Replace Weller Desoldering Pump Tip - Page 1
Forum section: electronics / general

author: labarowski
author_rank: Contributor
timestamp: August 09, 2013, 01:00:38 am
content: I've got a Weller 7874B desoldering pump. It's a pretty generic design and I'm fairly certain that you can buy it under a bunch of different names. I was using it last night and some solder dried in the tip. I can't get all of it out (well, I could probably drill it out but I'd rather buy a new tip and be done). You seem to be able to buy replacement tips with and without the metal ring shownhere.I can buy replacement tips in bulk without the ring for a bit less, but I can't seem to figure out how to remove the current tip from the ring. There's a round bronze piece on the back of the ringthat has two slots it looks like you can fit a coin into. I tried putting a penny in and turning both directions but all I did was bend the penny ever so slightly. Does anyone have experience with this pump and know how to remove the teflon tip?

author: fpliuzzi
author_rank: Regular Contributor
timestamp: August 11, 2013, 03:52:10 pm
content: Hello,I have a similiar Radio Shack version of that desoldering tool that has the same removable slotted bronze tip retainer. As a test, I just unscrewed mine using the wide tip of a 12" long screw driver I had on hand.Maybe yours has become frozen together because of their use of dissimilar metals. You may be able to free up the bronze insert by heating the removed front assembly of the pump using a heat gun. The two metals should expand at different rates and they may break their bond.Alternately, If you unscrew the whole tip/metal ring assembly from the device, then push the plunger down and remove the big spring to fully expose the thin metal tip cleaner probe... can't you just turn the removed tip assembly around and try to push the solder blob out by going in with the probe from the front of the plastic tip, instead of from the rear? Does that work any better?Regards,Frank

author: labarowski
author_rank: Contributor
timestamp: August 16, 2013, 01:13:41 am
content: Thanks fpliuzzi. I think that I'll try to find a long screwdriver as well and get a bit more leverage. Will try a heat gun if that doesn't work. I was concerned it wasn't made to be removed and I didn't want to break it. Good to know it does come off.

author: fpliuzzi
author_rank: Regular Contributor
timestamp: August 16, 2013, 02:16:10 am
content: Your welcome. You may also be able to improve the suction of the device a little bit. Here's some info I posted elsewhere about tweaking these simple manual solder suckers..."When mine began to work poorly, I noticed that the o-ring on the plunger had shrunken. I lifted off the o-ring using a dental pick and wrapped a single layer of 24 gauge buss wire in the area where the o-ring sat to enlarge the diameter of that area a bit.Next, I filled that same area with plumber's silicone grease. I also coated the o-ring with the grease and re-installed it. The o-ring was now a slightly larger diameter and exhibited a tighter fit when I slid the plunger assembly back into the blue barrel. The suction was better on my unit after this."If by chance the plunger on your sucker seems to have a loose fit, maybe you can give this a try while you have your device apart.Regards,Frank

author: labarowski
author_rank: Contributor
timestamp: August 20, 2013, 03:15:35 am
content: I was able to get the tip out a couple days ago with a large screwdriver and vice. I'm going to hold of on improving the seal as the solder suck is pretty new and still has a good seal. The only reason I am replacing the tip is I let some solder harden inside and it just won't scrape off. I'll bookmark this page so I can find it when my solder suck has a few more miles behind it though. Thanks again for the advice.