Valve cover leaks...how long for gasket glue to take hold?

[r65_steve]

After doing some work on my R100 and painting the VC, I'm getting a leak. When I bought it a month ago it didn't leak. I did a valve adjustment and tested it. Leaked considerably. Next, I had the heads off for pushrod seals so it's all been apart. I measured a small gap when I put the VC on with no gasket. I reinstalled last night and test fired the bike (didn't ride it) for a few minutes. I cleaned them really well and added a little #2 seal. I added to the head side (glue side). Which might have been an error.

In reading I hear that the head/glue/printed side is supposed to fuse itself to the head after some time. Also that maybe some oil should be applied. (It's self oiling in my case!)

Am I just impatient? Should it take more time than 5 minutes of running in the garage? I'm betting there's a little warpage of the head (esp on the left).

I'm not above adding a second gasket (someone did this for my old bike). In that case do you put sealent between the gaskets? I'm not.looking to go to the silicone version yet.

Thoughts?

 

[20774]

I think it does take some time...not just 5 minutes running in the driveway. As with anything, it's going to take time to bed in. BTW...one of the valve covers on my R100/7 doesn't stick to the heads at all...can't really remember when it did. When I take the covers off the check valves, it just comes off as I gently pull away the cover. I don't think it's a matter of sticking to the head as the gasket needs to fit flat on both surfaces.

As you're aware, there's really no oil pressure inside the valve cover area, so if it's leaking then you have a reasonable size opening. The outside two nuts and the center acorn nut holds things on. Where is the leaking originating? Is the center nut tight enough? Don't go too tight as it will pull threads out.

Didn't we go through some issues with heads and flatness on your previous thread "Pulling the motor to fix this?"?

 

[r65_steve]

I think it does take some time...not just 5 minutes running in the driveway. As with anything, it's going to take time to bed in. BTW...one of the valve covers on my R100/7 doesn't stick to the heads at all...can't really remember when it did. When I take the covers off the check valves, it just comes off as I gently pull away the cover. I don't think it's a matter of sticking to the head as the gasket needs to fit flat on both surfaces.

As you're aware, there's really no oil pressure inside the valve cover area, so if it's leaking then you have a reasonable size opening. The outside two nuts and the center acorn nut holds things on. Where is the leaking originating? Is the center nut tight enough? Don't go too tight as it will pull threads out.

Didn't we go through some issues with heads and flatness on your previous thread "Pulling the motor to fix this?"?

Yeah. We did, that's why I mentioned measuring the gap with a feeler. I wrote it down....somewhere....(lemme look)...edit: must have been purged in the garage clean up, not high numbers (at least I don't think so).

I started a new thread since I figured that one had gone a few different directions.

I do suspect the left head has a little warpage...but not in the checkbook to mill that just yet (or maybe never?).

This is not a geyser leak. Just "marking it's territory" when off. I ran it, shut it off and let it sit overnight over some cardboard. Left a few drops. Right, a slower rate.

Center nut on the right side....I found that the stud was loose. I tightened it in and it was too short. I took it out and looked at it. It's a little bent. (Which explains why it was harder to get the VC on easily).

 

[robsryder]

Silicone valve cover gaskets are available for airheads. If these are installed per the instructions one will not get a leak. I have used these in my airheads for over 25 years.

One use to be able to source these from Rocky Point Cycle, but I now see several providers at various price points. Links follow -

http://www.rockypointcycle.com/c-bmw10_lifetime_silicone_gaskets.html

https://realgaskets.com/product-category/motorcycle/bmw/page/2/

https://www.amazon.com/Silicone-Gasket-Compatible-Airhead-Motorcycles-11/dp/B07D4N2C13

https://www.euromotoelectrics.com/product-p/vc-gasket426.htm

https://www.ebay.com/i/253774770260...80977766998737&abcId=9300372&merchantid=51291

 

[stevenrankin]

center stud

There is another possibility here.

Are you sure it is the valve cover gasket leaking? in your last thread Steve you mentioned the center nut stud being a bit short and "bent". One thing I have seen some airhead owners do is strip out the threads or pull out the center stud threads in the head by over tightening. This in itself will cause a leak for some reason, oil will leak out of the stripped threads.

The fix is to drill and helicoil the threads, for the most part this will work fine. the problem arises when the old threads are not drilled out straight or helicoiled properly. The leak will continue.

I would get rid of the bent stud, make sure the threads are proper and things are straight it might be possible the bent stud is preventing the cover from properly seating on the head.

The newest version of valve cover gaskets BMW is selling seem to be "harder" than from those of the past and as such, they drip or seep a bit. I found on my RT, a quick light coat of gasket adhesive stopped the seep. There is no need to go crazy with sealers in fact, I would be Leary of some of the sealers being applied too heavily and migrating into the oil passages for the valves.

As mentioned, silicone gaskets are also available. St.

 

[r65_steve]

It's possible that it's leaking from the center stud. But I think unlikely. Of course none of this happens when it's running, just sitting, so I figure the oil isn't going uphill to the stud to find its way out. Probbaly just dribbling out from the low points. Not sure how much oil is in there at any point anyhow.

 

[20774]

Possibly that the clearances changes when hot and thus no leaks. I don't think the oil is going uphill, but rather finding the lower gap because the center stud isn't as secure as it should be.

 

[PAS]

I install the NEW gaskets to solvent clean surfaces with nothing on the gaskets. Then take it for a ride long enough to get it up to temperature (225) to get the gaskets to seal when first installed. After wards they are always installed to solvent clean surfaces when removed.

 

[jad01]

I'm not.looking to go to the silicone version yet. Thoughts?

Unless you are willing to do the work to get the surfaces to mate correctly as suggested by Anton and others in the prior thread, it's time to try them. You'll like them.

 

[nickrides]

Silicone gaskets on Amazon for 12 bucks.
What are you waiting for?
Thats a cheap fix
Nick
1978 R-80

 

[r65_steve]

Silicone gaskets on Amazon for 12 bucks.
What are you waiting for?
Thats a cheap fix
Nick
1978 R-80

Can I still park near the Airhead tent at the rallies?

 

[lkchris]

Silicone valve cover gaskets are most useful when the surfaces have been damaged. Remember, some prior owner may have attempted prying before he discovered the little 10 mm nuts also holding the valve cover on. With unmolested surfaces, the original gaskets work fine.

Then again, my experience was silicone gaskets were nearly mandatory for the oil pan gasket. Basically, the OE gasket leaks.

On the other hand, keep silicone gaskets away from gasoline ... they are a disaster with carbs.

 

[lkchris]

Can I still park near the Airhead tent at the rallies?

Only if you don't put it on the centerstand

 

[ccolwell]

While I agree with the silicone seal recommendation, if you are determined to find the source of the leak use Arid Xtra Dry. Or any spray deordorant with a high aluminum oxide formula. Clean the surfaces with solvent, spray the area, run the engine and then let sit. You'll be able to see the trail of the oil in the white powder covering. One of the many things learned from 20th C. British bikes. Sigh.

 

[r65_steve]

Only if you don't put it on the centerstand

ha!

I just bought a Brown side stand and installed it last night.

Also installed one of the red silicone gaskets. (other side seems to have stopped leaking.,). One little drop after another illegal and freezing test ride. Another 1/16 turn on the little nuts and seems to be good.

 

[r65_steve]

While I agree with the silicone seal recommendation, if you are determined to find the source of the leak use Arid Xtra Dry. Or any spray deordorant with a high aluminum oxide formula. Clean the surfaces with solvent, spray the area, run the engine and then let sit. You'll be able to see the trail of the oil in the white powder covering. One of the many things learned from 20th C. British bikes. Sigh.

When I was wiping it down to put on the silicone gasket, I could see where some ape gouged up the top right corner (by the carb). I'll only worry about that if I head for the loop-de-loop.

 

[cycleman2]

Valve cover gaskets should be put on dry. You can put a light coating of oil on the head side if you really want to, but it is not required. If you have gouges and other issues with the surface of the head or the cover that is not the fault of the gasket.

 

[pvanbavel]

Silicone valve cover gaskets are available for airheads. If these are installed per the instructions one will not get a leak. I have used these in my airheads for over 25 years.

One use to be able to source these from Rocky Point Cycle, but I now see several providers at various price points. Links follow -

http://www.rockypointcycle.com/c-bmw10_lifetime_silicone_gaskets.html

https://realgaskets.com/product-category/motorcycle/bmw/page/2/

https://www.amazon.com/Silicone-Gasket-Compatible-Airhead-Motorcycles-11/dp/B07D4N2C13

https://www.euromotoelectrics.com/product-p/vc-gasket426.htm

https://www.ebay.com/i/253774770260...80977766998737&abcId=9300372&merchantid=51291

Just installed silicone gaskets from RealGaskets got no instructions so installed dry. went for a test drive-- oil gushing out , probably lost 3/4 qt. Looks like the gasket slipped out of position on the bottom side, my error, or an overpressure blew it out. other side is leaking but not as bad. I'm thinking that a little thin coat of silicone sealer on the cover side would hold it in place.

 

[20774]

Welcome to the forum! There's no real pressure inside the valve area...oil is just being splashed around and it drains back into the sump. What I've heard is that the valve cover can't be squeezed too much or it will create gaps. I suppose a sealant could help, but don't over tighten the valve cover.

 

[52184]

Just installed silicone gaskets from RealGaskets got no instructions so installed dry. went for a test drive-- oil gushing out , probably lost 3/4 qt. Looks like the gasket slipped out of position on the bottom side, my error, or an overpressure blew it out. other side is leaking but not as bad. I'm thinking that a little thin coat of silicone sealer on the cover side would hold it in place.

The silicone gaskets have been problematic as they tend to squish out of place as the valve cover is tightened. Adding any kind of sealant to them adds an additional problem, as there isn't much of anything that will stick to the silicone and you run the risk of having sealant flake off, go through the oil system, and plug the very small oil passages that feed the valve train and crankshaft. The rubber gaskets used on the oilheads, camheads, and water boxers are rubber but with a metal core that retains their shape.

If your heads or covers have slight scratches or scars you can resurface the covers by removing the studs and true the covers using sandpaper adhered to a surface plate, using a figure-8 motion on the covers. Resurfacing the mating surface on the heads requires removing the heads.

Personally and FWIW, I find the newer BMW valve cover gaskets to be more prone to leaks. You can always do as I have on my R80ST, and cut your own gaskets from sheet cork material sourced from a local NAPA. I adhered the gaskets to the valve covers and have had the same cork gaskets in use for the last 10 years or so.

Best,
DeVern