[Yans van Horn]

I bought some time ago a new (removed from a new bike) swinger 4-way air (190mm/50mm version, 2004) and mounted it in a 5-spot. Few observations:

1. It has quite a lot of stiction. Even with ~30psi in main and 0psi in SPV it is very hard to compress it in hands (not mounted)

2. With normal pressure (140psi main) it does not fully extend (reaches about 183mm)

3. With main chamber pressure is increased to ~230psi it extended to 186psi (still 4-5mm short of 190mm).

4. When pumped to normal pressures 130/40psi (main/spv) - when mounted, shock appears to be working ok.

Does anyone suspect what can be a problem (extending, stiction) ?

My guesses:
- Maybe there is too much grease/oil in negative chamber and shock cannot fully extend ?
- Maybe there is no grease at all (that would explain stiction) and because of stiction shock cannot extend ?
- Problem with inner seals (positive-negative leak) ?

I would like to disassemble it and check for possible problems, but i lack few necessary tools:
- "Air Shock Cap Socket (p/n 85-4418)" for the air piston. Is it possible to use some standard tool ?
- "Air Canister Seal Guide"
- "IFP tool" - maybe somene who own one could tell me how deep should be the IFP piston positioned (when assembling) assuming that shock has 50mm travel ?

I have experience in disassembling/servicing/tuning my forks: rs mag21, manitou mars, black super air, minute 3 but haven't done it with dampers (yet ;-). Any warnings/guidelines ? I've read thoroughly service guide. It seems pretty straightforward. Only problems could be caused by missing tools, but maybe with Your help it could be done

 

[Yans van Horn]

After making one tool, modyfing other one, borrowing thrid from a friend - operation of dissassembling swinger shock was completed. After dismantling and inspecting all parts in search of a possible cause i assemmbled the shock without any problems - piece of cake Now fresh castrol blood flows through its veins And slick honey helps seals move smoothly After pupming to 200psi and submerging in water, no bubbles can be seen...

So the work is complete - extension problem and stiction are gone (hopefully forever).

PS: inside, there is one fat (3-4mm?) o-ring limiting extension (its purpose is to cushion top-out). So the shock reaches full 190mm only when pumped to more than 160psi in main air. No problem - I can live with 2mm less (130 psi). Maybe when i'll will service it again i will change it to 1-1.5mm.