So I got a desolding pump yesterday. The kind with the plunger and the button. I used it on a couple of circuits and it has already lost a ton of it's original suction. Is there anything that can be done to get some of that suction power back again, or is this thing just a piece of junk?

 

These pumps has to be maintained like all sorts of equipment. If you dismantle it and clean it up it will work again. Be careful with oil. It is poison then it come to soldering.

 

Push the plunger down hard to displace the tip (unless it unscrews). pull the tip and attached cap off and clean out the accumulated crud. Check the bore of the tip for solder.

Some solder suckers work better and longer than others. In most cases, you will need some braid to wick up remaining solder to completely free the component.

 

I opened mine up. What is the greasy stuff that's in there? Would vasolene work as a replacement after I clean it?

 

It's probably a silicone grease to maintain the seal for the plunger. Too much will just trap dirt and solder bits. A thin film of vaseline might work.

To see if some is necessary, pop the plunger while holding the tip against your finger. If it takes some time to extend out, the seal is probably good enough to pull solder off a PCB.

 

I used to use just a straw for a solder sucker, but that gets hard on the lungs.

 

Real men heat the joint and then rap the board sharply on the tabletop to knock the solder off.

 

I have one of those rubber desoldering pumps. You can remove the tip from the rubber and dump out the dried solder. Those desoldering braid strips work great also, they just run out fast.

 

You don't have to pull it apart much. Put a (small!) drop of oil in the hole (after you cocked the plunger) then press the button so it sucks the oil in and atomises it. Then work the plunger a couple of times. Doing that anytime it gets slow normally keeps them running pretty good and helps to release the dead solder out the tip too.

 

If the seal is real rubber then petroleum (vaseline or motor oil) will destroy it. Use silicone oil.
My metal solder sucker is about 30 years old and still works perfectly. I never replaced the seals.

 

I prefer the small metal type too, mine is late '70's like yours. Is yours blue? The smaller plastic ones are ok too, but I hate the big soldapult brand they jump about way too much when they go off.

I think they must be silicone o-rings standard, we used a number of types of sucker when i had TV repair shops and used 2 types of motor oil (which was always on hand for lubricating some VCR mechanisms). I've never seen an o-ring fail from lubricant, including frequent use of WD40 to lube the suckers if there was no oil handy, and WD40 is largely kerosine. The couple of o-rings I have seen replaced were from dry use and got chewed from abrasion from solder stuck on the sidewall.

 

If the seal is real rubber then petroleum (vaseline or motor oil) will destroy it. Use silicone oil.
My metal solder sucker is about 30 years old and still works perfectly. I never replaced the seals.

Where would I get silicon oil, because the plunger is rubber?

 

The same place you get o-rings and seals, the local bearing shop.