Shocks

Filling and Bleeding Reservoir Shocks

I often get asked how reservoir-style shocks should be bled of air, since they are slightly different than a standard shock. The example below shows me preparing a Integy MSR4 reservoir shock for use. Be aware of the fact that the Integy MSR4, like many reservoir shocks, contains no shock oil in it when shipped from the factory. So before they are used you must fill them with the shock oil of your choice. The procedure below shows me filling the shock with shock oil and bleeding the air from the oil. This procedure is similar for all other reservoir-style shocks.

The first thing you'll need to do is to remove the reservoir portion of the shock. Once you do that you can fill the shock with the shock oil of your choice, just as you would a standard shock. I generally use 50 weight oil with my Integy shocks.

Once you have completely filled the main body of the shock with shock oil, move the shock shaft up and down slowly. You will probably notice air bubbles appearing in the fluid as you do this. This is typical when first filling the shock, and it's the air bubbles that you want to eliminate. Air that remains trapped in your shock prevents it from operating as smoothly as it should. Continue to slowly move the shock up and down until all the bubbles disappear. This procedure may take several minutes. You may also find it necessary to add more shock oil so that you keep the shock body full.

Notice in the picture below that the fluid has no air bubbles present in it.

After removing the air from the shock fluid, you need to place the reservoir on the shock. First remove the end cap from the bottom of the reservoir, then snug the reservoir down on the shock body itself. Don't try to over tighten the reservoir on the shock body however. Over tightening will only damage the o-ring seal that's between the two parts.

Once the reservoir cap is in place, fully compress the shock shaft into the shock body.

Once the shock is compressed turn it upside down. Then fill the reservoir with shock oil, so that it's between 1/2 and 3/4 full.

Once again move the shock shaft up and down slowly to remove air bubbles in the shock oil, except this time you are removing air bubbles from the oil in the reservoir.

When the air has been bled from the shock oil place the shock shaft in it's compressed position, so that it's inside the shock body. Then drop the foam spacer into the reservoir and replace the reservoir end cap. You should notice a small amount of shock oil ooze out of the reservoir as you tighten the cap. That just indicates that the shock is full of shock oil. If you have not had excess oil ooze out of the reservoir after the end cap is completely tightened, you did not fill the reservoir with enough oil. If this is the case, you'll need to remove the cap and add more oil to the reservoir.

Clean the excess oil from the outside of the shock and then reinstall the spring and spring retainer. Your shock is now ready for installation.