Changing stock shock oil, help! Won't compress (2024)

So looking over my rig I notice one of my shocks the bottom threaded part of the shock body came unscrewed and dumped all my oil out. I cleaned the entire shock up good and filled back up with 40wt oil and now it seems like it won't compress, it feels very hard to compress. Is there a certain trick to filling with oil or what? I extended the shock fully and filled about half way, let the bubbles pop, pushed the piston in some and filled the rest of the way and extended the piston back out and put the cap back on and now it won't compress.

Any help is appreciated

Basically what the others said. Your shock has a bit too much oil in it. When I fill my shocks, I generally pull the piston all the way down (fully extended) and fill the shock body until the oil is only about 1 cm from the top. Then, carefully, work the piston back and forth, which forces a lot of the air out of the oil and makes sure there isn't a little bubble down by the piston. You'll see a lot of tiny bubbles after doing this. Tap the side of the shock body with your finger a bunch of times to help them settle out. Then, once you're satisfied that there are no more bubbles below the piston, fully extended the shock and prop it up on something (or suspend it somehow) so it doesn't fall over and leave it for about 5 minutes with the cap off. This makes sure all the air is out of the oil and it is completely filled in the region below the piston. Once there are no bubbles left, compress the shock to somewhere near the middle of its travel and top the oil off carefully until it reaches the top of the shock body. Make sure your shock cap has the little rubber plunger piece installed and screw it on. Your oil should be topped off enough that some leaks out of the cap as you are screwing it on, ensuring that there isn't a little bubble at the very top of the shock.

Finally, you want to tune the oil level in the shock. After tightening the cap, check the way the shock works. Fully compress it. It should get a little stiff just as it reaches full compression, and then when released, it should extend by itself most of the way to full extension. If the shock gets stiff too early and extends by itself quickly to full extension, you've got too much oil. Loosen the shock cap a little bit and compress the shock a small amount until a little oil leaks out, then tighten the cap and re-check. If the shock easily goes to full compression and doesn't extend by itself very far when released, you need to remove the shock cap and top off the oil. When you do so, extend the shock a little bit further than you previously had when you topped it off (this allows more oil in the shock body). Really, you're looking for the correct amount of shock shaft extension when filling/topping off that essentially gives you the right amount of oil. The only other condition you want to check for is "dead spots" in the travel on the shock. If while you're checking the shock you feel that small portions of the travel become really easy to move, like the shock isn't really doing anything in those areas, it means you've got air in your oil and you need to remove the cap and work the piston more and let it sit for longer.