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Old 12-03-2007, 12:50 AM   #1
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Default Shocks with no volume compensator - do they need air to work?

How can a shock with no volume compensator (foam or bladder/diaphragm) work properly? The shock oil won't compress as the shaft goes in.

I'm having problems building the shocks on my new RC10B4 FT. If I bleed oil out to get the rebound correct, I can hear air bubbles passing through the piston holes - a sort of sucking noise.
If I don't bleed some oil out, they hydrolock, or they get tight when compressed and then rebound all the way.

Seems to me that these shocks need to have a small amount of air in them to work.
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Old 12-03-2007, 03:01 AM   #2
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How can a shock with no volume compensator (foam or bladder/diaphragm) work properly? The shock oil won't compress as the shaft goes in.

I'm having problems building the shocks on my new RC10B4 FT. If I bleed oil out to get the rebound correct, I can hear air bubbles passing through the piston holes - a sort of sucking noise.
If I don't bleed some oil out, they hydrolock, or they get tight when compressed and then rebound all the way.

Seems to me that these shocks need to have a small amount of air in them to work.
Yep...they're called "emulsion" shocks.

Here's an old-ish article, but it's still pretty relevant.

http://findarticles.com/p/articles/m...04/ai_n8929368
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Old 12-03-2007, 04:43 AM   #3
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I just squirt em full of oil, screw the cap on, Push the piston in till is stops, usually at just over the half way point, crack the cap open a half a turn, drive the piston in the full amount, loosening the cap a little as I go if needed.

When I get full travel I crank down the cap.

Shock feels the bizzo when compressed by hand, and works like a charm when bolted onto the car.
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Old 12-03-2007, 10:26 AM   #4
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Yep...they're called "emulsion" shocks.

Here's an old-ish article, but it's still pretty relevant.

http://findarticles.com/p/articles/m...04/ai_n8929368
Thanks for the link - nice to know that I was trying to achieve the impossible.

The article also says to pump the shocks before use, to re-emulsify the oil - good advice, now I know the air is supposed to be there.

One more question - do the top B4 drivers use the shocks standard, or do they mod them with compensators or bladders?
If they use them as standard, that's good enough for me.
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Old 12-03-2007, 10:31 AM   #5
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I just squirt em full of oil, screw the cap on, Push the piston in till is stops, usually at just over the half way point, crack the cap open a half a turn, drive the piston in the full amount, loosening the cap a little as I go if needed.

When I get full travel I crank down the cap.

Shock feels the bizzo when compressed by hand, and works like a charm when bolted onto the car.
That's basically what I was doing. This method works fine on my older B4FT, which I bought secondhand, but is proving tricky with my new one. I guess the moulds for the shock caps are past their best. It's extremely difficult to pump out the excess fluid, unless the cap is unscrewed at least 2 turns. This in turn means that, when I tighten the cap, I'm trying to compress the extra 1 1/2 turns-worth of fluid.
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Old 12-03-2007, 12:09 PM   #6
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Do yourself a favour and get 2 packs of Yokomo #YS8Y. They are shock caps that fit onto the AE shocks with bleeder screws in them. So all you have to do to build the shocks is over fill them a bit, compress the shaft all the way, all the excess oil will go out of the little hole in the cap, then screw the bleeder screw back in, extend the shaft, and your done with perfectly bled shocks and equal rebound.
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Old 12-03-2007, 02:37 PM   #7
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I just bought 5 packs of the Yokomo YS8Y's to do all the shocks on both my B4 & B44, They cost me a lot! And guess what, They don't Fit the AE shock!!
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Old 12-03-2007, 03:50 PM   #8
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I just bought 5 packs of the Yokomo YS8Y's to do all the shocks on both my B4 & B44, They cost me a lot! And guess what, They don't Fit the AE shock!!
Hope you only had to open one pack to find that out and can return the other four.
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Old 12-03-2007, 06:43 PM   #9
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Yep! I only opened one pack! But as I got them from a shop on ebay, I can't return them! so now I'm stuck with $30 of Yokomo shock caps that I can't use But what I have ended up doing is to drill some holes in AE caps and just use the screws for the Yokomo pack!
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