desolder pump repair

I do not think so, but it could get stick if left alone. WD40 is not the best either, use a 3in1 type of oil, very little though.

my 2cents worth, Homer

I seem to recall years ago, using a tiny smear of washing up liquid on car brake cylinder seals, to get them to fit onto the pistons, and then go into the cylinders. I think it was one of those auto mechanics' trade tips. Those seals are synthetic neoprene I think, so probably immune to attack by most things. If the seals in your sucker are synthetic too, then I don't think you will have a problem. I agree that WD40 is probably not the best, but if the seal is rubber or a rubber derivative, then a mineral oil like 3 in 1 probably isn't very good either. I would have thought one of the modern synthetic engine oils, or even a vegetable based cooking oil, would be safest.

Arfa

No, introducing a non-perishing lubricant is a good idea IME, but I personally wouldn't want to use washing up liquid.

Probably not, but it may 'gum' up causing sticking or drag. It is likely to dry up fairly quickly because AFAIK washing up liquid is a water based substance.

I can only speak for the neoprene washer style pumps, not the o-ring seal variety-

I routinely apply a dollop of silicone grease (the clear lubricant stuff

*not* heatsink compound) to the barrel and piston of my solder suckers and it decreases friction, improves the seal and gives a huge performance in suction, even when the neoprene washer is already worn. It also drastically increases the life of the seal/washer, I haven't changed the neoprene washer in mine for ages.

The advantage of silicone grease is that it doesn't seem to affect the neoprene washer at all, whereas mineral oils I'd guess may cause it to disintegrate over time. I'm not sure if washing up liquid affects neoprene or rubber though, or whether the o-ring seal type pumps use synthetic or plain old rubber.

Dave

Ug. I'd be wary of introducing anything untested into a car's braking system. The correct thing for this is red rubber grease which you can get from a good motor accessory shop, etc. It comes in small tubes or tubs similar to general purpose grease, and is always useful for other apps - I keep a tub in the workshop.

--
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    Dave Plowman        dave@davenoise.co.uk           London SW
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I used to simply use brake fluid on the cylinder if it was sticking a bit. It was a tip I got from a mechanic, I don't know if it was a good one or not ;-)

Dave.