Ive read a few threads about the improvement on the stock rear shocks by changing the factory oil to 10 wt oil.
My question is has anyone used a MityVac to do this? Seams one could pump the old oil out and refill with quality 10 wt oil using a MityVac....

Anyone done it? Pictures? I've never used one....

Stock 2012 shocks suck big time!

 

I used a air hose to drain oil out. I measured what came out and replace it with the same amount. You will have to force the new oil in and I dont think the Mighty Vac is packing enough *** to get it in. I used a large syringe I bought from Souther States and rigged a fitting to screw into the shock.

 

Screw in a brass barbed fitting into the shock and use any type of vacuum pump that has a reservoir to catch the fluid to pull it out then attach a syringe to the barbed fitting to force it back in.

Place the shock upside down to pull the fluid out and right side up to fill.

I've seen between 8 to 12 ounces of fluid in shocks but I always fill with 10 ounces.

 

I changed mine last year to 10 wt. I made a jig out of some scrap 2x4's. used a 1/8th barbed fitting with poly tubing. Bolted the shock upside down and pumped the old oil into a container. Close to 11 oz's came out. Reversed the shock and used Amsoil 10 wt shock therapy oil. Now I ride solo with 10 PSI and it feels great. I also changed my fork oil to SE Oil. It stopped the front end dive.

 

You can drain and fill the shocks with a vacuum pump, it's surprisingly simple.

Put the shock in a vise upside down with a barb type adapter fitting screwed nto the hole for the air hose and vacuum the oil out, no need to pump the shock. Use the cup on the vacuum pump to measure how much oil comes out so you put back in the same amount. You'll fill the cup about 3 times.

When it's time to fill the shock put it in the vise right side up. Inside the cap for the cup for the vacuum pump is a short nipple. Connect a piece of tubing long enough to reach the bottom of the cup. Fill the cup with oil. Connect the pump to the shock and pump. You will create a vacuum but no fluid moves. Then press the vacuum relese button and when the vacuum is released the oil will flow from the cup into the shock.

Below is a picture I stole from another forum showing how you plumb the pump to fill the shock. The cup that you put your new oil into is not installed on the pump so you can see the hose you install on the inside of the cap.

I used this process last month and it took maybe 15 minutes per shock to drain and refill.

 

Thanks all...

 

X2 (applause) for the idea of using the MightVac. I just completed mine this weekend ($42 for the MightyVac at O'Rielly Auto). Sucked the old oil out and did the tube to the bottom of the bottle trick to install the new 10wt oil. It actually took longer to remove and install the shocks than to replace the oil. And it rides 1000x better.

 

Not sure if you want to try but, on my 03 glide i simply set my shop air pressure regulator to 5 psi, held shock upside down and blew into air fitting. When I removed the blow gun the oil blew out. Did it a couple times to get all out, was quick and easy. Thought hardest part was getting oil back in until I found a meat injector found in my wife's kitchen drawers to refill. Measured out into her measuring cup and pulled into injector and placed large needle in air fitting to add to shock.

 

Is there a specific thread type I need to get for the fitting? Or is there just one type of 1/8 npt fitting?

 

Take the air hose fitting out of the shock and with you to the hardware store.