How to maintain a desoldering pump at 2025

[Kiriakos GR]

There is no single or generic advice, of how to maintain a de-soldering pump.

I will agree that O-Ring over the piston, this needs lubrication.
Mostly because atmospheric-air along friction, both are known factors at removing life cycle from an O-Ring.

An O-Ring this is no designed to live for ever.
And therefore we can only delay the damage due aging and friction.

About the selection of lubricant, we need to consider first of what our desoldering pump this is made from.
And I am talking about the material of the cylinder this made of.

Best choice of all professionals, this is the Taiwanese desoldering pump, this is more expensive, due the fact that it cylinder this is made of aluminum.
And even the entire top section, this is also made of aluminum.
And so we end with two aluminum parts, which connect together by the regular nut and bold concept, and therefore its important even metal threads these to stay clean too.

My first choice of lubricant, this is regular grease mixed with 10-40 motor oil.
By this trick, the regular grease this is modified to liquid grease. 

Vaseline this has different properties, its a problematic material, because it viscosity changes rabidly according to room temperature.
At a cold environment, the pump will lose 35% of suction power.

At a soldering pump, with aluminum cylinder, body temperature this is directly transferred over the cylinder.
Within two or three minutes of time the temperature of the cylinder this is equal to our body temperature.
And at that point even by using Vaseline there is no much of a difference at pump performance.
But if you do require best pump performance by the first use, then you have to avoid Vaseline

When we use the ideal liquid grease, we run in to a new problem.
Our metallic cylinder alone this must be cleaned with a de-greaser chemical solution, or alternatively we need to use a fabric this passing thru the cylinder, along high pressure of air, so these low end threads to get cleaned from any debris.

Such a cleaning process it requires a minimum of 15 minutes.

For the cheap 100% made of plastic pumps, I do recommend just a few drops of 10-40 of motor oil as a lubricant.
Plain plastic cylinder this has higher friction than a aluminum cylinder, and pump performance this is poor.
The use of grease or Vaseline this will make things worse.

The same recommendation stands and for the oversized plastic pumps.
At the time of maintenance, the motor oil and any debris, both can be removed by the use of a toothbrush at both ends of the plastic cylinder.

Some desoldering pumps, appear having room for double O-Ring.
This is an illusion, because the main spring this is designed to handle the acceleration of a single O-Ring.
The Taiwanese desoldering pump, this it does work even with double O-Ring, but the benefit this is not significant.

Best advice when you get a NEW pump, remove the O-Ring and use it as an sample so to get thee spares from the local hardware store.
Then add a bit of grease over them and store then with in a nylon bag.

Silicon grease: industrial products does not come in small quantity, No-name products, unknown viscosity of a grease, all these are traps, that you may waste your cash for.
You better stay at the safe side, by using regular lubricants, which are widely available at your location.