Guys,
If you intend to drain the shock you're best off to open both the small
filler plug (1/4" Whitworth) and the large which is the valve (7/8" US).
When you open the valve, also extract the springs and shims, if any. Think
of the shock as having an upper and lower chamber separated by the pistons.
The pistons each have a poppet valve in them to allow the oil to go in one
direction only. You _can_ empty/refill/bleed the shock from only one of the
2 places, but save the task for a long weekend. Remember that air rises, so
keep the hole you're filling the highest point. Fill the valve end first
over full. let it sit for awhile, don't move the arm, reinsert the valve
stuff. Turn the shock up so the small plug is up. (1/4 eliptoids have the
plug on the lid, semi-eliptoids on the body). Overfill through the plug,
let stand a while. Add more and move the arm slowly the full range (it will
act like a shock at this point, the plug need not be in), let stand, add
more and reinsert the plug. If when you move the shock arm it is "locked",
then you still have air at the valve. If it seems to change from hard to
soft in 1 stroke, then you've gotten dirt in a poppet valve.
Having said all that, which I hope is helpful, why do you _want_ to
drain
and fill the shock. If there is the correct amount of oil in the shock
(meaning it aint leaking) there's no reason to remove the oil. It's not
contaminated or suffering from "thermal breakdown". If oil has escaped,
then topping up is all that is required. If the oil is running out, replace
the shock. Only if the oil can get out is there a chance for dirt to get in
which would be the only justification for changing it. Just my .02
Hope this helps. Peter C
At 01:00 PM 3/15/99 , Bill & Cindy wrote:
>List,
>
>I have a pair of rear shocks on the bench which I would like to drain,
>flush and re-fill.
>
>My question is...which fitting is the correct one to use? The big nut, that
>would be on the bottom of the shock when fitted on the car, or the little
>one (which no standard or metric wrench fits, must be Whitworth!) on the
>side near the top and 'neath the cover of the shock?
>
>After checking the archives...I read where Peter warns that the shock must
>be laid flat on the bench when bleeding...this leads me to think that the
>little fitting is the culprit.
>
>Thanks,
>
>
>Bill & Cindy
>
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