Tilley X410A first fire up

Without all the hardware does the pump tube look like this?

 

Yes, mine looks the same, it can get a measurement of the thread length if you like.

 

It might sound mad but have you turned the pump nut over and tried it that way? There might be a slight recess that allows it to screw down further?

on second thoughts looking at your pictures even that might not be enough

Yes, new seals first I find, otherwise i end up chasing my tail

a photo of your without the parts might help to compare??

 

I will get some better photos tomorrow and take it apart.
Has me a bit baffled, but definitely looks like there is too much thread for the end to screw down onto.
At first I thought that there may have been gunk in the threads but appears OK.
There is a bit of rubbish in the pump tube however, looks like a gold paint/grease.
I'm assuming this is wear from the brass inside the pump? It's still well oiled and feels lubricated.

 

Ok

I had another look at your photos and it’s hard to tell from here.. you have it there so you can see straight away
But I thought in this pic maybe it wasn’t screwed down far enough? I could still see threads?

 

The are two ways air can escape from where you show in the image you posted above.

1) Most probable, the filler cap seal is NOT O.K.
Remedy - fit a new washer!

2) Possible but unlikely, the threads at the top of the pump tube are damaged making it difficult to screw down the pump clamp firmly.

See following -

Without the rubber seal and the "metal cup washer", the pump clamp should screw all the way down like this, if it doesn't, get the threads sorted.



With rubber and metal cup washer in place, screw the pump clamp down as far as it will go


Insert pump plunger and tighten plunger guide

Assuming the pump has been screwed firmly into the tank - you will notice that when removing the pump, the clamp nut (large knurled nut) will turn (from my personal experience) between 0.5 and 2.5 turns before the pump starts to unscrew. This is to release gently any pressure from the tank without getting your hand sprayed with kero as is usual with other types of Tilley pump - see the following:

Notice the kerosene spraying small hole in the "fixed" pump clamp ( 239 pump from an R1 heater) on the left and no hole on the "floating" pump clamp nut (2557 pump on the right).

 

I took that photo to show the range of movement, that is the position it would appear after unscrewing the pump out of the lamp.

Yes a new washer will sort the leaks.
From looking at your photos, it appears that there is something wrong with the end cap/threads, I can screw the pump clamp down with or without the washer quite happily, its the end cap that is not screwing down enough from what I can tell, there is a good 3mm thread still visible between the end cap and the pump clamp.
I havent counted the turns, but I can say it feels forever to unscrew the pump, I will take it apart so you can see inside the end cap.
To me, it appears there is not enough thread inside the cap for it to even screw right down, so this is what has me stumped.

 

It's not supposed to screw right down for the reason I gave in my previous post.

Here are images of two examples of the pump plunger guide, they are both 4.9mm deep with (as best as I can measure) 2.63mm of thread. Hopefully you can see that although the thread doesn't go the full depth, the remaining distance is machined out so the guide will screw the full 4.9mm onto the pump tube :-



The top side:

 

Yes I understand the reasons given, but my visible gap is much wider than yours, the threads look the same as your photo, there must be something thats clogged up the thread in the cap.
None of my tilley lamps have any thread visible but the cap will do a turn or two as you describe to release the pressure before the pump unscrews.

Might need to put it in the ultrasonic cleaner.

 

I've given it an ultrasonic clean and installed a new washer. My guide cap measures 4.9mm deep also, and the thread about 2.8mm deep.
However it doesn't appear to be machined out like yours, I can see where the pump tube has been trying to cut the thread into the tube further. It was hard to photograph but that confirms the problems I'm having. Probably not too big a deal, but its the first time I've encountered this.
Probably just cosmetic more than anything seeing the thread visible, it looked like something was out.
It takes about 3 and a bit turns to wind the nut out before the tube will unscrew.
Looks like this thing has had a ton of use.
Look at all the brass dust that's turned to gunk inside the pump.
The guide appears heavily worn too.