My Joe Blow has been faultless but now it pumps a bit of air in, but when pressures get above 25psi (ish) it stops putting air in and the pressure gauge doesn't work.
A google reveals lots of information on O rings.
I can find a small one in the piston head that looks okay - its on the mechanism that you can pull out - is this the one mentioned?
I can't work out how to get in the main shaft - anyone been successful in getting into this?
If I get in can i just slap some grease about?
Mine often packs up, so far just taking it apart, unscrewing it from the bottom of the stand and giving it a bit of a clean seems to work - not had to replace o rings yet - pile of old crap, not a patch on my rennkompressor
I recently had the same issue with my 10 year old JoeBlow PX. The O ring in the plunger is not available separately according to extra.co.uk. If you do need to replace it, it comes as part of a rebuild kit (TRK-JBP01 TPK REBUILD KIT - JOE BLOW PX/SPRINT RRP £3.99)
How do I get to the plunger?
turn the black plastic bit at the top a quarter turn. If you mean the seal on the end of the plunger then i don't think its in that kit. The rebuild kit DOES NOT have this in
the O ring has a weird chamfered profile also so not just a standard round one
[url= http://www.247cycleshop.com/shop/article_573/Rebuild-kit-for-Joe-Blow-PX-_-Sprint-Floor-Pumps.html?shop_param=cid%3D120%26aid%3D573%26 ]rebuild kit with O ring ?[/url]
Not sure what being describe above or how mine differ from the OP's but you get to he main plunger on mine by unscrewing the cap where the shaft enters the pump body.. couple of flats either side to allow purchase to unscrew.
I found a regular grease was all mine needed until the spring at the base of the unit rusted through. You get to it by removing the plate at the bottom of the unit. I found all I needed, plunger o-ring, new spring and 'valve' for the base all in the rebuild kit from SKS cycles (make sure you get the right kit for your pump).
box fish - as i said - the o ring is not round in profile, that one is, it doesn't work. Also states for PX & Sprint Floor Pumps (no mention of sport)
Sorry, wrong pump (mine is a PX).
[url= http://www.247cycleshop.com/shop/article_574/Rebuild-kit-for-Joe-Blow-Sport-floor-pump.html ]Rebuild kit for Joe Blow Sport. Looks like it contains an O ring (hopefully the right one)[/url]
Also worth checking the screw on cap opposite where the hose fits to the body, had those work loose and bleed off air a few times.
Mine failed about 3 years ago. Took me a while to find the problem which was a crack in the diaphragm of the pressure gauge. It was OK up to about 30psi then started hissing. Topeak sent a new gauge FOC though which was very kind.
Cheers all - a strip, clean and regrease seems to have worked.
Might get a service pack to keep it running.