are so simple you can miss.

TTJohn

Online bikerbob

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Re: Oil leaks.
« Reply #12 on: 24.01. 2017 16:14 »
Before you go to the bother and expense of a new bush which may not solve your problem, you say you have 1mm end float that is too much. Some 20 odd years ago when I did my first restoration on a Gold Flash I was concerned at the time that I could not buy the cork oil seal from any dealers at that time . I wrote to the tech consultant for the A10 at the BSA owners club who has now sadly passed away he was very helpful to me a number of times, he said that the seal was not really needed but if you did away with it you should put a shim between the idler gear and the inner case to take up the end float that would be present without the seal he did say how much the end float should be but I cannot remember but it was only a few thou. Why don't you try fitting a seal they are only made of cork the one on my A7 which came with the belt drive kit proved to be too thick so I reduced it's thickness down to around 1/16" thick it takes up the end play and also acts as a seal. The funny thing about these old bikes is what works on one bike is no guarantee that it will work on all.

Offline Zander

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Re: Oil leaks.
« Reply #13 on: 24.01. 2017 17:27 »
I tried a crude experiment to see if oil leaks from the end of the bush and the idler gear and it does, so a new bush may be needed.  I've also been thinking of ways to fit an oil seal, and I like the idea of the cork one, as I don't think it's possible to fit a lipped seal.
I'll also be having a close look at the faces and webs.  Have sourced most of the items needed from SRM, so may place an order tomorrow.
Thanks for your help BBC and TT John👍

'59 GF

Offline Zander

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Re: Oil leaks.
« Reply #14 on: 24.01. 2017 17:30 »
BBC?  Predictive text strikes again! Sorry, bikerbob🏍
'59 GF