Schemp Hirth water ballast dump valves

[tango4]

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

[Stewart Kissel]

You are using some sort of wax sealing agent at the
valve? I use Carmex, others use Chapstix...and I am
sure other products work well. Also you are pulling
the valve tight with the rigging tool? Only thing
else I can think of is to work the dump actuating lever
to free up the linkage.



At 06:48 01 September 2004, Tango4 wrote:
>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
>
>
>

[John Sinclair]

Ian,
Your Nimbus 3 has internal springs that have long since
rusted off (part of the problem) and there is no practical
way to replace them because that involves opening up
the wing. I added stronger external springs that apply
more torque to the dump shaft (s) , one on the inboard
and another on the outboard, as I remember. Then I
would goop up the dump valves with chap-stick, insert
the 6mm tool and pull down with a half twist. That
seemed to do the trick. In real hot weather I would
use very heavy wax, the stuff that your toilet bowl
sits on.
JJ

[John Seaborn]

Ian

Take a minute and determine how the valves are leaking. If the H2O is
dripping around the edge of the plug then this is completely normal
and can be fixed easily. Buy a tube of lip balm (Chapstick in USA)
open the valves and put a good coating around inside the wing on the
lip were the metal plug seats in the opening. Then close the valves
with a snap and your leak is no more. Do not use grease as it washes
away and is a mess. If they still drip a little use the red tail pin
removal tool to seat the plugs by screwing it into the bottom of the
plugs and pulling a bit to seat them. After a few treatments you will
be leakless all summer.

If the valves are leaking past the root wing rib into the cockpit area
then it may be a corrosion problem with the water ballast control rod
that drives the valves - and that is a bigger, more expensive problem.

John Seaborn
Ventus 2b
USA



"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

[Roy Bourgeois]

Ian:

Before filling mine I lock open the 4 dump valves and swab the inside of =
the valve orifice with a q-tip dipped in vasoline. Then close, pull with =
the tool & fill.

Observe for any drips. If you see any gently rub some vasoline into the =
rim of the valve (without pressing up too hard).

I've noticed that after I do this a few times - I can skip the first =
step for a few flights.

Roy B.

[PSUSOAR]

The toilet bowl wax idea JJ talks about works great -- but as he states you
have to use the tail rigging tool to pull the plugs down firmly into the seat
(sqeezing the excess wax out of the seat). With properly seated valves (see
below) this makes for zero leakage over the entire day.

I also have a nimbus 3t and had to repair/replace the INTERNAL parts on one of
my dump valves (broken/bent actuating bolt that was badly corroded). To do that
repair the external and internal spring need to be removed, parts replaced and
then the whole assembly rebuilt. Everyone said that rather large holes would
need to be cut into the wings to do this -- NOT TRUE. By removing the pushrod
seal/boot you can gain access to the internal spring & dump valve components
thru the wing root.

I decided to replace all of my internal springs at the time the repair was
being done to the one bad valve. An e-mail to Biggo @ Schempp-Hirth was the
solution to my problems. I ordered all the parts needed from him to replace
the internal /external springs and discussed the repair to be made. In
addition to sending me the ordered parts, he include photos of a nimbus 3 wing
opened up into halves and showing all the internal parts, how the went together
and how to specifically replace the internal springs. I could have kissed him
for those photos showing how to make the repair. He also very kindly sent me a
simple/crudley made tool used to remove / re-install the intenal springs at no
charge. I can't speak highly enough of Biggo @ Schempp-Hirth for how I have
been treated on numerous occasions. Because I was reparing the actual dump
valve mechanism I also needed a long handled open ended wrench (to reach inside
the wing to the parts). I had a local welder add an flat extension to a normal
open ended wrench.

If you need more access to the internals than that (you will not if only
replacing the interanal springs with the factory rigging tool) you can remove
the aluminum dumb valve plug itself by drilling 2 very small holes into the
aluminum plug -- then put safety wire thru those holes (for leverage) and
turned the plug off the bolt. Then you can access the entire mechanism thru 2
locations (wing root push-rod seal and open dump valve hole). After ALL your
repairs are made, use the safety wire to screw the alum plug back on (take the
time to space it at the right height for a good, flat seal --we "shimmed it"
using 2 nuts on the new stainless steel bolt above the plug) and seal the small
holes in the alum plug with silicon. Then use the tool to re-install the new
internal springs, reinstall the wing root boot/seal, reinstall the external
springs and test the system.

My suggestion is to order the parts you need from Biggo and specifically ask
for the zerox copies of those open wing photos. The repair is not hard to do
and can be done in part of a weekend day if you have a shop with saw horses
available. You have to be careful of the rubber boots/bellows on the wing root
seal becasue old ones can be a bit fragile -- but M & H Soaring stocks them if
you accidently rip one. If you need to borrow the special tool Biggo gave me, I
am willing to loan it out -- but you will have to promise to return it to me.

I hope this helps you and good luck.

Steve McLaughlin (PSU)

[Chris OCallaghan]

Ian,

I may not be offering any new information here, but let me suggest the
following. Clean the sealing surfaces, then close and very lightly
seat the valves with your bolt-knob. Before putting in any water, take
a chap stick and apply fenerously around the edges of the seal. While
the wings are filling, work any excess into leak points along the seam
gently with your fingers, being careful not to unseat the valve. I've
had success with this... much more so than applying chap stick,
vaseline, and other sealants to the surfaces before closing. After a
few such applications, you shouldn't need to seat valve, assuming
there is ample tension in the closing mechanism.

[J Larsson]

"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

For me it works excellent to just smear some vaseline between the seat
and the valve. After that I use the schemmp-hirth tailplane mounting
tool to firmly pull the valve against the seat (there is a 6mm
threaded hole in bottom of the valves which I believe is there exactly
for this reason).

Regards
/ Jan Larsson
Mini Nimbus C #121
Sweden

[John Galloway]

I hope I'll never need it but I'll keep a copy of this
posting.

Are there any ways of preventing corrosion in the internal
actuating components - other than keeping the tanks
dry as much as possible?

John Galloway


At 15:48 01 September 2004, Psusoar wrote:
>The toilet bowl wax idea JJ talks about works great
>-- but as he states you
>have to use the tail rigging tool to pull the plugs
>down firmly into the seat
>(sqeezing the excess wax out of the seat). With properly
>seated valves (see
>below) this makes for zero leakage over the entire
>day.
>
>I also have a nimbus 3t and had to repair/replace the
>INTERNAL parts on one of
>my dump valves (broken/bent actuating bolt that was
>badly corroded). To do that
>repair the external and internal spring need to be
>removed, parts replaced and
>then the whole assembly rebuilt. Everyone said that
>rather large holes would
>need to be cut into the wings to do this -- NOT TRUE.
> By removing the pushrod
>seal/boot you can gain access to the internal spring
>& dump valve components
>thru the wing root.
>
>I decided to replace all of my internal springs at
>the time the repair was
>being done to the one bad valve. An e-mail to Biggo
>@ Schempp-Hirth was the
>solution to my problems. I ordered all the parts needed
>from him to replace
>the internal /external springs and discussed the repair
>to be made. In
>addition to sending me the ordered parts, he include
>photos of a nimbus 3 wing
>opened up into halves and showing all the internal
>parts, how the went together
>and how to specifically replace the internal springs.
> I could have kissed him
>for those photos showing how to make the repair. He
>also very kindly sent me a
>simple/crudley made tool used to remove / re-install
>the intenal springs at no
>charge. I can't speak highly enough of Biggo @ Schempp-Hirth
>for how I have
>been treated on numerous occasions. Because I was
>reparing the actual dump
>valve mechanism I also needed a long handled open ended
>wrench (to reach inside
>the wing to the parts). I had a local welder add an
>flat extension to a normal
>open ended wrench.
>
>If you need more access to the internals than that
>(you will not if only
>replacing the interanal springs with the factory rigging
>tool) you can remove
>the aluminum dumb valve plug itself by drilling 2 very
>small holes into the
>aluminum plug -- then put safety wire thru those holes
>(for leverage) and
>turned the plug off the bolt. Then you can access
>the entire mechanism thru 2
>locations (wing root push-rod seal and open dump valve
>hole). After ALL your
>repairs are made, use the safety wire to screw the
>alum plug back on (take the
>time to space it at the right height for a good, flat
>seal --we 'shimmed it'
>using 2 nuts on the new stainless steel bolt above
>the plug) and seal the small
>holes in the alum plug with silicon. Then use the
>tool to re-install the new
>internal springs, reinstall the wing root boot/seal,
>reinstall the external
>springs and test the system.
>
>My suggestion is to order the parts you need from Biggo
>and specifically ask
>for the zerox copies of those open wing photos. The
>repair is not hard to do
>and can be done in part of a weekend day if you have
>a shop with saw horses
>available. You have to be careful of the rubber boots/bellows
>on the wing root
>seal becasue old ones can be a bit fragile -- but M
>& H Soaring stocks them if
>you accidently rip one. If you need to borrow the special
>tool Biggo gave me, I
>am willing to loan it out -- but you will have to promise
>to return it to me.
>
>I hope this helps you and good luck.
>
>Steve McLaughlin (PSU)
>
>
>

[K.P. Termaat]

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
>
>

[K.P. Termaat]

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
>
>

[Dave Nadler YO]

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

[Jim Phoenix]

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
>
>

[Bruno Ramseyer]

"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

[tango4]

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