water ballast valve LS6c/LS7

[Tibor Arpas]

Hi,

I'm struggling to elimitate water ballast leaks in a LS-7 after it has not been used for years. The wing valves seem to be one of the challenges. They leak regardless of the force applied to the actuator.

I assume the valves are the same as in LS6c (and not available as spare part any more)
Here is a picture of the valve https://goo.gl/photos/CvYt9SPy9efS8QR56

I couldn't find a way to dissasemble the valve to be able to inspect or replace the gasket. From one angle it's kind of possible to see into the valve, and it looks like it's just a metal ring pressing against plastic pipe with a tiny overlap. So no gasket?

Any idea how to fix the leak? Advice would be greatly appreciated, thanks!

Tibor

[Vernon Brown]

At 07:23 11 August 2015, Tibor Arpas wrote:
>Hi,
>
>I'm struggling to elimitate water ballast leaks in a LS-7 after it has
not

>=

>been used for years. The wing valves seem to be one of the challenges.

>They=

> leak regardless of the force applied to the actuator.
>
>I assume the valves are the same as in LS6c (and not available as spare

>par=

>t any more)
>Here is a picture of the valve https://goo.gl/photos/CvYt9SPy9efS8QR56
>
>I couldn't find a way to dissasemble the valve to be able to inspect or

>rep=

>lace the gasket. From one angle it's kind of possible to see into the

>valve=

>, and it looks like it's just a metal ring pressing against plastic pipe

>wi=

>th a tiny overlap. So no gasket?
>
>Any idea how to fix the leak? Advice would be greatly appreciated,
thanks!
>
>Tibor
>
>

No it cant be disassembled, Its been chemically welded , it would have to
be cut open.

[JJ Sinclair]

Thick lube like vasalene libarely applied is the only answer I know. Believe the valve is like the LS-3a which uses a plastic ball on a stick. Goop lube on the ball as the rod is slowly turned. Do this before every flight where water is carried. May be able to reach the ball hith your finger, if not use a swab on a bent wire (coat hanger). Make sure the dump lever on the root rib (fuselage side) has a enough slop so that it isn't shoving on the rod before you want it to shove on the rod during dump.
Hope this helps,
JJ

[John Bojack J4]

Does it leak outside the plane? I was going to suggest looking at the cable adjustments inside the fuselage. Perhaps the lever that activates the valve is poorly adjusted? J4

[nov...@gmail.com]

I have no experience with LS valves but I can say that toilet wax (the ring that seals the tiolet to the floor) is way better than vasalene on S-H valves.

[Tibor Arpas]

Thanks for your suggestions. I was afraid there were no very good options. Yes, it also leaks when tested out of the glider.

Did anybody actually cut the valve open (and what did they do there?) or manufacture a replacement?

It's probably not the same system as LS3.

What do you guys think will happen if I let submerged in vinegar/water solution for an hour?

I have also Molykote 111 which is suposed to be better then vaseline, but I might investigate the wax solution more.

Tibor

[JJ Sinclair]

Mineral deposits in the valve seal may be causing the leak, you might try soaking the valve in Lime-a-Way or SLR, then flush out under pressure. Try to figure out a way to lube the seat when valve is inside the wing.
JJ

[Papa3]

On Thursday, August 13, 2015 at 9:39:20 AM UTC-4, JJ Sinclair wrote:
> Mineral deposits in the valve seal may be causing the leak, you might try soaking the valve in Lime-a-Way or SLR, then flush out under pressure. Try to figure out a way to lube the seat when valve is inside the wing.
> JJ

Yup. I would do everything possible to make sure the ball is able to seat correctly including cleaning as suggested, lubricating the O-Ring with glycerin first followed by wax to help it seat. I helped on two LS6 valve-jobs, and they were solved by the above. The mechanism itself is fairly simple, so the likely culprit is seating of the ball valve.

Erik Mann (P3)