It's probably just me - way too old for video games but....
I am stuck trying to get the oil dog in order to trade it for an umbrella.
I have the plunger gun & it's assembled. The oil can is in the right place next to the ledge with the dog. Pushing the oil button on the control panel eventually gets the dog to come & lick at the oil. I can get back down to the ground while the dog/oil are still there.
So what's your problem? The problem is that the robot won't take the gun (with the plunger in it). He stands next to the bollard at the edge of the wall & just shakes his head no. Tried everything that I can think of but his answer is always No.
I'm posting this here under issues just in case it is an issue - other than my stupidity 
Mod Comment: Moved your question here to Q&A FROM "issues" - and no, you're not stupid, just a bit rusty at solving puzzles. 
