How I have been refilling shocks for 40 years and saving quite a bit of money. One small mistake regarding the oil drained out, I should have said that it started life as 10 grade but ends up at about 5 or less, which is why the shock becomes pretty useless. Replace with new 10 grade to get back to original, ot thicker, 20 or 30 for increased damping and less body lean on corners.