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I have a Specialized Switch Hitter I have used for several years on both Presta and Schrader valves. Recently, my wife tried to inflate her tubes (Schrader valve) and could not get the pump to function. When I tried on my Presta valves, I experienced the same odd behavior she did, namely:

  • The handle requires too much force to depress when the chuck is on the valve.
  • The inline gauge registers a constant zero.
  • The valve is letting air out. I can let air out of the tube easily by bleeding off pressure using the little release valve on the handle.
  • When the chuck is not engaged with a valve, I can pump normally. I can't keep my finger on the chuck to build up any pressure, but air is definitely coming out.

I managed to partially fix the problem by disassembling the head and reassembling it, but now the inline pressure gauge is stuck at 60 psi even if I put enough air into it to get a tire to 130 psi. Does anybody know what might cause this problem?

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    I disassembled the head and put it back together, and it worked. I still have no idea what was wrong. – Dwindlehop Aug 18 '13 at 1:23
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    I had my Topeak floor pump fail in June. On inspection, the pin that secures the chuck lever had slipped out of one end of the chuck body, allowing the lever to be cockeyed. Unfortunately this resulted in damage to the gaskets (since I tried at least a dozen times to get it to work, each time abrading the center seal), and I had to replace the chuck. – Daniel R Hicks Aug 18 '13 at 2:38
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    @Dwindlehop suggest you move your comment to an answer, then mark your answer as "the" answer. That's site etiquette, it also makes it more clear that you solved your problem already. – PeteH Aug 18 '13 at 10:58
  • @PeteH The fact is the issue is not completely fixed. Last I used the pump the gauge was stuck at about 60 psi. I put enough air into it to pump my tires to 130 psi or so, but the gauge barely wavered. I still need to figure out what needs replacing on this pump. – Dwindlehop Sep 5 '13 at 17:29
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    I would guess that some particle of something has gotten wedged into the pressure gauge. About the only likely "fix" is to tap on it from various angles and see if you can dislodge whatever's in there. – Daniel R Hicks Sep 6 '13 at 15:32
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Considering it's supposed to be sealed you can get quite a lot of muck in a pressure gauge -- maybe dirt collected on the valve. That's probably what's causing your gauge to stick. The cause of the initial head jamming may have been similar.

I lost a tyre to a blowout when the gauge on my Road Morph was very reluctant to go up. I took the gauge to bits (one rather subtle screw/cap which also allows me to set the zero point) and cleaned the spring, the piston and the scale that shows through the window. I didn't oil/grease anything, as the piston felt like it hadn't been greased to start with. It seems to move freely now.

  • I know this is old but the comments helped point me in the right direction more than the existing answer. Especially @DanielRHicks's comment though in my case had options beyond just tapping it and hoping. – Chris H May 26 '17 at 8:52
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I've got a Specialized pump that's starting to do the exact same thing. Although there is a possibility that something simple could be going wrong with our pumps, the most likely explanation is that they have gotten some good use out of them over the years and as a result, they have worn out. Nothing lasts forever, especially not if it's got bushings, rubber seals and o-rings. I manage to extend the life of my pumps by oiling the seals, preferably with mineral oil as this tends to inflate the rubber seals a bit, but when something is worn out, it's worn out and simply needs replacing. You could rebuild your pump, but only if you can find a kit with all the parts you need, but there's no guarantee that would work like new. I'm planning on getting a new pump here pretty quick, you should probably do the same, it's a simple matter of life cycle replacement, count it as a regular maintenance expense.

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