On my LAK-17a I lubricated the valve seats with chap stick.Â* I cleaned
them each time to avoid dirt build up.

On 10/30/2018 6:53 AM, krasw wrote:
On Monday, October 29, 2018 at 10:50:25 PM UTC+2, wrote:
Per Schempp-Hirth, I am the owner of a Discus CS with NON-Schempp-Hirth water dump seats on the wing dump valves. Per S-H, ALL S-H, including CS's, have aluminum discs for seats. My ship has what appears to be rubber or similar material for seats. Soon, they will be leaking and though I think I have figured out how to replace them, I am open to suggestions from anyone with first-hand knowledge of replacing non-aluminum seats. Big question for that person(s) is where do you get the part? And, what is the serial number of your ship?

Related question: if you own a Discus CS, would you please look at your seats (underside of each wing, near root) and, if you find that yours are NOT aluminum, let me know the serial number so that I can bring S-H that information.

Visible on my seat is a rubber seat in the center of which is a brass hex head with a female 8 mm thread for the pull-down tool. Standard S-H is simply an aluminum disc with and 8 mm female thread.

I am listed on the SSA website and you are welcome to contact me directly there if you prefer.

Thanks for any help.
All old Schempp valves leak sooner or later (and probably new ones, too). If they leak only a little pilots usually grease the seats. Then the grease collects sand particles and soon you have a moderate leak. Then pilots pull the valve with hand tool and voila, you have a huge leak. The seal is done pretty much between gelcoat and aluminium. It does not take engineer to figure out how good seal can be made with that.

Your rubber seat sounds like space age tech, you might want to hold on to those for a long time.

First rule of all maintenance regarding water ballast: if it works, do not touch it. (Second rule: filter the water).

--
Dan, 5J