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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: foliver on June 03, 2022, 05:27:50 PM

Title: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 03, 2022, 05:27:50 PM
Hello all.

I've checked and adjusted the valves clearances 3 month ago ( in summer) , and i rode 700 km without leaks.
All went ok, new gasket, i adjusted the bolts without torque wrench, i bought one a week later....

Cero leak, but yesterday, after 4 weeks without use it, i've seen an oil leak coming from the valve cover.

The ambient temperature changed from summer ( 25-30 degrees celcius) to winter ones ( 3-9 degree), may be it's related to this?
So now i want to check the torque of the cover bolts with the torque wrench, but i'm not finding the values, someone has this info on hand?

Thanks!

Fabian
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Laitch on June 03, 2022, 07:16:06 PM
The leak is not related to ambient temperature. It's related to how free of oil the gasket mating surfaces were, which type of sealant was used, where the sealant was applied, how the sealant was applied, how much sealant was applied and, of course, how much force was applied to the fasteners. If the cover has been hit when the bike was dropped, a leak could result, too.

In the line reading Rocker cover in the torque specification table of Chapter 11 in the BMW K75 K100 2V Repair Manual that has been downloadable from this section of Motobrick.com (http://www.motobrick.com/index.php?topic=11014.0) for many years, the value that is given unto us is 8 ± 1Nm.
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: frankenduck on June 03, 2022, 09:43:59 PM
It would help us help you if you can tell us where it is leaking oil. Is it leaking at the valve cover bolts or somewhere else?
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Chaos on June 04, 2022, 01:21:39 PM
the bolts holding the valve covers are shouldered, so torque isn't that much of an issue.  What happens is the rubber O rings actually push on the valve cover, when they degrade you may develop a leak.
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: frankenduck on June 04, 2022, 02:18:43 PM
the bolts holding the valve covers are shouldered, so torque isn't that much of an issue.  What happens is the rubber O rings actually push on the valve cover, when they degrade you may develop a leak.

Torque is an issue. If you over-torque the valve cover bolts then the threads can strip in the bearing cap.

8 +/- 1 Nm
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 04, 2022, 03:43:53 PM
Hello all.
Here's a picture, you can see were it drips ( behind the central exaust pipe in the picture) , it's strange cause the big oil "perspiration stain" is new too.
I guess it happens in my last ride?........first time i see the stain.
??
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Laitch on June 04, 2022, 03:54:44 PM
Clean off both stains and keep riding. As long as oil isn't pooling on the floor, no te preocupes. The weather down there seems ideal for riding right now. Check the suspicious area daily as a hobby.  :laughing4-giggles:
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: frankenduck on June 04, 2022, 04:09:56 PM
Did you reuse the old valve cover gaskets? If so they may be old and a little dry which may be what is causing your leak.

You can either replace the gaskets with new ones (11121460622 & 11121460623) or try using a reconditioner on them.

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-ultra-rubber-gasket-sealant-dressing-1-oz/
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Martin on June 04, 2022, 07:00:25 PM
I developed a very small weep on the crankshaft cover. After checking the torque on the bolts which was fine I ordered new grommets and a gasket. New gasket $17.00 Au grommets $1.00 Au each x eight. The old gasket was found to be hard and the grommets hard and compressed, to the point that they hard to be cut off with side cutters.

The old gasket had no sealant and since I have never had this cover off in my 22 years of owning it I believe the cover has been on there since its build. The whole job was easy I dropped the still good coolant into a plastic tub for reuse via dropping the bottom hose which was still pliable and pulled off easily using just my fingers top connection was the same. The alloy where the hoses go was factory fresh no signs of corrosion. I used a smear of silicone grease to push the new grommets over the bolts. I also had to use a smear of Threebond sealant to keep the gasket in place on assembly. Cooling system had to be cycled and burped a few times to remove air pockets.
Regards Martin.

* cover grommets.png (50.74 kB . 768x576 - viewed 353 times)
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 04, 2022, 10:03:03 PM
Clean off both stains and keep riding. As long as oil isn't pooling on the floor, no te preocupes. The weather down there seems ideal for riding right now. Check the suspicious area daily as a hobby.  :laughing4-giggles:

jajjaja, hi Laitch, it's pooling on the floor a bit.....but the strange thing is that is was suddently...
I'll clean, tight the bolts to the specify torque and see...
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 04, 2022, 10:05:12 PM
Did you reuse the old valve cover gaskets? If so they may be old and a little dry which may be what is causing your leak.

You can either replace the gaskets with new ones (11121460622 & 11121460623) or try using a reconditioner on them.

https://www.permatex.com/products/gasketing/gasket-sealants/permatex-ultra-rubber-gasket-sealant-dressing-1-oz/

hi Frankenduck, i used another gasket kit that the previous owner gives me as a bkup when i bought the bike.
It was not sealed in a plastic bag, but both gaskets seemed new...

good tip the permatex!
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 04, 2022, 10:08:41 PM
I developed a very small weep on the crankshaft cover. After checking the torque on the bolts which was fine I ordered new grommets and a gasket. New gasket $17.00 Au grommets $1.00 Au each x eight. The old gasket was found to be hard and the grommets hard and compressed, to the point that they hard to be cut off with side cutters.

The old gasket had no sealant and since I have never had this cover off in my 22 years of owning it I believe the cover has been on there since its build. The whole job was easy I dropped the still good coolant into a plastic tub for reuse via dropping the bottom hose which was still pliable and pulled off easily using just my fingers top connection was the same. The alloy where the hoses go was factory fresh no signs of corrosion. I used a smear of silicone grease to push the new grommets over the bolts. I also had to use a smear of Threebond sealant to keep the gasket in place on assembly. Cooling system had to be cycled and burped a few times to remove air pockets.
Regards Martin.

* cover grommets.png (50.74 kB . 768x576 - viewed 353 times)

Txs Martin for your answer.
The gasket i used seemed new ( the previous owner give it to me as a spare), but the grommets are original, i bet.
If after tighten the bolts, it stays dripping, new gasket, grommets, and permatex sealant are the way i'll go....
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Martin on June 04, 2022, 10:38:14 PM
You only need a smear of sealant in a few places to keep the gasket in place while installing the less the better. You should not need to run a bead of sealant at anytime. Overuse of sealant can lead to problems with the sealant oozing out under pressure. The sealant can then break off blocking filter screens and oil galleries.
Regards Martin.
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: Scott_ on June 05, 2022, 07:48:28 AM
You will need to use some sealant at the joint(x2, ie top and bottom) where the Cam chain cover, Valve cover, and cyl head meet. This area won't seal without it and will leak even with new gaskets and grommets.
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: stokester on June 05, 2022, 07:20:13 PM
You will need to use some sealant at the joint(x2, ie top and bottom) where the Cam chain cover, Valve cover, and cyl head meet. This area won't seal without it and will leak even with new gaskets and grommets.
112350
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 05, 2022, 09:33:06 PM
You will need to use some sealant at the joint(x2, ie top and bottom) where the Cam chain cover, Valve cover, and cyl head meet. This area won't seal without it and will leak even with new gaskets and grommets.

Hi Scott, yes i've used sealant there folowing Chris Harris video, may be it was not enough?....
Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: foliver on June 05, 2022, 09:35:14 PM
I've done the valves work without oil in the bike, now that is working ( with oil) , can i take off the valve cover without draining the oil of the bike?

Title: Re: Leak after 500km of valve clearance adjustment, torque cover values?
Post by: frankenduck on June 05, 2022, 10:19:46 PM
I've done the valves work without oil in the bike, now that is working ( with oil) , can i take off the valve cover without draining the oil of the bike?

Some oil will drip out when you take the valve cover off so have a container underneath. It's not much though. Draining the oil won't matter.