Schemp Hirth water ballast dump valves

The standard method to close the leaking seals is rubbing vasoline over the
valves into the leaking gap. In this way the vasoline works as an additional
sealing. Works great but must be repaeted about every time the tanks are
filled with water.

Karel, NL



"tango4" schreef in bericht
...
The dump valve on my Nimbus 3 are leaking - one leaks about 10 litres
overnight, another 10 litres an minute, the others somewhere in between.
I'm looking for help on how to go about sealing them better.

I will get some new springs manufactured to push the valves closed but I
would appreciate help on how to renew / refurbish or repair the existing
seals themselves.

Tkx
Ian

Um, Ian, what does the manual say about leaving water in overnight ?
I'm not going to add the the numerous responses you'll get about
applying chapstick/vaseline to your lips then kissing the glider...
See ya, Dave

"tango4" wrote in message ...
The dump valve on my Nimbus 3 are leaking - one leaks about 10 litres
overnight, another 10 litres an minute, the others somewhere in between.
I'm looking for help on how to go about sealing them better.

I will get some new springs manufactured to push the valves closed but I
would appreciate help on how to renew / refurbish or repair the existing
seals themselves.

Tkx
Ian

Ian,

As stated below, it is indeed possible to change the dump valve spring,
although I'm not sure how one could actually change the dump valve plug! The
spring can be worked out of and into the torque rod hole in the root rib
after removing the nut, bushing and seal. A new one can be worked into the
hole and onto the shaft and then wound up using a special brass tube with
notches in it that I received with my N3. I've done it once - very fiddly
process and took about an hour of messing around.

It's necessary to "clock" the shaft properly when re-assembling and winding
the spring - very difficult to describe the entire process - you'll just
have to mess with it until you get it. I could send photos of my dump valve
and shaft tool collection. As JJ noted, my N3 also came with external
springs (at the root rib connection) installed that helps increase the dump
valve closing force.

I use Fuelube for the valve lubricant, after carefully sanding the faying
surfaces of the valve and seat to insure as good a fit as possible. No leaks
noted with Fuelube. I carry one US gallon of water in the RH outboard tank
to compensate for left wing heaviness... until I re-finish the LH wing next
year - then they should weigh about the same.

Jim

"tango4" wrote in message
...
The dump valve on my Nimbus 3 are leaking - one leaks about 10 litres
overnight, another 10 litres an minute, the others somewhere in between.
I'm looking for help on how to go about sealing them better.

I will get some new springs manufactured to push the valves closed but I
would appreciate help on how to renew / refurbish or repair the existing
seals themselves.

Tkx
Ian

"tango4" wrote in message ...
The dump valve on my Nimbus 3 are leaking - one leaks about 10 litres
overnight, another 10 litres an minute, the others somewhere in between.
I'm looking for help on how to go about sealing them better.

I will get some new springs manufactured to push the valves closed but I
would appreciate help on how to renew / refurbish or repair the existing
seals themselves.

Tkx
Ian

Ian

I remember from an earlier similar thread that Peter Harvey UK
(Nimbus4) explained how he repaired leaks by using silicone to make a
new seat for the
dump valve. May be you can contact him or put your question on
www.gliderpilot.net

c u Bruno

Hi All

I used up a cheap lip balm on the valve seats today. A quick wipe around
before closing the valves then a fair amount applied to the closed valves.

Not a drip in sight!

Thanks everyone.

Ian

"Bruno Ramseyer" wrote in message
om...
"tango4" wrote in message
...
The dump valve on my Nimbus 3 are leaking - one leaks about 10 litres
overnight, another 10 litres an minute, the others somewhere in
between.
I'm looking for help on how to go about sealing them better.

I will get some new springs manufactured to push the valves closed but I
would appreciate help on how to renew / refurbish or repair the existing
seals themselves.

Tkx
Ian

Ian

I remember from an earlier similar thread that Peter Harvey UK
(Nimbus4) explained how he repaired leaks by using silicone to make a
new seat for the
dump valve. May be you can contact him or put your question on
www.gliderpilot.net

c u Bruno