[dhosinski]

Hello:

I have a 2003 Giant NRS that I picked up last year for a friend. The bike is extremely clean, and was never ridden on a trail. Infact it sat most of the time.
When I air up the rear shock (RS SID XC) both the positive and negative chambers hold pressure. After riding maybe a day or so the pressure drops in the negative chamber. If I understand correctly, the main shaft piston seal seals between the pos / neg chambers so if it were bad it both chambers would empty? Can someone clarify that for me? Now, that leads me to believe the Schrader valve is the likely culprit? Are these valves standard valves, or is there something different about them?

I plan on going through the shock, clean and relube. Hopefully this will address the leak. Or, does someone know what the o-ring/seal numbers are as they are no longer available from RS?

We also plan on getting rid of the front fork. Too many bad reviews and I don't want my friend to have a bad incident should it fail.

Thank you!

 

[mullen119]

How are you finding out that its low on air? If you attach a pump to the valve, the air will move into the pump. On a volume as small as a negative chamber, that be be a 30-40psi drop that the gauge shows.

If it is leaking and its from the negative side only, it will be either the valve or the seal on the air can that seals the can and shock body. Probably going to have a hard time finding a seal kit for such an old shock, but look around on ebay or something similar and you may get lucky.

 

[dhosinski]

I agree that when I reconnect the pump the 50 psi will almost completely be lost.
I plan on just determining the seal sizes/types, and replacing them. Also, does anyone know if the Schrader valves are standard, or where I can purchase one?

I just want to buy a little time until we can purchase a new bike (simply because it's old technology).

Thanks

 

[mullen119]

Fill the shock with air to like 250 psi and dunk it water. If its leaking, it will show you where with air bubbles. If there is a leak at the valve, you can replace the valve core to solve the problem.

 

[dhosinski]

Thanks, I was thinking of shooting it with soapy water, but the bucket will likely be better.