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IV Shock Air Sleeve Maintenance
Note: The following maintenance procedure applies only to the re-lubrication of original air sleeve seals used in IV rear shocks. IV rear shocks are not 100% user serviceable, meaning that if seals or rings are found to be in need of replacement, this level of service must be done by FOX Racing Shox service or an Authorized Service Center. If seals are found to be so worn or damaged, or have suffered any damage in the course of your following this air sleeve maintenance procedure, be advised that at this point you will need to contact FOX Racing Shox or an Authorized Service Center to schedule repair service.
WARNING: FOX air shocks contain high air pressures. Improper handling may cause SERIOUS INJURY or DEATH. Before servicing a FOX air shock, certain precautions must be taken. Follow these steps to prevent serious injury, and always wear eye protection. If you do not feel confident about performing the following procedure, contact FOX Racing Shox or an Authorized Service Center to schedule a service repair.
CAUTION: For your protection, wear safety glasses throughout this procedure.
- Before beginning service,
you need to make sure that the air shock you are servicing is not "stuck-down".
A stuck-down shock is one that is frozen at the bottom of its travel,
and will not return.
- To determine whether the shock is or is not stuck down, the first step is to pump up the main air chamber to 250 psi with a FOX High Pressure Pump.
- The shock may extend
slightly; however, the shock might still be stuck down. Continue cautiously with the next step.
- Release all the air pressure
from the air sleeve air valve.
- Cycle the shock a few
times, then release air pressure from the air sleeve air valve again. Measure the eye to eye distance for your shock, and record this number in inches or millimeters. With the Mini model, the eye to eye measurement extends from the center of the shaft eyelet to the center of the body eyelet. With the Stumpjumper™ model, the eye to eye measurement extends from the center of the shaft eyelet to the flat on the body end.
- Refer to the "Eye to Eye Measurement" for your bicycle model in the SAG Setting Guidelines table. Subtract the number you recorded in the prior step from your shock's measurement in the table. If the difference is greater than .375 inches (or 9.5 mm), your shock is most likely in a stuck down state. Your only choice at this point is to send it to FOX or an Authorized Service Center for repair. If the difference is less than .375 " (or 9.5 mm), proceed with caution.
- Remove the mounting
hardware, and remove the shock from the bicycle. With the Stumpjumper™ model, it's better to remove the shock and the together as a unit, as the shock extension will serve a helpful purpose later in this procedure.
- Remove all the spacers from the shock and set these aside on a clean shop towel, noting which came from the shaft eyelet and which came from the body eyelet. With the Mini model, it's only necessary to remove the body side pin; remove it now and set it aside. If you're working with the Stumpjumper™ model and the shock extension is still attached to the shock, separate these now.
- Place the body eyelet end of the shock in
a soft-jawed vice, being careful not to over-tighten and crush any shock parts. Slip a 6 mm Allen wrench through the eyelet at the shaft end of the shock and attempt to extend the shock by pulling the shaft straight out.
If you can extend the shock to the full eye to eye length (per the eye to eye measurement for your shock in the SAG Setting Guidelines table), proceed with the next step. If you cannot extend the shock to the full eye to eye length per the eye to eye measurement for your shock, this confirms that the shock is indeed stuck down. Your only choice here is to contact FOX or an Authorized Service Center to schedule repair service.
WARNING: DO NOT PROCEED FURTHER WITH THIS PROCEDURE IF THE SHOCK IS CONFIRMED TO BE STUCK DOWN. Proceeding any further risks your suffering of SERIOUS INJURY or DEATH.
- Remove the body eyelet end of the shock from the vise, flip it and place the other eyelet (shaft) end into the soft-jawed vise, as you did in Step 9. If you have a Micro model shock, place a shop towel halfway through the eyelet at the body end to prevent the air sleeve from coming off. If you have a Stumpjumper™ model shock, re-install the shock extension finger-tight for the same purpose. Use a strap wrench to turn the air sleeve counterclockwise, to unthread.
Note: YOU MAY HEAR A VERY LOUD POP WHEN YOU REMOVE THE AIR SLEEVE! The loud pop is a normal indicator of a stuck-down shock, and your only choice at this point is to stop this maintenance procedure right here and contact FOX Racing Shox or an Authorized Service Center to schedule repair service. If you did not experience a loud pop, continue with the next step.
- Finish unthreading the air sleeve by hand and pull it away from the shaft.
- Remove the shop towel (or the shock extension) from the body eyelet. Rotate the hose so the metal "noodle" (the metal elbowed end of the hose coming from the external reservoir) is oriented to the body eyelet as shown in the figures below. This will allow enough clearance to get the air sleeve past the noodle. Next, carefully pull the air sleeve over and past the noodle.
Figure 1: Stumpjumper Noodle
Figure 2: Micro Noodle
- Clean the inside of the air sleeve with isopropyl alcohol.
- Clean the all internal parts with isopropyl alcohol.
- Carefully inspect all the seals. Remember that if seals are found to be worn out or damaged, or have suffered any damage in the course of this procedure, you will need to contact FOX or an Authorized Service Center to schedule repair service.
- After thoroughly cleaning and inspecting the seals and o-rings for any damage that would require them to be replaced, and all the internal parts pass this inspection, lightly lubricate all seals and rings with half a pillow pack of FLOAT Fluid.
- Make sure the noodle is properly aligned, as per either Figure 1: Stumpjumper Noodle or Figure 2: Micro Noodle. Slide the air sleeve
onto the body, but do not thread the air sleeve on at this time.
- Place 2 cc of FLOAT Fluid into the air sleeve. Do not thread the air sleeve on yet.
- Install the travel indicator o-ring onto the body. Place all spacers back onto the body eyelets. On the Stumpjumper™ model, again re-install the shock extension.
- Mount the shock back
onto the bicycle with the appropriate mounting hardware. Tighten the bolts
to the bicycle manufacturer’s torque specifications.
Note: Due to frame design, you may need to tighten the air sleeve before re-installing the shock.
- Turn the Brain Fade™ adjust knob completely counterclockwise. Press down on the bicycle
seat to compress the rear suspension; this will make it easier to thread on the air sleeve. Tighten the air sleeve by hand until it is snug. DO
NOT over-tighten with a strap wrench or other tool!
- Inflate your shock with the FOX High Pressure pump. Next, adjust rebound and Brain Fade™ per the procedures on the Specialized® Inertia Valve (IV) Shock product page.
- Go ride.
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