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Twin chamber fork - internal leak?

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91197BA5-2795-4CC2-A230-634CF579960C.jpeg.04ca37a6d098309ce4ee74b43898fd33.jpegHey everybody, 

 the fork in question is a marzocchi 50mm. As far as I can tell it is an FbF aftermarket and looks similar to the shiver from that era with some differences according to parts views that I’ve found.

these forks were leaking and had no rebound damping. Took theme apart and added new seals. The inner chambers had pretty much no oil in them. When bleeding the inner chamber the oil is being pushed out around the damping rod when extending it and oozing out of the holes. Hopefully some pictures will explain it better, but the tube at the very bottom has two flats where I would assume you use a wrench to remove it but there’s no other place to hold the tube unless I clamped it in a vice? I can shine a light in there and see what looks like a green Teflon ring. 

Is the problem actually the oil leaking past that ring? Or, is supposed to be pushed out those small holes and then sucked back into the chamber? 

I put one leg together and followed the bleed procedure for bladder forks and that leg seems to be working. I just don’t know if I’m going to end up with all the oil in the outer chamber again, only to be pushed past the fork leg seals.

sorry for the long, poorly written post. It’s the best I could do with the I.Q. I have to work with.

thanks8F77E857-BDD4-48EB-AAB7-7F2636B8E4F6.jpeg.8c4399c0a90ae715b705b87fb65cc942.jpeg

Edited by Cleavon
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You need to separate the cartridge outer I think. You use a tool that clamps around the body to hold it, like a shock shaft holder, basically a lump of ally with a hole in it sliced in half, then you can see if there's a seal at the bottom to seal the shaft. I'd hazard a guess there is, otherwise there would be no need for the bladder.

When I compress my cartridges (later model, 09) the bladder inflates. No oil escapes anywhere.

The later shivers look similar, except that short bit with the holes in it. Yours do look to have the same terrible pistons.

The tool is kinda like this, easy enough to make if you can't get one. Maybe try racetech or someone.

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I went ahead and did the other fork leg. It leaked to, but not as much as the other one. 

Finding parts is going to be a problem it looks like. I guess I’ll start trying suspension tuners to see if they stock these parts, or email feracci and see what they say. Maybe they have a manual written in Italian that they could send me.

What’s terrible about the pistons?

have you had to replace any of the internal parts on your forks?

 

thanks

 

Edited by Cleavon

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15 hours ago, Cleavon said:

I went ahead and did the other fork leg. It leaked to, but not as much as the other one. 

Finding parts is going to be a problem it looks like. I guess I’ll start trying suspension tuners to see if they stock these parts, or email feracci and see what they say. Maybe they have a manual written in Italian that they could send me.

What’s terrible about the pistons?

have you had to replace any of the internal parts on your forks?

 

thanks

 

If they are the same, the pistons have very small compression holes which have a sharp turn in them, which is the enemy of good flow. Basically it makes 'em harsh over sharp bumps. Same on the rebound, 'cept they are the rebound holes, so you can get away with them, though there may be some improvement to be had there too.

Replaced the compression pistons with racetech (work better, not worn or anything) and done the usual bushings and leg seals. Everything else seems ok apart from a lower leg is showing a bit of wear, though not through the chrome yet. Bikes done just over 200 hours.

Once you get the seals out, try your local hydraulics shop, or, we have seal specialist shops here, I'm guessing you would have the same?

Edited by DEATH_INC.

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Thanks for the tips. Total control suspension is in the next town over. I’m going to give them a call and see what they say. Maybe they’ll have an easier time finding parts than I am.

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