Losing air when unscrewing shock/dropper pump - time for new pump?

[Mr. Breeze]

I replaced my dropper post with a new OneUp V2 and when I go to unscrew my Syncros SP2.0 pump (which is only a couple years old) all (and I mean ALL) the pressure out of the dropper is lost. I haven't had this issue when filling shocks or even the OEM (Specialized Command Post) dropper.

There shouldn't be any loss when unscrewing (just the air from the pump tube) so is the problem:
1) the Syncros pump nipple has gone bad and time to buy a new pump
2) the valve on the OneUp dropper post is defective

Thanks!
Scott

​

 

[Mikerb]

no 2

 

[Mr. Breeze]

no 2

Not sure what you mean.

 

[levity]

no 2

no. 2

fify

 

[sethimus]

use your brain

 

[Mr. Breeze]

No need to be an ass.

A little clarity is all I asked. If you can't be helpful, then just don't take the time to respond.

 

[Polar]

use your brain

You need a brain

 

[Mr. Breeze]

SMH - if you can't be helpful, just move on.
I guess I shouldn't expect people to be respectful.

 

[Streddaz]

I replaced my dropper post with a new OneUp V2 and when I go to unscrew my Syncros SP2.0 pump (which is only a couple years old) all (and I mean ALL) the pressure out of the dropper is lost. I haven't had this issue when filling shocks or even the OEM (Specialized Command Post) dropper.

There shouldn't be any loss when unscrewing (just the air from the pump tube) so is the problem:
1) the Syncros pump nipple has gone bad and time to buy a new pump
2) the valve on the OneUp dropper post is defective

Thanks!
Scott

​

So, you are definitely using the two step release on the pump? There should be a part that you unscrew first that seals the valve before you unscrew the hose from the valve.

Does the valve lose pressure without the pump attached? Maybe it needs a new valve core.

 

[Mr. Breeze]

So, you are definitely using the two step release on the pump? There should be a part that you unscrew first that seals the valve before you unscrew the hose from the valve.
View attachment 140145
Does the valve lose pressure without the pump attached? Maybe it needs a new valve core.

I thought I had been doing the 2 step release process, but I now notice that the release ring had seated itself against the metal barrel so when I was twisting the release ring, the barrel was also unscrewing.
Thank you for your note and calling out the 2-step process. That did the trick!
Thanks again for your help!

 

[Streddaz]

I thought I had been doing the 2 step release process, but I now notice that the release ring had seated itself against the metal barrel so when I was twisting the release ring, the barrel was also unscrewing.
Thank you for your note and calling out the 2-step process. That did the trick!
Thanks again for your help!

No worries, glad it worked!

 

[Singletrackmind]

I use this pump which has a way to Bleed the pressure so you can unscrew the pump from shock/Fork without losing any pressure. Kinda expensive, but to me it's worth it. My riding buddies pump about 5psi extra because they know they will lose some pressure during Disconnect.

Sorry about the A-hole responses from certain members. Hav3 found mist people respectful and helpful on this site.

SHOCK DIGITAL DRIVE

Bicycle shock pump built from CNC-machined aluminum and steel construction with varnished wood handle. Ultra-narrow barrel provides efficient tuning up to 300 psi. Chuck features rapid-release tuning and an innovative zero-loss disengagement mechanism. Extremely accurate digital gauge. Presta...

ride.lezyne.com

 

[Downhillr]

Some of us in ride group use this one because you can carry in backpack as needed for on trail use…

DIGITAL SHOCK DRIVE

The ultimate bicycle shock pump for trailside tuning. Incredibly compact and lightweight aluminum construction. Ultra low-profile digital gauge built into the side. Zero-loss chuck design unthreads from the shock after valve pin seals. Ideal for mountain bikes. Up to 350 psi (24 bar).

ride.lezyne.com

 

[Mr. Breeze]

Thanks for the suggestions on the Lezyne pumps. I'll definitely check them out.

 

[Streddaz]

I use this pump which has a way to Bleed the pressure so you can unscrew the pump from shock/Fork without losing any pressure. Kinda expensive, but to me it's worth it. My riding buddies pump about 5psi extra because they know they will lose some pressure during Disconnect.

Sorry about the A-hole responses from certain members. Hav3 found mist people respectful and helpful on this site.

SHOCK DIGITAL DRIVE

Bicycle shock pump built from CNC-machined aluminum and steel construction with varnished wood handle. Ultra-narrow barrel provides efficient tuning up to 300 psi. Chuck features rapid-release tuning and an innovative zero-loss disengagement mechanism. Extremely accurate digital gauge. Presta...

ride.lezyne.com

The pump @Mr. Breeze has should loose any pressure when you remove it as you unscrew the inner knob first and that closes the shock valve, then you unscrew the hose. Most shock pumps have this feature. You won't usually find that on a pump for tyres as the air volume is much larger and the pressures are way less.