Should A Shock Absorber Extend On Its Own? Shock Testing

Are you worried about your suspension? Is your vehicle driving different? Well, a great place to start troubleshooting is with your suspension. Your car or truck’s shock absorbers should extend on their own. But they can be fickle. Some extend very slowly appearing like they are stuck. When they are on your vehicle the weight of it will make this negligible.

Others are not designed to extend fully and you may be looking at them thinking, ” I bought some bum shocks.” But in reality, they are working just fine.

If you are not sure about how to go about checking your suspension then it is always recommended to take your vehicle to your trusted mechanic. Let them troubleshoot it with you there. Most mechanics will show you what they are looking for and will be happy to teach you about what is wrong. If not, then you should ask friends and family for a recommendation for a mechanic they trust.

Should A Shock Absorber Extend On Its Own?

Yes, shock absorbers extend on their own. If they do not they are defective. It is very important that shock absorbers have the tendency to extend naturally as this should be their natural position. Why is this their natural position?

A shock absorber is filled with gas. That gas is put there to minimize the movement of the absorber. This way the shock absorber will absorb the movement o the suspension when you travel over uneven terrain. This gas is compressed and has a natural pressure that extends the shock absorber. So, if a shock absorber does not extend on its own then there is an issue with it and it should most likely be replaced.

Monroe shocks states:

“Piston rods on low gas units can take up to 2 minutes to extend, while non-gas units will not extend on their own.”

A shock absorber is a device that is attached to the top of your vehicle’s frame and at the bottom of your vehicle’s suspension arm. Each wheel has its own shock absorber, and the shock absorbers are attached to each other by a pair of pistons. A shock absorber is simply a cylinder that slides up and down.


The piston is like a rowboat’s oar; it can’t be pulled through the water. It moves up and down in the cylinder, resisting oil pressure, which is sealed in by a spring. If the piston seal breaks or the oil gets out, the engine will need to be rebuilt.

The car that I have described is certainly not a comfortable one for the passengers to ride in, for it is liable to bob up and down and shake its passengers’ heads; it is also liable to cause shocks and rattles.

Should Shocks Rebound? Do Mine?

It is common to think, “Hey, I bought a new set of shocks from you, but one of them didn’t work”. This new shock has hydraulic action only in one direction.

Shock experts will tell you that it’s not uncommon for customers to be concerned when they first receive their new shocks. If you’re not sure about the condition of your shocks, it’s a great idea to talk to your service provider to find out if he or she can help you determine the cause of the problem.

It’s a good idea to check your shocks regularly to make sure that they are in good working order. Here’s the deal:

More than 85% of all cars are fitted with twin-tube shocks and struts are prone to failure. The fluid pressure inside the twin-tube shock and struts can build up to dangerous levels, resulting in a loss of control of the vehicle. To reduce the risk of this happening, you need to inflate the twin-tube shock and struts with nitrogen gas.

If you buy a coil-over assembly you can prime the strut with the spring attached. You will have to do this to attach the spring if you continually buy a spring and strut combo separately or if you like to lower your suspension using lowering springs. This is the best spring compressor I found and it’s available on Amazon.

The shock is designed so that it can be used in vertical as well as horizontal applications. The shock is installed vertically when the part is on the shelf and horizontally when the part is on the workbench.

As soon as the shock is released, the nitrogen in the reservoir will push back against the force of the shock, pushing the hydraulic fluid back to its original position. Hold the shock vertical and then stroke it to fully compress it, and then to fully extend it several times.


The first few times you drive your vehicle with the shock installed, you may experience a little bit of vibration. This is normal and should not be a problem. Once the shock has been installed and the vehicle has been driven for a while, the vibration should subside.

Is There A Break In Period For New Struts?

Yes, there is a break in time for new struts. You should expect about 2-4 hours depending on the weight of the vehicle and the design of the strut. After you drive your car or truck a few times the suspension should feel like it did when you first ought it assuming there are no other issues with your suspension. You should have a little bit of awkward handling for no more than 4 hours.

Here is a video of a mechanic with a custom-built strut compressor using a pneumatic gun to break in the bad boy. There are many cheap strut compressors readily available at Harbor Freight or Amazon. Take a look:

If it persists you should take your vehicle to the shop you bought the struts from and have them take a look and see if they installed the struts wrong, if they are the wrong size, or if there is another issue with your suspension.

It is much safer to find out at the auto shop than it is to find out passing slower cars on the freeway late for work with your kids in the car. Anything can happen.

Again, shock priming is not needed, but it is quick and easy and can help reduce the break-in period of your new shocks. If you are installing the shocks yourself then priming may be a good idea if you want to skip the breaking-in phase. Just have some patience if your car drives a bit funky for the first few days or so.

Thanks for reading and stay dirty