Table of contents
Introduction
The neoprene pump cup on a Coleman 286A Lantern failed to make a good seal. I could manually strech the cup to get it working for a few pumps, but then it wouldn’t pump correctly again. Canadian Tire sold Coleman replacements, but these were only leather rather than the original neoprene. Replacement pumps seemed to have the original neoprene, but forum posts online say that the leather is more reliable in the long run.
Replacing the Pump Cup
I followed Coen’s guide on how to install the leather pump cup. I soaked the leather cup in SAE 30 4-Cycle Lawnmower Engine oil overnight before installing. It was just the engine oil I had on hand.
After soaking the cup, I disassembled the old pump and installed the new cup using the parts from the replacement kit. Unfortunately the back-up plate/nut doesn’t seem to be reusable and could pose a problem in the future if discontinued.
Luckily unlike Coen, I was able to reinstall the plunger without needing a soda can funnel. The leather cup was flexible enough to squish in without much issue.
After a few test pumps, I was able to confirm that the pump was working correctly as the tank was pressurized.
Printing a New Knob
This lantern was intially used for parts, so it needed a replacement knob. After checking a manual online I was able to determine the part number was 288C1501 for a Valve Knob. Unfortunately, I couldn’t find any Canadian source for replacement parts. Since it was just a plastic part, I decided to print it myself. I couldn’t find any publicly available models online, so I decided to use Bryce’s DIY Knob to create my own knob.
I chose Knob Style 1 and the Round Insert. Both my V0 printers seemed to have issues with the thermistor (temperatures kept sporadically changing), so I printed the prototypes with my Switchwire.
I settled on the following dimensions: Knob Style 1:
- 1 Diameter (30 mm)
- 2 Height (8 mm)
- 3 KnobWidth (7.5 mm)
- 4 KnobHeight (10 mm)
- 5 InsertWidth (10.2 mm) - extra to account for ABS shrinkage
- 6 InsertDepth (6.5 mm)
- 7 PointerDepth (1 mm) - to remove the pointer I also ended up adding a hole to the middle of the knob so it could be screwed in.
Round Insert:
- 1 Diameter (6 mm)
- 2 GripLength (0.5 mm)
- 3 GripQuantity (13)
- 4 InsertWidth (10 mm)
- 5 InsertDepth (6 mm)
My 0.4 mm nozzle on the Switchwire wasn’t able to print small enough for the teeth on the insert, so it ended up being a press fit without the screw. The insert is small enough that if it did break, it’s easy to print a replacement.
Files below:
Conclusion
With the new knob and pump cup, the lantern was good to go. I also installed a steel mesh globe by Woods (Canadian Tire’s house brand). It won’t crack like the glass versions and it hasn’t seemed to have impacted the lantern’s functionality (the lantern doesn’t blow out). It actually might cool down faster too.
