A complete rebuild on this shock required a damper bleed and IFP depth setting. This the process I developed which works well:
- push IFP all the way down the damper tube;
- clamp damper tube upright in vice fill with shock oil;
- remove 4mm allen screw from shock bleed port;
- insert damper piston and rod into shock and screw seal head into damper tube - oil will start to force its way out the shock bleed port;
- once seal head is screwed right into damper tube, angle shock in vice so bleed port is the highest part;
- insert bleed screw and cycle shock a few times, shock will not compress fully as the there is too much oil in the damper and the IFP can't move because its bottomed out in the damper tube. Cycling the shock will migrate air in damper towards the bleed port;
- after cycling the damper several times, connect your shock pump to the IFP valve and pressurize the IFP (any pressure will do, so 100psi) and then gently crack open the bleed port. Air and oil will start to flow out the bleed port as the pressure in the IFP moves the IFP up from the bottom of the damper tube;
- once air stops flowing and only oil is coming out of the shock then the damper will be properly bled so we can move on to setting the right IFP depth;
- close off the bleed screw and drop pressure in the IFP down low enough that you can cycle the shock through its stroke. At this stage in the process you should not be able to compress the shock fully because the IFP is still set too deep and therefore there is too much oil still in the damper;
- to reduce the IFP depth, we repressurize the IFP and crack open the bleed screw to slowly let oil out of the damper until we get the full range of movement from the shock.
You may need to repeat this cycle of pressurize, bleed, depressurize and test several times before you get the IFP to the right depth.
IFP fill port adapter
I use an adapter that came with my SKS shock pump. Several mods were required to get it to work perfectly:
- a larger o-ring so the seal against the damper body would be better;
- drill out the centre of the adapter with a 2.5mm drill - this means the adapter will not be able to depress the middle of the valve core;
- inserting inside the adapter a length of plastic rod so that the valve core is only depressed when the shock pump is screwed fully onto the adapter - this allows us to pressure and then remove the shock pump without loosing all of the air from the IFP.