Airhead - weird oil leak

[MickDB1]

Hmmm ... tubes?
So ... Mikeyboy was right?


it was the push rod tubes then Mick?

Not at all wanting to be a Donald T = but it looks like it = A LOT - me being me though - I will have to blank off the 4 rocker retaining holes and fit the blacking plate I have made to the base the refit a rocker cover = so to test the whole jobby in 1 -
They are down in manuals as the protection tubes - as Mikey says not the push rod tubes - which are nearer the cranckcase - part of the barrel assembly

Thanks Pete for your input = Great site is this - puts up we me

 

[Posh Pete]

Every day’s a school day, Mick! ... if you’re not making mistakes, you’re not learning or trying hard enough!

I make plenty of mistakes!

 

[MickDB1]

Not so good today = took the dodgyist "leakin" head and made me a lexan blanking plate tapped a connection to pressurise with replaced rocker cover so all the top end can be pressured (all joints on tube on the top tubes would be tested). F All leaks @ 35 psi - apart from a bit from rocker cover - Me torque wrench is actin up = maybe a clue here !
Maybe tomorra - maybe next - more if I find out

 

[MickDB1]

Every day’s a school day, Mick! ... if you’re not making mistakes, you’re not learning or trying hard enough!

I make plenty of mistakes!

I tell folks there is only 3 ways to lean owt
It cost yer
It hurts yer
Or yer listen

Not many does last un first

 

[mikeyboy]

My 5 pennies worth,
The head tubes were pretty corroded mick.
And ,You’re not pressure testing at engine temp..
That aside,the pressurised oil feeds are on the top two studs each side,
The oil leak from your description is underneath the heads and barrels,the head and barrel push rod tubes are just drains.
So,,
You’ve either got excess oil pressure and it’s somehow getting to the lower part?(unlikely?)
Or possibly excess crankcase pressure
Assuming the heads are torqued correctly and the gaskets are good.
Degrease everything and reassemble,dust the underside with talc,
Make sure the valve gear,rocker shafts etc are fitted correctly,
Get an oil pressure gauge on it,and fire it up,let’s see how much OP it has.
Once it’s warmed unscrew the dipstick,make sure it’s not pressuring the crankcase,
Could be something as simple as a trapped breather pipe under the starter cover.
The talc may well make it easier to see the leak if you can get a volenteer to lie under it when it’s fired up

 

[barny]

The talc is a good point from Mikey. Once the area around the "oil leak" is cleaned up any cracking will show up if sprayed with talc due to the residual oil in the crack being drawn out. It used to work on aircraft although a lot more expensive with dye repentant but the principle is the same.

 

[Big-G]

Pal just sorted an oil leak on his my20 AT using ultraviolet oil dye. It revealed the slightest trace and at last the dealer was able to repair.

https://www.ebay.co.uk/itm/Ring-Gar...046658&hash=item56be991bcb:g:RYoAAOSwkXBdlzna

 

[MickDB1]

Thanks again for some top tips and ideas.
Another one gone - I repaired / services the torque wrench without altering the original config , when set at 23 lb per foot it is actually 21 lb @ foot.
So I hadn't under torqued it well not by much - I originally nipped it all up to 25Ib per foot !!
I thought right at the start that there may be a blockage somewhere on return to filter - but if its pumping and keeping low oil light off it must be getting enough supply shirley.
New filter and fresh oil
Checked the breather couple o days ago - It pumps/ releases out to the atmosphere at low level under swingin arm not back to the air box and that just pops- like a pup pup pup and drips a bit of condense at start up - Not checked it at revs mind (me arms arnt long enough) so I think that relieving ok
I did, when it were warmed up undo the oil filler cap when engine was at a fetish tickover - not a great idea = it did spray atomised oil about - I dont know why I didnt expect that.
Didn't seem and real pressure or owt though.
I thought about the not tested at high temp too - cant do any hot tests easy - the talc is an interesting idea
O and I had removed intake stubs and checked faces of heads on ultra fine grinding paper on a block of marble = couldn't find glass
More as I do it - and again thanks for idea,s and stuff

 

[MickDB1]

Another few hrs of interest in me shed
Tested the engine breather at half thrash still just a very slight put put.
Made a tester for the crankcase and tested CC at half thrash 1 - 2 psi showin on me gauge.
Tested when engine warm
So pistons aren't passin to crankcase
here's a pic of me tester = it was held down into oil filler hole and the tapered shoulder on elbow fitted perfect -
So it is most likely the tubes perforated or joints on them failin at high temp
Removed the tubes ready for some newuns
It is a bugger of a job to say the least.
Needs targeted percussion -
Thanks again

 

[timeandtide]

Glad it’s keeping you out of mischief Mick!
If you need another pair of hands sometime just give me a shout.

 

[MickDB1]

Thank you Richard for your great offer.
All I can do now is put both "spare heads" on the bike and go for a rideabout.
At least that will prove they ( the spare uns) are good uns.
May pop to see a nice chap down Melton way with some bits for an expert coat O lookin at
Better take a Xmas card we me
I forgot I had them heads so that were good.
I now have some interesting test equipment - if anyone needs them to use you are welcome - I will save um in me shed loft -
they will come in handy
= even if I never use um