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Pump not pumping up enough pressure....why?(9 posts)

Pump not pumping up enough pressure....why?TheJoker
Sep 1, 2003 4:35 PM
I have a Silca Super Presta pump, and that little right angled thing for pumping up disc wheels. Unfortunately the people at Silca didn't think some people might want to use both the disc and normal adaptors. So, to switch between them you have to take the hose and hose-clamp-thing off. So I haven't bothered to put the hose-clamp-thing back on for the disc adaptor.

Anywaaaaay. I can only seem to get up about 80psi max with this pump on either wheel [disc or normal]. The pump is rated at 250psi or something like that, so that's not the problem...

I'm undoing the valve lock pretty much all the way. Is this right? If not please don't laugh?

Am I missing something? Is the disc adaptor useless, or is the pump, or am I?

Does anyone use the Silca disc adaptor? Does it work?

I hate you Silca Adaptor!!! Die!!!
Someone else has to hold itSprint-Nick
Sep 1, 2003 4:46 PM
I know your pain! The adaptor will have the tendency to move off at an angle so its not straight over the valve which will allow air to slowly leak. To prevent this you need to to either have someone else hold the adaptor on while you pump (easy) or try to hold it on with one hand (can be hard)... holding with one hand tends to be a pain when the pressure gets high though since you can't pump very hard.

Hope this helps!

Cheers,
Nick
Someone else has to hold itTheJoker
Sep 1, 2003 4:53 PM
I've tried this Nick. I know what you mean, there's no way you can do it without someone holding it, or doing it with 1 hand. But even with this I still can't get the pressure. The pump and tyre are rated at over 200psi. There is NO way anyone could get this pump to pump up to that pressure. I'm sure it's leaking out somewhere, but I can't think where. Maybe the poxy little adaptor is leaking it out....

Can you feel my rage?
Someone else has to hold itTheJoker
Sep 1, 2003 4:57 PM
By the way Nick; do you have the same adaptor, and what pump?

what sort of psi can you get up?
Maybe...dave_w
Sep 1, 2003 5:05 PM
I have the same adapter. The rubber donut inside wears and the hole enlarges over time. They are cheap and easy to find. Alternately, the "front" part of that chuck screws on and off to replace the donut and it might have just backed off a little which will also cause the symptoms you are having.
That might be your answerSprint-Nick
Sep 1, 2003 8:31 PM
I'm not sure if I have the same adaptor as you but the pipes (adaptors) I've used have always been pretty similar. I've gotten about 180 into a rear disc with them when someone holds it so Dave might be right.

Cheers,
Nick
If it's leaking from the pump head you should hear the hiss.dzrider
Sep 2, 2003 5:35 AM
If you don't, I'd suggest taking the pump shaft out and making sure that the leather piece at the end seals well against the sides of the pump's shaft. I've had to spread that piece out (twice in 16 years) because I wasn't getting adequate pressure.
Re-install the hose clamp?MisJG
Sep 2, 2003 5:51 AM
I am not familiar with the set-up you refer to, but if I read your post correctly you state, "I haven't bothered to put the hose-clamp-thing back on for the disc adaptor". Does the hose-clamp-thing attach the hose to the chuck? If so, and it's not attached, there's your leak! How can you expect something to work properly if it's not assembled correctly?
Re-install the hose clamp?TheJoker
Sep 2, 2003 9:16 AM
You could be right. I had to cut off the old one [stupid design] so I'll need to get a new one. But that could be the problem...