How to waterproof these electrical outlets?

I am using these electrical outputs to lead my motor cables out of the electric compartments. I tested them today with a bike pump and soap water. They leak like crazy. I guess they are only splash proof. Now I am thinking about filling them with sealant from the inside. Any advice for the right chemical? (Some kind of Sikaflex…)

I just screwed in mine very thight and they are completely waterproof!

It looks like you may have got some that are too big for the wires. I have used plenty of those and never had any issues.

Same as @Jezza, I use these for work generally and have on a few marine applications - looks like incorrect size.

Just make sure you tighten everything as tight as you can, use spanners or vice grips or whatever, esp on the one to the box

I Put in WiFi Kamera with some lamp to identify the origin for leakage; cable or shaft. Looked like this.

Thats funny! Im afraid it will be to late when I see it.

Drop a link for the ones you purchased. I’ll take a look and see if they the wrong size. When I tighten mine the little rubber seal pops right out they get so tight!

How much pressure you pump inside the case ?
No leak at 0.3bar should be good enough

Generic from China. I had 3 different sizes and always chose the one that just about fitted through.

I used a bike pump. No idea, will measure next time.