Dvo diamond D1 bleed issue

[peanut]

Hi all, hoping someone is familiar with the Diamond or bladder bleeds.
I've serviced every fork I've owned but this is the 1st bladder fork I've changed fluids on, I read the DVO service procedure guides before changing the fluids on a 2nd hand fork I picked up & have struck an issue during the bladder bleed.
I followed the DVO bleed procedure from their website to the letter, but after I close the bleed screw with the shaft extended I can only cycle the damper through to half its stroke, it appears to be overfilled? & hydraulic lock occurs?.

I opened the bleed screw & compressed the shaft fully, then closed the screw again & could then cycle the shaft properly but thought I could hear air in the system.
I started the whole fluid change procedure again with the guide in front of me ,with the same result of hydraulic locking?, I then only compressed the shaft 1/2 way before installing the bleed screw. I can now cycle the shaft properly & can't hear any air in the system.

Am I going to ruin or burst the bladder by riding it or is their an issue with the bladder I should check before I ride it.
The bladder appears compressed when removing it from the cartridge tube, is that what it's supposed to look like?, I assume it fills with fluid when the shaft is compressed.
Have I missed something obvious or something not mentioned in the procedure?. or is this fairly normal.

any help is appreciated.

 

[Oddjob]

Give NS Dynamics a call or email DVO directly.

Sent from my SM-G970F using Tapatalk

 

[teK--]

Hi all, hoping someone is familiar with the Diamond or bladder bleeds.
I've serviced every fork I've owned but this is the 1st bladder fork I've changed fluids on, I read the DVO service procedure guides before changing the fluids on a 2nd hand fork I picked up & have struck an issue during the bladder bleed.
I followed the DVO bleed procedure from their website to the letter, but after I close the bleed screw with the shaft extended I can only cycle the damper through to half its stroke, it appears to be overfilled? & hydraulic lock occurs?.

I opened the bleed screw & compressed the shaft fully, then closed the screw again & could then cycle the shaft properly but thought I could hear air in the system.
I started the whole fluid change procedure again with the guide in front of me ,with the same result of hydraulic locking?, I then only compressed the shaft 1/2 way before installing the bleed screw. I can now cycle the shaft properly & can't hear any air in the system.

Am I going to ruin or burst the bladder by riding it or is their an issue with the bladder I should check before I ride it.
The bladder appears compressed when removing it from the cartridge tube, is that what it's supposed to look like?, I assume it fills with fluid when the shaft is compressed.
Have I missed something obvious or something not mentioned in the procedure?. or is this fairly normal.

any help is appreciated.

The bladder in the DVO works opposite to systems like Fox FIT or RS Charger. Instead of expanding when the fork is compressed, it collapses.

If your bladder is already collapsed when you have the fork apart, you need to undo one end of the bladder (it's just a metal clip) then manipulate it a bit so it pops back out into a plump shape before you do the clip back up.

The bleed nipple should always be done up with the damper rod fully extended.

 

[peanut]

cheers tek, that makes sense then as to why it's overfilling.

 

[sebbyreddan]

The bleed nipple should always be done up with the damper rod fully extended.

Definitely close bleed port at full extension. (Although I have seen posts on DVO Owners Facebook page where they have been recommended to close the bleed nipple with a half inch of travel used, I suspect this is to compensate for a slightly collapsed bladder.)
I have never needed to do this and not had issues with my bladder even though it looks slightly compressed, until i try to insert it where it evens out on insertion.

The bladder should only have air in it, this volume of air compresses when the shaft moves into the damper body and reduces the volume available for the oil.
How you have set it up will possibly rupture the bladder or at least allow air to burp out out the top or bottom of the bladder into the oil space.
Try a full bleed again, trying to ensure the bladder is fully expanded before reinserting it into the oil fill damper, then bleed it of any further air in the system. Close it up at full extension and hopefully you have full travel, if not check the bladder again, or as a last resort try opening the bleed port and move it 5-10mm in, close the bleed port and try again.
Is your bladder a new one? Sometimes you need to squeeze the bladder when re assembling to ensure it is expanded properly as you seal it up.

 

[peanut]

Thanks for the tips, i decided not to ride it & sort it out first.
I removed a clip & massaged the bladder out of it's compressed state, i did the whole fluid change from scratch again & it worked properly as per the service guide.
I think I'll check it occasionally & if it returns to a compressed state, I'll change the bladder.
This fork is actually a temporary replacement while my mattoc pro is away for warranty work, so I'm keen to keep it operational.
Now if only it would stop raining so I can test ride it.
cheers.

 

[teK--]

Good stuff. If it keeps returning to the compressed state then it suggests the bladder is worn and leaking at the seals when the fork extends, thus sucking the air out of it. DVO sell the bladder and clips as a spare part.

 

[Mattyp]

So found this thread after @leitch said he remembered reading something on here about it.
Both of my forks I've serviced recently have had a collapsed bladder. Also got a mate to check his today and his was the same. Suspect it happens over time and so slowly that you do not notice. Once fixed and re-bled fork adjustments become very obvious in particular HSC. I haven't been for a proper ride yet but even just bouncing on the forks down the street and riding up gutters its very noticeable. Prior to this I was wondering why I'm so shit at noticing any difference between No HSC and Full HSC. I think there will be some re-tuning on the next few rides.
Check your bladders folks, or get someone to help you.