A fellow boater had a Navtec integral hydraulic backstay adjuster that blew
the top seal.  As many of you know, this is probably the most common
failure for these.  Exposure to UV and the elements deteriorates the rod
wiper at the top of the cylinder and it's downhill from there.  (I
recommend a 1/2 washer on top of the cylinder.)

This list has been down this road many times.  There's always a discussion
whether to take the thing to a local hydraulic shop or let Lew Townsend in
Seattle rebuild it.  For the record, I sent Touche's adjuster to Lew a
couple years ago and am a satisfied Lew client.

So I called Lew and chatted with him about this "orphan" adjuster.  He
asked some critical questions.  Was I going to keep it as a spare?  Was I
going to try to auction it?  He commented that neither option was
particularly economical.  Hmmmm.  Then we talked about snow skiing.  We're
both avid skiers.

After some thought, I tended to agree with Lew.  Including shipping, a
rebuild would be north of $400-500.  An expensive gamble to have it sit on
eBay for weeks like others I've seen.

So I decided to give the rebuild a shot myself.  The Navtec seal kit, IF
you can find one, is about $200.  Philosophically, it's not much more than
a manual hydraulic jack that compresses rather than lifts.  Internet
research turned up a set of rebuild instructions.  See here:

https://www.plaisance-pratique.com/IMG/pdf/navtec_hydraulik_service_manual.pdf

Armed with instructions and a pair of calipers, off I went.  Disassembly of
the cylinder was fairly straightforward.  I found several equivalent seals
at mcmaster.com.  For those who are really interested, parts below are
referenced on Page 8.

Part  Qty   Navtec     Mcmaster  Price
31      2    HJ-2-215   9452K36    $12.08   (Needed 2.  Had to buy 100)
35      1    HI-005       9505K39     $4.83
36      1    HN-002     9403K55      $2.30

Jug of Fram Hydraulic Jack Oil AW32.  $10

Reassembly went well.  I strapped it between two trees in my backyard and
pressured it up.  I noticed the thing was leaking from the pump piston.
Okay, I pulled the pump handle and piston.  The piston rod seal
disintegrated when I removed it.  Turned out this is a generic U seal with
o-ring 1/4x1/2x1/4.  Internet search on the Navtec number turned up
numerous suppliers.  I bought it from Crescent Hydraulics in south Florida.

Part  Qty   Navtec                   Crescent                    Price
39      1    12500250-250B   P125-00,250-250B       $4.05

It's now back between the trees pressured up to 500-700.  Hard to tell
because the gauge lens is very crazed.  But it seems to be holding.  I'll
know for sure in a couple days.

Granted, I did not get into the actual pump assembly and all the check
valves, etc.  The cylinder walls, rods, etc. seemed to be in excellent
condition so no polishing was necessary.

So far I'm in it for less than $50.

I want to replace the pressure gauge.  I can't find a generic one that is
equivalent.  It needs to be a certain shape for the gauge cover to fit it.
It looks like a gauge off a fire extinguisher.  Oh. well.  A challenge for
later.

-- 
Dennis C.
Touche' 35-1 #83
Mandeville, LA
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Thanks for your help.
Stu

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