Suntour Epicon X2 lock out issues -> hydraulic cartridge leak

BrunoC · Jun 23, 2013

Hello,

My bike has a Suntour Epicon X2 since October 2012 (600 km) which has a Remote Lock Out.

After a race where I didn't use the lock out, I discovered it was not working anymore.

I have eliminated a remote and cable cause because I tried to turn the mechanism on the fork itself, with the white plastic part (see my pic). This is turning endlessly on both sides, with no effect. This plastic part is not broken and it is well turning the metallic part of the cartridge in which it is inserted.

I have opened my fork by removing the lower tubes. I didn't see clearly a oil leak (you must or have to know that this suntour has a sealed hydraulic cartridge). I didn't open the cartridge because I have never done it (and that's not good for warranty).

There is also a strange sound when actioning the fork (like a "click"), sound that appeared a bit before this problem.

I don't have any other Suntour Epicon to compare the lock out mechanism (if it turns endlessly or not, for instance).

Conclusion: I am lost and upset.:sad: I found a lot about RS or Fox issues, but not Suntour.

BrunoC · Jun 24, 2013

I have a good and bad news.

The good one is that I have identified the cause.
I have a leak on the hydraulic cartridge. One seal has developped hernia and is leaking oil and bubbles.

The bad one is that I don't know how to change the seal. Suntour is not yet answering. I don't know any Suntour retailers around.

A bit disappointed about Epicon durability...

ericgautier · Jun 24, 2013

Please keep us updated.

BrunoC · Jun 24, 2013

ericgautier said:
Please keep us updated.

I will :thumbsup:

Because this time, I have a good news and no bad one

I was afraid to open the cartridge where there is the leak, but I realised I could do it without tools: the thing was loosened! And the seal has been pushed outside the "screw area": I mean, when it is well screwed, the seal is not visible.

So, I will need to refill the oil of the cartridge, to tighten it up well (I need the proper tools) and it should be like before.

Cartridge loosened -> oil leak -> lock out issue (and no shock absorber, the fork was bouncing). It should be the story.

speedneeder · Jun 25, 2013

Good luck.

rukomasa · Sep 1, 2014

I had exactly same problem today. EPICON X1 29 RL-RC. Suddenly fork start moving while climb on the road. White gear never stopped if I rotated.

Removed the damper cartridge but no luck, there looked no loose or no leaks. However, I tightened the same place for just in case, it moved only a few, maybe 1 degree or 2, then, fixed! Thanks a lot for sharing above information.

Seemed like the gear rotates entire piston which should not rotate. I noticed that moving the shaft was giving pressure to the piston and gear works. So I tightened. fix.
Maybe pressure in the cartridge some how stops the piston from rotating. Not sure but maybe same problem one day if the pressure is lost during years of use.

Forcemajeure · Apr 12, 2015

the hydraulic cartridge they can be repaired and opened up right?

rukomasa · Apr 14, 2015

Never contact to suntour. There was a sticker showing "void if removed" so they does not want us to open the cartridge.

GuitsBoy · Apr 20, 2015

Yeah, any time you open the cartridge, you void the warranty. But if the fork is old, or if it was purchased from ebay / ali express or other asian market vendors, you may not have a warranty anyway.

One thing I do want to add is that the lockout may not initially function if the fork has been sitting for a while. I thought my lockout bit the dust last year, pulled the cartridge to inspect, reassembled, and it magically started working again. Tuns out it just needed to be cycled a few times to get the oil flowing. Now I notice it happens whenever the bike sits. But the lockout works fine again after a few feet of riding.

FJP · Jul 6, 2016

Hi, I have also a ticking/clicking sound while riding so I want to check my rebound cartridge. I removed the top cap of the manual lockout. Should I remove the locknut with a 27mm spanner to be able to pull the cartridge out from above (after tapping it loose from the bottom)?

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rukomasa · Nov 4, 2016

Hi FJP

I recommend lose the right leg bottom first. Before remove the nut or bolt, beat gently by plastic hammer. Then lose the 27mm on top.
You can pull out entire cartridge.

Today i got the same problem again suddenly. I checked the damper cartridge at home but no lose this time.

Brought it to two shops and asked to change the oil but both of them refused. I told them i pay before and dont complain even if no improvement. Ok, good bye LBS.

Finally, i lose the cartridge, 1 turn or two at the middle. The got some leak of course. Then tighten it again. Wow now it is fixed.

I cant see why the white gear to lock lost the grip, and cant see why tightening always recover the lock out gear. Anyway it is good not to spend another 300USD for a new fork.

Sent from my iPhone using Tapatalk

FJP · Mar 12, 2017

rukomasa said:
Hi FJP

I recommend lose the right leg bottom first. Before remove the nut or bolt, beat gently by plastic hammer. Then lose the 27mm on top.
You can pull out entire cartridge.

Today i got the same problem again suddenly. I checked the damper cartridge at home but no lose this time.

Brought it to two shops and asked to change the oil but both of them refused. I told them i pay before and dont complain even if no improvement. Ok, good bye LBS.

Finally, i lose the cartridge, 1 turn or two at the middle. The got some leak of course. Then tighten it again. Wow now it is fixed.

I cant see why the white gear to lock lost the grip, and cant see why tightening always recover the lock out gear. Anyway it is good not to spend another 300USD for a new fork.

Sent from my iPhone using Tapatalk

Thanks for the reply. Long time went by but now I decided to go for a DIY service on my fork. I took the fork apart for a thorough cleaning. Then I want to change travel to 120m, refresh the oil in the damper cartridge with 5wt fork oil. And relube/regrease everything a again, and put some 10wt or 15wt in the lower legs and some 80w gear oil into the air chamber.

I have a question about the grease to use on the travel adjustment spring and air piston.

I am thinking about a red rubber grease like "Pentrite red rubber grease" or a calcium based grease like "Motorex universal grease 176 gp"

What type of grease should I get?

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Suntour Epicon X2 lock out issues -> hydraulic cartridge leak

BrunoC

BrunoC

ericgautier

BrunoC

speedneeder

rukomasa

Forcemajeure

rukomasa

GuitsBoy

FJP

rukomasa

FJP

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