Corally shock bladders

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danl

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Corally RC's
  1. Kagama
  2. Spark
Does anyone find that the Corally bladders are ineffective at sealing the shock? On both my Kagama and Spark shocks, their was fluid on the cap side of the bladder. Both were about 60% filled upon tear down. In my case, with all the air in the shocks, the dampening is "light". Filling the shocks with any oil will make it feel more dampened. They feel like normal rubber but they say they are "silicone". I had two new Traxxas GT Maxx shock bladders that fit and they are for sure silicone. They are more pliable in the hand while sealing the shock better, providing a better bleed.

Just wondering if anybody is using a different bladder than stock. If not, I will use the Traxxas bladders as they seem to be more effective.
 
Not had any problems with them to be honest but the back shocks on the kagama 6s loved to leak but was just the caps coming loose, fixed that by putting plumbers tape on the thread.

Good shout on the maxx shock bladders fitting on them got a few myself I shall use next time I rebuild the TC shocks :D
 
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I have yet to actually run the car with the gt maxx bladders. On the bench, they bleed perfectly whereas the stock corally ones do not. Hopefully they don’t leak in use.

I think other bladders may work, it comes down to just being the proper outside diameter. Has anyone tried arrma 6s shock bladders,
 
I have that problem , it's caused by "over tightening" the shock cap and distorting the bladder seal but if you don't then the cap comes loose. Once the hard rubber bladder is distorted it will never again seal correctly. I have some O-rings on the way to experiment with to see if this can be fixed. You can find 8 packs of silicone 18mm bladders for the UDR shocks on Aliexpress that may work as an alternative. The problem with silicone bladders though is that silicone oil gradually invades and destroys silicone rubber.

Also I found that you can replace the sillicone shock shaft seals (and the spacer between them) with three of these viton O-rings:

https://oringsandmore.com/fkm-o-ring-3-68-x-1-78mm-minimum-50-pcs/
https://oringsandmore.com/fkm-o-ring-3-68-x-1-78mm-black-minimum-50-pcs/

These should last longer, are much more resistant to blowouts and have about the same amount of friction/resistance to the shaft moving. They requite a bit of compression to seal the shaft so it'll seem as if they don't work until the lower cap is tightened up. As with the stock seals they should be lubricated before installation.
 
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Both my kagama and spark had the bladders distort from the factory build. The gt maxx shocks have been rebuilt twice now and I reused the same bladders. They are fine a year later, no degradation. It looks as if I’ll get a minimum of two years out of the gt maxx silicone bladders. They may degrade, but I’m not seeing signs yet. The same is true of the shock shaft o rings. I did order 8 Amazon silicone bladders to fit the maxx slash, which uses gt maxx shocks. These are the same bladders that I stole from my gt maxx rebuild kit. The UDR shocks are different, I don’t think those will fit?

The diff o rings go bad much faster. I’m not sure if the heat accelerates how fast they try to swell on me. Both my Traxxas and corally diffs swell the o rings. I have buna n ones to try when I do a corally diff here, someday. It’s just that they don’t have failures, so I don’t get into them until I feel bad.
 
danl said:
Both my kagama and spark had the bladders distort from the factory build. The gt maxx shocks have been rebuilt twice now and I reused the same bladders. They are fine a year later, no degradation. It looks as if I’ll get a minimum of two years out of the gt maxx silicone bladders. They may degrade, but I’m not seeing signs yet. The same is true of the shock shaft o rings. I did order 8 Amazon silicone bladders to fit the maxx slash, which uses gt maxx shocks. These are the same bladders that I stole from my gt maxx rebuild kit. The UDR shocks are different, I don’t think those will fit?

The diff o rings go bad much faster. I’m not sure if the heat accelerates how fast they try to swell on me. Both my Traxxas and corally diffs swell the o rings. I have buna n ones to try when I do a corally diff here, someday. It’s just that they don’t have failures, so I don’t get into them until I feel bad.
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One thing to keep in mind is that the o-ring measurements in the manual are actually incorrect. The diff O-rings are not 5x8 you need something closer to 5.5x8.5. 5x8 will work due to the shaft stretching the O-ring out to fill the seat but 5.5x8.5 would be more ideal. I got Viton o-rings due do their increased wear and heat resistance vs silicone or rubber.

My understanding is that the UDR shocks have an internal diameter of 18mm the same as the Corally shocks. The off brand ones from Aliexpress and Amazon look identical to the GT Maxx bladders and are probably just the same bladders.
 
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The aftermarket shock bladders showed up and they fit just like the OEM Traxxas ones.
IMG_0634.webp


Here are how they fit in the corally shock caps:
IMG_0635.webp


And on the shock body:
IMG_0636.webp


After an hours of use the front shocks with the corally bladders were leaking to the cap side and had lots of air in them. The rear shocks which I had the Traxxas bladders in are still air free and no leaking. The corally bladders are a rubber whereas the Traxxas and aftermarket ones are actual silicone. I can actually get an air free zero rebound bleed with the Traxxas bladders. Shocks now feel great.

Hopefully this helps someone.
 
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Corally bladders are good for one use and that's it, when you open the shock again you have to replace them.
 
Atomic Skull said:
Corally bladders are good for one use and that's it, when you open the shock again you have to replace them.
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If they even last to the first rebuild. The spark bladders started allowing air in on the factory build. All four shocks.

I’m over 2 hours of runtime on the Traxxas bladders in corally shocks. Everything is working as intended.

The factory Traxxas shock bladders have been through at least 3 services on my maxx slash and still provide a seal. They are on track to last many years for me.
 
danl said:
The aftermarket shock bladders showed up and they fit just like the OEM Traxxas ones.
View attachment 11233

Here are how they fit in the corally shock caps:
View attachment 11234

And on the shock body:
View attachment 11235

After an hours of use the front shocks with the corally bladders were leaking to the cap side and had lots of air in them. The rear shocks which I had the Traxxas bladders in are still air free and no leaking. The corally bladders are a rubber whereas the Traxxas and aftermarket ones are actual silicone. I can actually get an air free zero rebound bleed with the Traxxas bladders. Shocks now feel great.

Hopefully this helps someone.
Click to expand...
I put these in my Asuga and Shiroi and they worked perfectly, that said don't torque the caps down too much the bladder can pop out of it's seat inside the shock if you do. Tighten it as much as you can with your fingers but don't put an object through the mounding hole and crank it down, finger tight is perfect.
 
Ok so something weird happened, one of the shocks on my Shiroi leaked all of it's oil out and when I opened it I found the GPM branded silicone Xmaxx bladder has dislodged and was rolled up inside the shock body. Moreover it would not stay put when I tried to reseat it, it popped back out and down inside the shock again. It seems to have swelled so it was oversized. I replaced it with another new one but I have no idea what caused this. As a precaution I completely drained and cleaned the shock and put fresh oil in it. All of the other GPM bladders that I have on my Asuga and Shiroi seem to be fine.
 
The 4 I put in my spark are still good. Perhaps you had a defective bladder or just one got twisted on install?
 
danl said:
The 4 I put in my spark are still good. Perhaps you had a defective bladder or just one got twisted on install?
Click to expand...
The weird thing is it looks like it has swelled somehow, maybe it just got distorted over time.,
 
I have two Traxxas and two gpm ones in my spark. I’ll report back if I have any issues with either.
 
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