Marzocchi Forks Deconstructed

Buzzsaw

Retro Guru
Due to lots of idle time on my hands recently and a few used Marzocchi forks in the shed with leaky oil seals or other issues I decided to disassemble them and see how they tick and hopefully further on replace all the seals along with fresh oil and get them operational again. Not the best pics but here’s what I found....

Earliest pair was the air oil 1991 PF1 fork which to be the most difficult to take apart as the air valve plug stem broke whilst using the correct tool to remove them plus their idea of having a cir clip ring holding the oil seal on top of the slider was fine but they have another cir clip directly under the oil seal which secures the stanchions to the slider. It’s impossible to remove and the only way is to mangle the oil seal with a picker tool or a small screwdriver while trying to be very careful not to damage the sliders and stanchions! Think they didn’t think too much about aftermarket servicing back then.
Next was the 1998 Z5 Bombers which were by far the easiest to take apart with a more basic air/oil internals for damping compared to their higher end Z1/Z2 models.
The 2002 Super T Pro DH dual crown forks were most sophisticated of this lot with a spring damper assembly with rebound/ preload adjustment. It also had the removable M Arch setup that Marzocchi used on their forks around this period. It was also the reason why these got retired because fork oil had spewed out from join on the slider on ride years ago covering my foot and leg in oil plus rendering my brakes useless!
Finally the last fork was the more basic 2006 Dirt Jam Pro model with one side relying on an air/oil damping and the other side being a basic spring damper with lots of grease! Only bedbug on these is the inset bolt on bottom of the air/oil slider side requires a very thin wall long 12mm socket. There was a special sized Marzocchi tool available for this back in the day but of course impossible to get nowadays so resorted to getting a cheapie 12mm socket and filing and grinding the end until it fitted into the slider insert onto the bolt.
It’s been an interesting exercise learning how to get into these and learning how they work. Now all I need now is to source replacement oil/dust seals for all these and a few more tools and hopefully bring these back to life.

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Well, nice work, cool pictures! The PF1 crown is missing?
I think I can help you with all : seals, tools, manuals, spares.

Just drop me a note.
 
Thanks KraeMit- I forgot to include the PF1 crown in the picture as I had parts everywhere! I’ve been looking at your website and working out my shopping list so expect a message soon. Good that you have the 30mm seals available now as they’re hard to find!
 
Interesting to see the 'cheese grater' bushings in the Z5 - I think that is a 1999 Z5, I don't think they were available in 1998. I've just picked up a set so will be interesting to see if mine are the same internally.
 
I brought these brand new from my local bike store in New Zealand back in the late 90s but can’t remember exactly what year as the old memory is getting hazy nowadays! Production date 98 is stamped on the lowers though. Very simple fork but works well even if it’s at lower end of Marzocchi models at the time. Think the Z5 internals should be the same with air/oil even when they introduced the M Arch and ditched the bolted brace in the early 2000 Z5s.
 
So I just picked up a 2000-model Z5 Flylight Bomber fork in the 100mm travel variety to try on my early-2000s Cr-Mo hardtail to see if I'll like the air version better than the coil-sprung 130-mm Bomber that's on it. I'm actually splitting both forks and switching them around from the crowns down as the frame uses a 1" steerer which I custom-made to use in the older Bomber crown with its clamp-in steerer while the Flylight has a permanently pressed-in steerer.

Anyway once the crown was removed from the Flylight I noticed the left stanchion moves in and out of its lower properly, while the right one feels nice and smooth but appears to have zero damping action on both compression or rebound. Not sure if this is a case of the oil having leaked our (no signs of leaks anywhere on this fork), or something funky going on with the valving, valve issue I can deal with by upping the viscosity of the the oil in the working left leg but no oil is a concerned cause those 30mm bushings seem to have disappeared into oblivion as repair parts. I'm looking at the pictures posted in this thread, and comparing them to my fork it looks like to check oil I need to purge the air first, then gently tap the big aluminum caps/plugs in the top of the stanchions down a notch, then pry the snap rings out, then somehow pull the aluminum caps/plugs back up and out of the stanchions? That sound about right? Also what's the best way to pull the caps/plugs out, adding pressure in the stanchions will likely pop them off but I'm expecting it will be more explosive affairs than ideal for safety? Thanks for any suggestions and/or advice, I used to play with the 2003-up Bombers years ago but this beast is new to me and being nigh-impossible to find in good shape I don't wanna do something stupid end damage it 😂
 
If it is push in, pull out and not screw in.
Then yep, pump it up and it may come out. But use a hose type pump bit screw on to the valve (of the old style) and just pull and wiggle on that.
 
Kk, I'll have to soak up the caps/plugs with some penetrant as they seem to have quite a bit of corrosion going on, then I'll switch my pump hose to the threaded end as you suggested to keep things from taking flight.
 
Rob I bought a recreated Marzocchi valve pulling tool as pictured from Dr Marzocchi.de whose also a retro member here. You could possibly drum up something yourself if you’re handy in the workshop. It’s an essential if you’re working on the old Marzocchi air oil forks.
 

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