Marzocchi slider bolt

triumphguy

triumphguy

Junior member
Good morning,
The fork oil I have been putting into the Marzocchis on my 1978 1200 Jota America is slowly escaping past the bolt at the bottom of the slider.  I tried re-annealing the copper washer but it made only a slight improvement.  I can't get the bolt *tight* because the damper rod turns and preloading it with the fork spring still won't stop it.  Is there something I could jam (shudder) down the fork tube to keep the damper rod immobile so I can tighten up the bottom bolt?  Has anyone tried dowty washers instead of the copper ones?

Thanks,
Patrick Cherry
Ojai, CA  USA
 
Hi Patrick,

Try doing it up with a rattle gun on its' lowest torque setting, always worked for me!  Good for un-doing as well.

Dowty washers also work well, still got the tightening issue, though.

piet
 
I spent years chasing Hydraulic oil leaks before discovering Loctite 577 thread sealant.
Absolutely pisses all over PTFE tape, Dowty and even Copper Washers for sealing threaded fittings.
Doesn't have to be done up tight.

http://www.loctite.co.uk/cps/rde/xchg/SID-7841F3AD-54CF8FCA/henkel_uke/hs.xsl/fullproduct-list-loctite-4995.htm?iname=Loctite+577&countryCode=uke&BU=industrial&parentredDotUID=productfinder&redDotUID=1000000IY7U
 
+1!

Loctite thread sealant also works well, not only on fork bolts.  But these should be done up tight nevertheless... don't want the damper body rattling around inside the fork tube! ;)

piet
 
Patrick - if you haven't got a rattle gun, with care you can use a ratchet strap to fully compress the fork leg to get the bolt fully tight.  Use a screwdriver blade or similar to stop the strap slipping off the bottom of the leg (and with the hex key driver in situ before you start tightening the strap!)  Protect the fork leg with cloth or an old leather glove to avoid the ratchet lever damaging it.
 
Next time you have the damper rods out, you could grind a hexagon into the top edge of the damper valve housing so you can fit a socket over it. It doesn't bear against the inside of the fork leg or seal against anything, so it doesn't have to be round (thinking Marzo here. I've not seen the inside of a Ceriani)

Cheers,
Cam
 
Dellortoman said:
Next time you have the damper rods out, you could grind a hexagon into the top edge of the damper valve housing so you can fit a socket over it. It doesn't bear against the inside of the fork leg or seal against anything, so it doesn't have to be round (thinking Marzo here. I've not seen the inside of a Ceriani)

Cheers,
Cam
Click to expand...

That's thinking outside of the square, Cam.  :)

bazzee
 
sfcpiet said:
+1!

Loctite thread sealant also works well, not only on fork bolts.  But these should be done up tight nevertheless... don't want the damper body rattling around inside the fork tube! ;)

piet
Click to expand...

The thread sealant also acts as a thread locker, so will not work loose (11 Nm breakaway torque).
Cams idea looks best to get the initial tension if you don't mind dismantling.
 
It's probably not a good idea to put any sealant on the actual thread. If the thread is glued up and you don't have a method to get a positive grip on the damper rod, you could be spinning the damper rod inside the fork leg until you die of old age.

Cheers,
Cam
 
I spent thrity years fucking around trying every method known to mankind until a mechanic told me about the rattle gun. I now own a rattle gun and it's used for one thing and one thing only. Go buy a rattle gun.

Chris
 
Dellortoman said:
Next time you have the damper rods out, you could grind a hexagon into the top edge of the damper valve housing so you can fit a socket over it. It doesn't bear against the inside of the fork leg or seal against anything, so it doesn't have to be round (thinking Marzo here. I've not seen the inside of a Ceriani)
Click to expand...

Cam, Ceriani damper valves are flat on top with a round hole for the oil to slosh through, not really anywhere to do creative grinding. When I used to work on chookchasers a lot they mostly had an extension of the damper rod sticking up above the damper rod with flats on both sides. You just took a bit of copper waterpipe and banged the sides together at one end a bit, and used that tool to hold the damper rod while you loosened the bolt.
Unfortunately, nothing like that on Cerianis. I just need to explain to SWMBO why I have to have a compressor in the garage. I'm still in trouble for having bought a hydraulic bike lift.

Ken
 
Dellortoman said:
It's probably not a good idea to put any sealant on the actual thread. If the thread is glued up and you don't have a method to get a positive grip on the damper rod, you could be spinning the damper rod inside the fork leg until you die of old age.

Cheers,
Cam
Click to expand...

Loctite stays liquid for a few minutes before it sets, so that is the time to tighten.
I use the 577 on my Jota sump plug - not a drip to be seen! Not all that tight either.
 
Patrick, Try a non glue,non impact gun idea.First run a tap through the threads in the damper to clean up any crap that may be in there and a die on the bolt to make sure there aren't any burrs to bind as it is tightened.
On the bottom face of the damper body where it sits on the slider you could use a sharp center punch and raise a pip or two to bite into the fork leg when it is tightened. This worked on a Honda I just assembled.
 
Excellent suggestions all, so I took'em all (almost)
I eschewed the copper washers in favor of dowty washers.
I cleaned the threads.
I rigged up a fixture to fully compress the spring using a ratchet strap.
I used a thread sealant.
I tightened them up with my 'middle' rattle gun (I have 3).
So far (60 hours) no leaks...

Once again, thanks to all.
Patrick Cherry
Ojai, CA  USA
 
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