Leaky shocks are bugging me now.....

murphy0987

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I used this size and was able to fit 5 per cartridge. You can reference that size and find something local to you I’m sure. My shocks have been bone dry for months now, even after bending several thousand shock shafts.

uxcell O-Rings Nitrile Rubber 2.6mm Inner Diameter 7mm OD 2.2mm Width Round Seal Gasket 50 Pcs https://www.amazon.com/dp/B07X2Y4956/ref=cm_sw_r_cp_api_i_XFTxEbS6GV918
I tried these amazon orings in my 3s shocks. I could only fit 4 orings in per cartridge. They stopped the leaks, however there was too much resistance on the shock shaft with the bigger orings and made the shocks much stiffer.

So then I pulled apart come traxxas ultra shocks i had laying around, and removed the orings from them. I replaced the bottom oring in the 3s shocks with one of the blue traxxas orings and used the stock oring for the top. Used green slime and reassembled the shocks. So far so good, no leaks. Ive only tested them about 3 times so far, but so far so good.
 

Matt6453

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I can't seem to work out how to find the link within the eBay app but just search for:

Nitrile 2.5mm ID x 2mm C/S O Ring. 2.5x2. Choose Quantity. New. Metric
 

AndyBell

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@Matt6453 Just wondering if you got your o-rings and if you've managed to pop them in yet?
 

Matt6453

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@Matt6453 Just wondering if you got your o-rings and if you've managed to pop them in yet?
Not arrived yet, they might be at home as the post comes after I leave. I've got loads on so not sure when I'll do them anyway, I've got a body I want to trim and paint next.
 

SrC

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In theory, a shocks seals don't need a lube. The shock oil ultimately does the job. A lube is really for initial assembly and ends up mixing into the shock oil anyway. But if a lube if used should be compatible with the type rubber/silicone its used on. Some petroleums deteriorate silicone for example. Green Slime is an Associated shock lube compatible with Silicone, it is waxy compared to others like Protek Premier Blue shock lube. I have both on hand. Green Slime has been the top go to for 30 years. If using Butil o-rings/seals(harder) they are less prone to chemical reaction to lubes and don't swell. Butil seals need to be more precise in size, where silicone generally swells up to size. FYI, even silicone plumbing faucet lube is perfect for silicone O rings/ X-seals. Silicone seals naturally swells a bit with shock oil. I place my o-rings in a plastic bag and put lube or silicone in there and smush around and let stand overnight. When you build the shocks the o-rings will seal better out the gate. I find this helps most of the time. Apparently some shocks come with poorly sized seals. Sometimes modifying the spacer between them will compress them more and seal better within the cartridge. I always polish my shock shafts with a metal polish on my drill with fresh rebuilds. Shocks become more plush/ less sticktion. Most of the time I assemble the bottom cartridge onto the shock shaft first and place my piston onto the shaft last from the top. It is the reverse of most manual instructions. Many track guys do this. This avoids possible tearing of the seals. Just some ideas.:cool:
 

AndyBell

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Some very useful info there, thanks.
 
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AndyBell

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Thought I'd post back on my findings, so I got some of the uxcell o-rings that were suggested, they did not work for me at all. Firstly I couldn't get 5 in comfortably. I reassembled with 4 in each shock and they were leaking before I even put them back on the truck. Too tight on the shaft as well which I think would cause problems in itself.

Manually compressing them made the shock oil ooze out of the small cap and cover the shock shaft so I just pulled them all apart again and reassembed with the stock parts. I'm not sure if they sent me a wrong size but I have no way of reliably measuring them.

On the pic below the stock o-ring is on the left and the uxcell one on the right.

IMG_1567.JPG
 

SrC

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Sourcing O-rings other than OE can be a bear. Its hit or miss. Sometimes you get lucky with the right size and a Buna material. Buna doesn't swell like silicone o-rings. So buna must be exact in dimensions to OE. Silicone ones generally swell up with silicone oil. And by design, they are more forigiving with dimension. Buna types can be too tight and cause binding/sticktion. That goes against the shocks performance. Sometimes the sticktion is so tight that it becomes a friction shock, and a 30weight oil setup will feel like the shock has 80 weight in there. Silicone ones will swell always to size. If that makes sense.:cool:
edit:
Sometimes even a fresh rebuild with OE parts will be too tight when done until they breakin, o-rings swell and all. Thats why its good to use a lube like Green slime, Protek premier Blue or even a plumbing silicone o-ring lube along with a light polish of the shock shafts.
Soak the O-rings in a bag with the lube of choice and mush them around. Even let sit overnight. The o-rings will be more pliable and absorb the lube. Even just placing the silicone oil in the bag with the o-rings works.
 
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