how to keep pump chuck from blowing off valve stem?

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Catagory6
Posts: 612
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

chuck blows off smooth shaft valve stem around 80psi
have to hold it down with my toes while i continue to pump
this is getting kind of awkward


by Weenie


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AJS914
Posts: 5397
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

Get a new gasket. Don't use the new gasket on threaded valves as they will ream out the gasket.

Is this a Silca head?

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silvalis
Posts: 765
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

Time to get a new pump.
Chasse patate

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

I bought a 10-pack of pump heads for like 3usd. You fit them to most pump hoses. After 4 years of pumping 5 bikes/vehicles (many on latex tubes). I'm still on the first head. Works perfectly.

Seems only the head that came with the pump was crap.

Marin
Posts: 4035
Joined: Wed Jan 22, 2014 11:48 am
Location: Vienna Austria

by Marin

New gasket.

BTW; for SKS, a new head is actually easier to find and ridiculously cheap.

jfranci3
Posts: 1572
Joined: Tue Jul 26, 2016 5:21 pm

by jfranci3

Get a new pump head (chuck). Unscrew/Cut off the old one, jam or screw the new one on. https://amzn.to/2HeqPNj https://amzn.to/2KHtAch

bremerradkurier
Posts: 419
Joined: Mon Jun 13, 2016 4:18 pm

by bremerradkurier

On my '80s vintage Silca floor pump, I removed the pump head from the hose, got a piece of velcro strap from a fabric store, cut a strip about 12"/30cm long with a hole punched for the pump head valve stem. I could then press the strap ends together over the tire to hold the head on the tube valve.

AJS914
Posts: 5397
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

If you have an old Silca pump with the black gasket, get the new red 242 gasket. It's a huge improvement.

https://silca.cc/products/silca-242-gas ... sta-chucks

Here's the other thing I learned about Silca pumps/gaskets after using one for 30+ years. You aren't supposed to smash the chuck all the way down onto the valve stem. It should just sit on top. The narrow part of the valve pokes through and the wider part of the valve stem perfectly mates to the inner curve of the gasket. If you poke it all the way through you start reaming out your gasket, especially with threaded valves. The other way to go is just to replace your gasket every 2-3 years and not worry about technique.

I also only buy Michelin Airstop tubes with smooth valve stems.

Catagory6
Posts: 612
Joined: Thu Feb 09, 2017 2:36 am

by Catagory6

thanks for the tips
i just wrapped a rubber band around the chuck and rim/tire to hold it on

cheers


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JKolmo
Posts: 654
Joined: Sat Feb 10, 2007 2:00 pm

by JKolmo

+1. Get a Hirame head or a Silca Hiro, big improvement and if used properly won’t slip off!

mikemelbrooks
Posts: 345
Joined: Wed Jun 16, 2010 10:58 pm

by mikemelbrooks

AJS914 wrote:
Mon Aug 19, 2019 4:31 pm
If you have an old Silca pump with the black gasket, get the new red 242 gasket. It's a huge improvement.

https://silca.cc/products/silca-242-gas ... sta-chucks

Here's the other thing I learned about Silca pumps/gaskets after using one for 30+ years. You aren't supposed to smash the chuck all the way down onto the valve stem. It should just sit on top. The narrow part of the valve pokes through and the wider part of the valve stem perfectly mates to the inner curve of the gasket. If you poke it all the way through you start reaming out your gasket, especially with threaded valves. The other way to go is just to replace your gasket every 2-3 years and not worry about technique.

I also only buy Michelin Airstop tubes with smooth valve stems.
When my Silca pump finally gave out after 30+ years I cut the chuck off before throwing the rest away, I guess now it going on my new pump. Thanks

by Weenie


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