Help me fix the leaks in the head area!

swooshdave · Jan 23, 2012

ludwig said:
Breather valves are nice , but if you install them just to stop leaks , you are only covering up .
" Curieren am Symtom" , like the Germans use to say .
Oil leaks are nice too , because they tell you that something is wrong .
It is perfectly possible to make a Norton engine completely oil tight , with the possible exception of the pre Mk III chaincase .
Whole libraries have been written here about leaky headgaskets .
Do a search .
Stop leaks first , then install breather ..

Not following the logic here. Even a perfectly sealed engine will eventually leak if not allowed to breath properly. Breather then fix leaks.

swooshdave · Jan 23, 2012

ludwig said:
swooshdave said:

Not following the logic here. Even a perfectly sealed engine will eventually leak if not allowed to breath properly. Breather then fix leaks.

Click to expand...

The logic here is that every engine has already some form of crankcase ventilation off the factory .

Considering that Brit bikes had factory breathers and they leaked from new you have to assume two things, the breathers didn't work and/or the sealing was insufficient from new.

hankmarx · Jan 23, 2012

One of the finer posts of the last 6 months. Maybe old hat to the Crusty Curmudgeon Norton Club , but it was clear, concise, offered detailed help, and took no potshots at other. Thank You< Guido!

Guido said:
I had all the leaks you have there and now my bike is completely drip free. This is what I did to cure it.
I had 2 pulled studs in the head up front so when I got them repaired I also surfaced the head.
I removed the 4 studs for the front rocker covers, cleaned out the threads in the head and locktited them back in.
I then took all the covers and resurfaced them by sanding them with emery cloth on a flat surface like a slab of granite going in a circular motion until it was completely flat.
You'll be able to see it.
I them removed the 2 studs in the barrels near the pushrod tunnels, cleaned out the threads with lacquer thinner.
I plugged the pushrod tunnels with paper towels as well as the stud holes and oil drain hole and used a NEW flat file and ran it flat across the surface of the barrels over the stud holes as the metal was raised around the studs holes. Just a couple of passes showed that they were raised enough to cause me concern and made me think that was one of the causes of the head leak.
After all that was done I used a shop vac to suck out the paper towels and filings.
I then loctited the 2 studs into the barrels making absolutely sure all threads were completely clean.
I took a new flame ring gasket and ever so slightly smeared hi-temp silicone on both sides of the gasket around the pushrod tunnel areas and the oil hole area.
I then assembled the head torqueing it in 3 stages.
I let it sit over night and retorqued it again before starting it up.
I let it run for 15 minutes, let it cool over night and torqued it again.
I rode it for about 50 miles nice and easy. Let it cool over night again. Torqued it again for the third time.
I did this retorque 5 times because the application of silicone to the head gasket adds some thickness to the gasket.
I also installed a reed breather I got from MikesXS http://www.mikesxs.net/products-40.html#products
It is also important to not over tighten the 2 long nuts in the front bottom of the head.

If you follow these instruction to the letter you to will be leak free.
Plus the spindle gasket and the rocker oil line copper washer should be replaced too.
That breather is real important. I've got pics on how I routed it.

pete.v · Jan 23, 2012

Guido said:
pvisseriii said:

Guido, Brevity its the soul of wit.

Click to expand...

Quoting Shakespeare are we? Nice.
Didn't mean to be bossy.

Sorry Guido. With the heat on our backs I better be careful what I say. I mean, christ man, it's sooo tempting sometimes I just can't help it.
My father always told me " Life without humour just wouldn't be very funny anymore."

Diablouph · Jan 23, 2012

I'm doing everything I can to keep from jumping on the straight line "Help me fix the leaks in the head area".

JimC · Jan 23, 2012

As far as I'm concerned, you are pissing into the wind when it comes to stopping oil leaks on the Commando, unless you first get rid of the crankcase pressure. Doesn't it make sense that having zero or negative pressure (vacuum) in the crankcase makes it easier to keep the oil inside the crankcase?

Diablouph · Jan 23, 2012

Doesn't it make sense that having zero or negative pressure (vacuum) in the crankcase makes it easier to keep the oil inside the crankcase?

Agreed, but what I believe they are saying is that you should fix the leaks first, so you have solved the basic problem and then add the vac remedy.

JimC · Jan 23, 2012

Diablouph said:
Doesn't it make sense that having zero or negative pressure (vacuum) in the crankcase makes it easier to keep the oil inside the crankcase?

Click to expand...

Agreed, but what I believe they are saying is that you should fix the leaks first, so you have solved the basic problem and then add the vac remedy.

I think there's a strong probability if you get rid of the crankcase pressure you'll find the leaks are gone too.

DogT · Jan 23, 2012

I seem to have stopped nearly all leaks that I used to have which were multiple. And I am using the timed breather off the left side. New gaskets with proper sealant (Hylomar is pretty good and doesn't stick). That said, I probably didn't get enough Hylomar on the crankcase flanges because when the Nort sits, I get a drip from the flange area. But it's several order of magnitudes better than it was. Nothing wrong with better sealant and if you can do, it a proper breather.

Dave
69S

Guido · Jan 23, 2012

pvisseriii said:
Guido said:

pvisseriii said:

Guildo, Brevity its the soul of wit.

Click to expand...

Quoting Shakespeare are we? Nice.
Didn't mean to be bossy.

Click to expand...

Sorry Guildo. With the heat on our backs I better be careful what I say. I mean, christ man, it's sooo tempting sometimes I just can't help it.
My father always told me " Life without humour just wouldn't be very funny anymore."

Who's Guildo? Sounds too much like dildo, don't you think?
Once is a typo, twice is just plain silly.

You know, you're all right. Put in a breather and the leaks will lessen. Take it apart and fix the leak and then install a breather and it will not leak again, I would hope.
Nortons have a bad rap for being leakers only because they were originally made that way.
The parts that leak are:
The head, whether it's the head gasket, oil lines ,cover gaskets.
The tach drive.
The gear box cover.
The primary cover.
Or the swingarm pivot.
We as a community have come up with some nice mods to combat these issues.
Part of the fun is winning these battles against leaks which I gotta tell ya is as good as sex and just as satisfying.

pete.v · Jan 23, 2012

Sorry Guido, corrections made.

Hobot · Jan 23, 2012

My pre-Ms Peel Combat had 14 leak sites and was only reason I thought I'd go through her and learn the ropes with online hand holding. Oh brother if I'd only known then -...

Rocker pindle covers and bolts are another famous weeper.
Some the worse looking head mess can all come form fork seals.
Some 850's heads are cast porous to leak right out the metal pores.
Factory supplied chain oiler gave proper amount of oil to keep chain flushed out of wear particles but almost non existent now even in 'bone stock' ones.

Matt Spencer · Jan 23, 2012

If you gert it real clean , and dont put any in , and dont start it , she might not leak any . :lol:

The Breather trick , is it doubles the case volume ( ish ) improves timing side lube , and throw off .WITH
the breather in the Magneto Position ( What do the Dudes with Magnetos Do Then :lol: )

OTHERWISE , put a new gasket in the valve cover / s and clean the tacho Drive . I think throwing TWO 'O' rings
in there sometimes cures that . Too

." Pliobond " is pretty Good Gasket Cement .Its not pretty good getting it of though .( Std use in NZ in the 80s , oil tight )

Guido · Jan 24, 2012

Here's how I routed mine.

rvich · Jan 24, 2012

commando-head-barrels-studs-too-short-t11659-30.html?hilit=head studs

kwoody51 · Jan 24, 2012

Thanks everyone for all the help! I am reading post and I am paying attention, I was just soliciting additional insight/ confirmation of the methods. Sounds like I have some researching to get to the bottom of all the other leaking areas that I have that have been previously discussed on the board.

I'm sorry that I haven't been on lately to post, I've got 3 and 1 year old girls at home so my daily free time is limited. I check in on the post at work, on my phone, but can't really post much.

Guido - it appears that your breather is coming from the timing cover, is this just a difference in the years of engines? My breather is low on the back of the engine on the magneto side.

Is the area in my photo below coming from the tach drive or is it another fix area?!

On the topic of crank pressure, I had an interesting encounter on my Aprilia 990 V-twin. I installed a catch bottle to get the residual oil from the breather, the catch bottle wasn't vented properly and I had all sorts of weird issues. Valve covers leaking, shifter seal leaking, water pump oil seal leaking and..... with lots of high RPM running the clutch started slipping (had a vacuum slipper clutch). Took a couple of week but tracked the issue down to the improperly vented catch can. Long and short of it, excessive pressure in the crank was causing lots and lots of leaks and other issues.

DogT · Jan 24, 2012

Yeah, if you don't vent the oil tank or the crank, things get strange. I put a catch bottle off my 69 from the oil tank breather that went into the air filter which was always leaking oil into the air filter and gearbox. Now it leaks into the catch bottle and no more leaks into the air filter. But this is an early bike. At least now I don't have oil dripping off the air filter onto the gearbox and down on the road. anymore. Life is good.

Dave
69S

swooshdave · Jan 24, 2012

kwoody51 said:
Guido - it appears that your breather is coming from the timing cover, is this just a difference in the years of engines? My breather is low on the back of the engine on the magneto side.

Best guess is that you have a 72 model.

I wonder if the breather is clogged. Might be worth it to make sure. See if this video helps.

[video]http://www.youtube.com/watch?v=Ti9PvFfsfm0[/video]

You should be be able to feel the breathing at the oil tank.

kwoody51 · Jan 24, 2012

Thanks for the video! I'll have to check those things. Based on the condition of that bike I'm going to assume that is "normal" . Is this correct?

I actually took the hose off the tank and sucked/ blew through it, everything seemed OK. There is definitely a one way valve installed, I also confirmed that the breather form the engine is working.

I'm probably going to get the XS breather to replace the cheap looking plastic one that is there now.

Help me fix the leaks in the head area!

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