im doing somthing wrong, why wont my pump work?

[jmattsen]

i have done two batches of homebrew test now and the firsttime i thought i just had a crap filter or somthing but after the second time when it did the same thing i know i have to be doing somthing wrong. i am using a mightyvac hand pump hooked directly to a milipore stericup and unless i constantly pump it, it loses pressure in a matter of seconds. i have tried everything i can think of to makesure it has a perfect seal but nothing helps. if i unhook the filter and just put my finger over the tube it will suction on to it so i know it isnot the pumps fault.

what could i be doing wrong?! i have one more filter left but with the ammount of hassle it was lasttime i am tempted to just go buy some syringe filters and not deal with the constant pumping again

 

[Abuckeye]

Use some plumbers putty, play do, or something similar where the top and bottom come together. Apply it from the outside after they have been assembled together. I've never tried it but I've seen and heard of people using it because the cups don't seal very well.