valve cover sealing

[John M]

My R80 st is now running ,however I have a small oil drip from my left valve cover. all surfaces were clean and new gaskets were used , I snugged up the 10mm nuts a tad and also the center nut .This made no change,any thoughts i.e. new gaskets ? yamabond ? surfacing ?

Regards John Muir

[Barry]

John,

The valve cover gaskets tend to last just about for ever and don't normally leak even with very low torque on the nuts so I would be checking for warping of the cover or head.  I suppose sealant would fix it but ideally you want it to re-seal easily every time the cover is taken off for valve clearances.

[montmil]

If you're feeling industrious, remove the rocker box, double-nut the threaded studs and remove them. Then utilize a dead flat plate to check "flatness" of the cover's gasket surface. A thin feeler gauge will be helpful in locating an area that needs some BMW "love'.

Focus on the lower area of the cover. Confirm your gaskets are located properly.

If a warp/distortion is located, Wet-or-Dri grits and that flat plate can be used to level the surface. BTW, thick silicone gaskets are available for the Airheads. Some peeps like them.

[Matt Chapter]

Some peeps like them.

So I finally realized why my left cover leaks.  And it's definitely because it's warped.  And it's warped because every time the bike has been dumped, knocked over, or wrecked, it's landed on that valve cover.  Close inspection shows mild flaking on the inside of my valve cover!

The eventual solution will be to replace the cover.  In the meantime, I've doubled the gaskets.. I've always liked the thought of a reusable silicon gasket but never gotten around to ordering them.

[Barry]

When everything is flat and provided it's well stuck to the head, the stock gasket is reusable just about indefinitely. So far I have never contemplated replacing the gasket as a service item. It wouldn't surprise me if it's the one the bike left the factory with. For anyone with old gaskets that don't leak, new ones are not needed every service.

[John M]

Thanks everyone, I think I will try  Monte's suggestion and remove the studs and check for flatness.  Regards John

[georgesgiralt]

I had the same problem. And a tube of "Drei bond" at hand. So As I wanted to ride the bike without getting my feet wet, I put a dab of drei bond on every surfaces. At newt service I had forgotten the sealant and it came off easily but the cover is still sealed.... so kind of a miracle product.
You should give it a try....

[John M]

Thanks George, Worth considering as a easy fix.  Regards John Muir

[Bob_Roller]

I had the cylinder heads on my '81 R65 worked on 15 years ago, valve and seat replacement, due to valve recession .

The shop doing the work, called me and said the head surface that mates to the valve cover was warped and could use machinig to truye it up, didn't have any sealing issues at the time .

They said it was a common problem with airhead cylinder heads .

A rubber gasket will  most likely will cure the problem .

[soliecirc]

I have the same oil drip from left valve cover. i have a few questions. I couldn't find "drei bond" anywhere for sale online. Found their website but nothing for sale. Did run into "threebond", is that the same thing or close enough?

if I do seal off that leak with the bond, will that oil just accumulate inside the valve cover causing a problem, or is that where it should be? Will I need to occasionally take off the valve cover just to empty out the pool of oil in there?

Thanks for any advice in advance.

John, update on what you ended up doing?

[Bob_Roller]

The oil in the valve cover returns to the oil sump by way of the pushrod tubes .

[georgesgiralt]

Motobins had it. I think it is called 3 bond in English instead of German.
Maybe your dealer can get it too. I came across the BMW part number for it but can't find it right now.

[soliecirc]

Thank you for the clarification.
Found it on motobins here: http://www.motobins.co.uk/displayfinal.php?q=Drei+bond&go=GO for $15 us plus ship to US. BMW PART-07 58 9 062 376
Then found the threebond version on amazon http://www.amazon.com/Three-Bond-Liquid-Gasket-Ounces/dp/B0012TUVAW: $12.50

Further searching I found it for $5.35 here http://www.powersportsuperstore.com/Three-Bond-Liquid-Gasket-1194-TB1194-p/4459896.htm?Click=35177

I hope the three bond 1194 is the correct product.

[John M]

I resealed my leaking valve cover with a permatex non hardening sealant
as a temporary fix. I will probably go with the silicone gaskets as a permanent solution .     Regards John

[davidpdx]

Real Gaskets makes a silicone gasket that fits our bikes. It sealed up my leaking valve cover nicely.

http://www.realgaskets.com/