Shocking News - Check Your Shocks

David Hosie

It's all my fault
RAW
Dec 15, 2022
55
42
18
Sugar Land, TX 77479
rushautoworks.com
You fill your tank, you put air in your tires, but do you check your shocks?

Your shocks need to be operating properly for the car to give its best performance in the turns.

We have people sending back shocks because their leaking oil.

Now a small amount of oil leakage is totally normal, there will always be a small amount of oil bypasses the seals each time the shock moves, just as it does on the piston in your engine. It will accumulate on the shaft and since its ultra-low viscosity it will drip off the end.

More than that is an issue, it can be that the compression and rebound adjusters were screwed out too far, that will cause a big leak.

However, we are seeing a number with blown seals. The number one cause, the N2 charge, has been lost. When that happens, bad things happen in the shock.

The nitrogen charge drives the nitrogen piston to keep the shock oil under pressure and to stop cavitation. It also compensates for the volume displacement when the shock shaft is pushed into the cylinder.

When the nitrogen charge is lost rather than compressing the oil when the shock is compressed, the lower section goes on vacuum causing cavitation and the shaft seals to be reversed over every bump. That damages them. Then you get a bigger leak, and the shock needs to be rebuilt.

Why does the nitrogen charge leak off. Nitrogen is a very small molecule, it will find the smallest of leaks anywhere, typically at the Shrader Valve or NPT fitting.

So how often should your shock pressures be set? At least once per day. The nitrogen charge will bleed off within a week of sitting in most cases to a level where it is too low to stop cavitation. We need a minimum of 200psi and fill to 300 psi in the shop.

Do I have to spend hundreds of dollars on a N2 bottle and charge system? NO!

We recommend N2 but using AIR rather than nothing is 100 times better. The downside of air, it will change pressure more with temperature. This is insignificant in the overall operation of the shock, the change in pressure causes less of a force change than the tolerance between different springs. The other negative of air is it contains moisture which can cause corrosion. This will be over a long period, the shock will need replacing before this is an issue.

95% of our drivers will not be able to feel any difference between a shock charged with nitrogen and one filled with air. However, 95% of drivers will feel the difference in cornering from a shock that is charged vs not.

So can I use a simple pump. Yes, here are links to the three items you need to be able to charge your shock using air.

300 psi shock pump $ 18.47

https://www.amazon.com/gp/product/B092Z7Q1DV/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Shrader Valve $ 2.78

https://www.amazon.com/Control-Devices-Brass-Tank-Valve/dp/B0081TJO72/ref=sr_1_13?keywords=schrader+valve+1/8+npt&qid=1674080635&sr=8-13

No Loss Chuck $ 39.95, I really like these.

https://powertank.com/products/pt-shock-chuck

So a total of $ 61.20 or Less than a rebuild on 1 shock!

OR
you can buy an N2 System from Power Tank too. $ 559.95

https://powertank.com/products/shock-boss-ori-edition-portable-n2-tuning-kit
 
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John H

Rush SR Owner
Jan 1, 2023
39
14
8
De Leon Springs, FL 32130
Hi
Could you make a video how to put N2 for the newbies? Never done that. Thanks
It's easy. Get shocks to full droop, hookup to the shock schrader (purge tool volume first if you want). Pressurize the adapter to 300psi, screw in the no loss top to activate the shock schrader, make sure pressure is still 300psi, unscrew the no loss top to close the shock scharder, disconnect everything.

P.S. I have a red M coupe too.
 

David Hosie

It's all my fault
RAW
Dec 15, 2022
55
42
18
Sugar Land, TX 77479
rushautoworks.com
A puddle, not drips but a puddle. Bottom body of shock will get oil on it in normal usage.

Guys please also be aware that hauling a car half way across country in a conventional sprung trailer, beats the heck out of just getting there! Shocks should be the first thing you look at coming out the trailer, then a good visual for anything that has come loose. I actualy broke a shock on one of the formula cars one time hauling it in a regular trailer.
 

GTwo

Rush SR Owner
Jan 26, 2023
2
0
1
Cocoa, FL 32926
The pump you suggested has a no loss chuck. What is the second one necessary? Also, do the shocks not have Schrader valves on them? Why do you need the new ones you listed?
 

David Hosie

It's all my fault
RAW
Dec 15, 2022
55
42
18
Sugar Land, TX 77479
rushautoworks.com
The pump you suggested has a no loss chuck. What is the second one necessary? Also, do the shocks not have Schrader valves on them? Why do you need the new ones you listed?
The pump really does not have a proper no loss valve, the picture attached is the assembly of the pump, shrader valve and no loss valves listed. Shrader to connect pump to no loss valve. The pumps no loss valve, its really finicky and a pain to use that's why I recommended the addition valve. If on a budget yes the pump alone can be used.
 

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GTwo

Rush SR Owner
Jan 26, 2023
2
0
1
Cocoa, FL 32926
David, I used it to pump up my shocks on my 996. The non-proper no loss valve worked fine but I can see how a Schrader and the nicer no loss would work better. I can tell you though it was really hard to pump once the PSI got over 200. I was getting about 1 psi per stoke at that point and it was only the last tiny bit...maybe .5 cm of stroke and that took a lot of force. Nevertheless it worked.
 

David Hosie

It's all my fault
RAW
Dec 15, 2022
55
42
18
Sugar Land, TX 77479
rushautoworks.com
David, I used it to pump up my shocks on my 996. The non-proper no loss valve worked fine but I can see how a Schrader and the nicer no loss would work better. I can tell you though it was really hard to pump once the PSI got over 200. I was getting about 1 psi per stoke at that point and it was only the last tiny bit...maybe .5 cm of stroke and that took a lot of force. Nevertheless it worked.
Bud maybe I should have been clearer on that point! Yeh the pump gets you there but at my age it’s a work out. Ha! It’s a $20 solution to a $600 problem for some, so I wanted to bring it up as an option. N2 is the way to go always, but it’s not something that will work for a lot of our customers. I bet Ben Glenn could get 400psi out of that thing If you challenged him! :)
 
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