Help me fix the leaks in the head area!

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Help me fix the leaks in the head area!

Postby kwoody51 » Sun Jan 22, 2012 3:31 pm

It's winter and we all know what that means.... project time. I've been eying these "leaks" for a while but been too lazy to do anything.

Is a gasket swap all that's needed to address these? As far as I know the bike has the stock breather. Don't know if that is a "key" thing to change to help alleviate internal pressure and thus avoid these type of leaks.

Both of these photos are on the right/ ignition, side of the bike.

Image
Image
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Re: Help me fix the leaks in the head area!

Postby jsouthard » Sun Jan 22, 2012 4:00 pm

I would start buy ordering these silicone gaskets.

http://www.rockypointcycle.com/Merchant ... y_Code=N10

While you wait for them to arrive you should check and make sure the surface is flush and clean. I can't tell if it's also coming out of your rockers? Might be time for a new gasket there as well?
Joe

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1958 Norton Dominator Model 77

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Re: Help me fix the leaks in the head area!

Postby 1up3down » Sun Jan 22, 2012 4:13 pm

Yes on getting some new rocker cover gaskets.

As you also know from reading this forum, many people here report back about the elimination of various engine
related leaks by installing a simple, cheap, one way valve in the breather line.

I assume you have one installed already.
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Re: Help me fix the leaks in the head area!

Postby DogT » Sun Jan 22, 2012 4:25 pm

I got some neoprene gaskets for the rocker covers and they were not satisfactory. The silicone ones may be better. What I did was use a standard cheap paper gasket with silicone on the cover side and into the studs (or bolts if that's what you're using), and grease or whatever on the engine side. It seems to help, at least I don't have the oil leaking any more. It can help to carve the gaskets to fit the cover so oil doesn't sit there inside waiting to leak out.

Tach drive needs an o-ring mod to the tach drive gizmo.

Dave
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Re: Help me fix the leaks in the head area!

Postby splatt » Sun Jan 22, 2012 5:05 pm

Due to high quality design all of the threads are drilled all the way through into the inside of the head, exhaust rocker cover studs, rocker spindle cover bolts and the two front head studs, oil will weep out /pour out of them, loctite on the studs and bolts will help slow the leaks
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Re: Help me fix the leaks in the head area!

Postby rpatton » Sun Jan 22, 2012 5:07 pm

+1 on the silicone gaskets. Would have been nice if they made them in black or gray. While you're at it get the one for the oil filler cap.

http://www.rockypointcycle.com/Merchant ... y_Code=N10
Bob

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Re: Help me fix the leaks in the head area!

Postby bmwbob » Sun Jan 22, 2012 6:47 pm

I use dry gaskets on the rocker covers and put a little RTV in the nuts to stop the oil migrating up the threads. For the head a, very little sealer around the push rod tubes and RTV on the inner 3 nut by the push rods and follow torquing procedure at 35 lbs! No oil leaks!
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Re: Help me fix the leaks in the head area!

Postby Johnnymac » Sun Jan 22, 2012 7:30 pm

I have the neoprene rocker gaskets from Commando Specialties. Haven't had a leak since I installed them.
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Re: Help me fix the leaks in the head area!

Postby hobot » Sun Jan 22, 2012 7:38 pm

Highly recommend the red silly con gaskets, which lasted through a bunch of valve adjustments on two engines since 2001, but now see them coming apart from the cover pinch under the nuts. Still sealing though. New set will be ordered for next decades use. I guess one could stain the things black to hide em but I like the pin stripe high light that's oil dry. Btw Hylomar applied well is hard to beat any where a seal needed w/o gluing it together.
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Re: Help me fix the leaks in the head area!

Postby Guido » Sun Jan 22, 2012 8:23 pm

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.
'73 850 COMMANDO
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Re: Help me fix the leaks in the head area!

Postby bmwbob » Sun Jan 22, 2012 8:31 pm

Johnnymac wrote:I have the neoprene rocker gaskets from Commando Specialties. Haven't had a leak since I installed them.


Maybe the studs don't break into the valve area on yours
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Re: Help me fix the leaks in the head area!

Postby kwoody51 » Sun Jan 22, 2012 8:56 pm

I do have a one way breather valve, but it appears to just be a plastic bodied unit, nothing special like the reed valve XS one.

I'll order up some of the silicone gaskets and see how that goes.

How about the gunk between the head and the barrel, is that due to some of the surface imperfections that some of you have mentioned and needing to seal the push rods.

On a semi related note, would any of these leaks have anything to do with the fact that my oil is nasty looking after only ~700 miles? I'm thinking this may is more due to blow by through the rings, thinking I may be due for a new top end pretty soon. Far as I know the bike hasn't ever had the top end down, it's got 40,000 miles. Any thoughts on this?
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Re: Help me fix the leaks in the head area!

Postby hobot » Sun Jan 22, 2012 10:17 pm

Nortons are rubber like engine near red line so entirely possible head clamp force lost along the way to blast hot jets past gasket leaving oil and carbon crud. At 40K miles its due for soup to nuts going through time investment before more than just oil leak and wear item replacement involved. Even if ya get it oil tight for a while its usually only for a while till weeps and mist show up again. The bent end wrench sure makes doing this easier on the doer in a few places. Its possible gas jets have cut channels from bore to push rod tunnels which will blacken oil faster than desired.
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Re: Help me fix the leaks in the head area!

Postby Matt Spencer » Sun Jan 22, 2012 10:42 pm

Looks pretty normal , for hard / determined use . But , at 40.000 rings'd do no harm.Leaveing it logner and the clearances increasing , would mean more expense ,IF you can just ' get away ' with that there now , plus light valve grind .

A Comp. test , or better , Blow Down ( pressurise Cylinders ) test would tell you a few things first .

Spotleesly clean , No Burrs , Daggs , or Raised Welts. As In All Mateing surfaces LAPPED FLAT , is Std Practise
if you dont mind it not haveing oil about .Seeing theres a bit of rust there , Its just self preservation takeing hold .

Lapping flat on plate glass with medium fine lapping paste , meticulously removed , and get NONE in the valve/guide
area , so clean 3 - 4 times even on a light valve lapping . Aneal ANY copper gaskets / washers . Lap cam followers FLAT .

One has to be carefull one does not end up with the whole motorcycle dismantled and a two year full overhaul ,
so may pay to prepare & plan a quick top end freshen , and not get distracted . Exploratory Surgerey .
Plenty of Old T shirts / Cotton Rags . KEEP all the dust / grit OUT . Old newspapers on the deck to discard repeatedly
as you go ( into bin bag ) so as the grot isnt used for matrimonial manipulations .

If shes briefed aforehand , two or three uninteruped saessions ( 48 Hrs ) may suffice . :lol: 8) :D
Last edited by Matt Spencer on Sun Jan 22, 2012 10:55 pm, edited 1 time in total.
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Re: Help me fix the leaks in the head area!

Postby dave M » Sun Jan 22, 2012 10:54 pm

Guido is correct about surfacing the covers to make sure that they are flat, I have found many that are bowed from overtightening. The other tip is to trim the gasket near the bottom stud, there can be a lot of excess paper here which acts as a reservoir trapping oil behind it which will eventually leak out.
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