First oil change in my Marzocchi forks!

[Jakobi]

What I am saying is that when you insert the piston and comp assembly into the oil, the shape of the piston traps air around the outside edge, which cannot find its way into the center of the piston to be purged past the seal on compression with the cartridge in an upright position.

To test and confirm this belief. Turn the supposidly well bled fork upside down and run it through its stroke. It'll be evident that their is still a significant quantity of air in there.

Prior to this, the fork will appear well bled and return fully as expected with the sound and feel typical of a strong bleed.

In reality though, once assembled its very unlikely that the fork will be inverted and compressed at the same time while in use (riding), so unlikely for this to happen. The air at the top (around the piston) should stay there, added with the transfer of fluid from the outer leg through the cart during use, should self purge further anyway.

[dirtbird]

I did my forks with Jakobi's purge procedure (almost-see below)
First of all, my cartridges had excess oil as I purged them before opening and a significant amount got out.
This explains the harshness I was feeling in the last 2 rides but this time happened quite early (about 15-20 hrs of riding since the last oil change).
The last time I rode (before servicing the forks) I was riding quite slow (even for my mediocre speed) - this was probably a combination of worn tires, cold weather and a fork that was starting to pump up- so this goes along with my theory that the zokes punish you if you are slow .
Also the zip that I had on one fork showed that I had another 6 cm of travel to use.
I rarely bottom out but usually I am close.
Back to the bleeding-purging.... first I put 225ml into the cartridge and after some conventional bleeding (working the cartridge rod), I tried to install the valve. Sorry but not possible.
I had the cartridge sitting on my bench vice (the spring perch on top of the vice) since I didn't wanted to clamp it.
But it required quite a force to engage the threads so I stopped. Not impossible but not ok.Just for testing, In the past I have managed to close the cartridge with the PFP 6 turns but I had an extra pair of hands holding the cartridge.
So it was obvious that the oil quantity was too much. I didn't measured oil level but I used the oil level syringe.
Normally and following the manual's instructions, I use 140mm height. I set it at 130mm (still more than recommended) and was able to close them.
Turned them usd, waited a little and returned them to rsu and waited a little more.
Then tried what Jakobi was suggesting........


Ha......


The thing sneezed like a cat..... turned them upside down and some oil escaped (not much but definitely some) and repeated the procedure 3-4 times.The 2nd time, a very tiny amount of oil came out (almost none) and the following times none. The same happened with the other fork as well (with the same procedure - 225ml then 'correcting' to 130mm). I guess that I am using less oil so this is why after the first air bleeding, I don't notice any more oil coming out.

I rode the bike on Thursday (in a combination of muddy and rocky terrain still with the worn tires) and for sure the forks where back to their best form. I am not sure if it is the new bleeding-purging procedure (as before they had excess oil in the CC) but I am sure that its not wrong.
I have already put some new rubber (Bridgestone X30 fore and aft) and my next ride will be in my favorite route so I will be able to understand better.
Forgot to mentioned, I used 325-330ml on the outer (last time was 350).
Next step is to try harder springs and decrease more oil level (and maybe spring preload.... one at a time, one at a time... )

[Jakobi]

Did you try and cycle the cartridge upside down once you thought it was fully purged?

With the 225ml of fluid, I run the PFP fully open (and my ICS springs do have around 6-7mm play when backed right out). For install I basically follow Glenns method, except use a cartridge clamp thats slightly over size instead of a seal driver. Same logic applies. Push directly down on the cap, and then turn the cartridge body to get the threads to take.

[dirtbird]

If you mean compressing the rod with the cartridge upside down, no.
If you mean repeating the procedure (usd-right side up then compress, then purge) yes I did it several times per fork.
PFP was fully backed out, next time i will try it having the cartridge fully secured on the vise.

[Jakobi]

There will be some variation in resistance depending on how the spring is setup on the PFP too. I've seen at least 3 different lengths while working on these forks (although one was installed by another tuner). For my forks I've found I can install with 225ml, which gives me around 16ml (from memory) to get a couple of purges with.

Compressing the damping rod with the cartridge upside down is the 'test'. If there is air in the system it will be heard as it passes through the midvalve piston. As I've alluded to, I don't really feel its all that important in the grand scheme to have it completely air free like you'd expect in a shock, as its not an entirely closed cartridge. It does cycle fluid from the outers and continues to overfill and purge during use.