Trouble with vacuum seal

[Event_Horizon]

I have a SomaErect STF VED, medical grade with 3 cylinders. I would like to do the 3 cylinder protocol.

I started with the A tube, with I think sufficient lube on both the penis head and tube, and I pumped standing. I used the large insert.

With each pump, the shaft seems to expand forward a little bit but then retracts to its original position.

Is there a way to check that I'm getting a seal? I'm holding it fairly tightly against my pelvis, but I'm worried about the bottom of the tube as that is against loose scrotal skin.

Should the cylinders fog up if I have a proper seal? I don't see this happening.

Finally, do I have to shave in order to get a seal? I have not done that yet. Would more lube on the insert help?

I know many of these questions have been answered before, but I'm struggling to sift through all of the info. Sorry for so many posts, and thank you.

[Nolte94]

You have to be shaved, yes.

[Mikel7]

Yes you should be shaved and you should definitely pull the scrotal skin out and away from being pulled inside of the tube. It is normal for the tube to fog up - for me I apply heat while using a VED and this steams things up a bit.

[Event_Horizon]

Thank you both Nolte94 and mikel7. I tried it today after shaving and managed to get a response. I think there's more I need to learn, but I'll search around. I had a tiny slightly red discoloration on the glans afterwards, which made me concerned about over-pumping. I did 3 pumps on one go with Cylinder B, with 10 second pauses, and 4 pumps on another go in Cylinder A, also with 10 second pauses.

Should they be rapid pumps? Like 1,2,3,4,5 pumps, hold for 10 seconds, release? Or 1, hold for 10s, 2, hold for 10s, 3, hold for 10s, release button?

Your replies meant a lot and helped a lot too. Thank you again.

[Mikel7]

I pause in between each pump and wait for between 10 to 30 seconds. For me if I pump to fast there can be slight pain. I also have a pressure gauge with mine so as to not over pump. I have a couple LeLuv cylinders with a vacuum gauge.