Bike pump pressure gauge repair



B

BillX

Guest
I have a pump dating back to around 85 that has a built in pressure
gauge that's been working great until a couple weeks ago. For some
reason the gauge now reads 5-10 lbs when not in use. Is there a way to
fix or recalibrate? It looks like there are some access screws
surrounding the gauge housing.
 
W

Werehatrack

Guest
On 4 Jun 2006 16:10:39 -0700, "BillX" <[email protected]> wrote:

>I have a pump dating back to around 85 that has a built in pressure
>gauge that's been working great until a couple weeks ago. For some
>reason the gauge now reads 5-10 lbs when not in use. Is there a way to
>fix or recalibrate? It looks like there are some access screws
>surrounding the gauge housing.


Check with the manufacturer, if you can identify who made it. Without
their support in making parts available, I suspect that the answer is
going to be "no". Most tire pressure guages have no provision for
calibration via any user-adjustable feature. (In fact, none of the
ones I've had could be recalibrated.)
--
Typoes are a feature, not a bug.
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Words processed in a facility that contains nuts.
 
K

Kenny

Guest
BillX wrote:
> I have a pump dating back to around 85 that has a built in pressure
> gauge that's been working great until a couple weeks ago. For some
> reason the gauge now reads 5-10 lbs when not in use. Is there a way to
> fix or recalibrate? It looks like there are some access screws
> surrounding the gauge housing.


You might give it a go by using a digital pressure gauge made by
topeak. Pump up your tire to whatever desired psi using your old pump.
Check what the pressure gauge reads. Take another reading using the
digital pressure gauge. You may not ever be able to get your old pump
gauge to read properly but at least you'll know how much it's off by.
May be a little overkill as the digital pressure gauge is around $20.
But hey, if you've grown emotionally attached to your 21 year old pump
why not?

http://tinyurl.com/0
 
J

john

Guest
BillX wrote:
> I have a pump dating back to around 85 that has a built in pressure
> gauge that's been working great until a couple weeks ago. For some
> reason the gauge now reads 5-10 lbs when not in use. Is there a way to
> fix or recalibrate? It looks like there are some access screws
> surrounding the gauge housing.


This is a floor pump? W/ a round pressure gauge? If so, numerous air
pressure gauges are available from people like Enco & McMaster-Carr.
I'm fairly certain you can find one to fit your needs. It doesn't have
to be bicycle specific, & it will probably be cheaper. While you have
it apart, you might want to clean & lube the check valve, too.

Regards, John
 
A

Andrew Price

Guest
On 4 Jun 2006 19:40:45 -0700, "Kenny" <[email protected]> wrote:

>You might give it a go by using a digital pressure gauge made by
>topeak.


I've been thinking about buying exactly that - are you pleased with
it?
 
B

BillX

Guest
john wrote:
> BillX wrote:
> > I have a pump dating back to around 85 that has a built in pressure
> > gauge that's been working great until a couple weeks ago. For some
> > reason the gauge now reads 5-10 lbs when not in use. Is there a way to
> > fix or recalibrate? It looks like there are some access screws
> > surrounding the gauge housing.

>
> This is a floor pump? W/ a round pressure gauge? If so, numerous air
> pressure gauges are available from people like Enco & McMaster-Carr.
> I'm fairly certain you can find one to fit your needs. It doesn't have
> to be bicycle specific, & it will probably be cheaper. While you have
> it apart, you might want to clean & lube the check valve, too.
>
> Regards, John


Yes, it's a floor pump with a round gauge. Think I'll start with
someone's suggestion to measure if the gauge is always off by the same
amount first and just correct in my head if that's the case. Otherwise
I'll check out your solution. Thanks.
 
Bill Brunning writes:

> I have a pump dating back to around 85 that has a built in pressure
> gauge that's been working great until a couple weeks ago. For some
> reason the gauge now reads 5-10 lbs when not in use. Is there a way
> to fix or recalibrate? It looks like there are some access screws
> surrounding the gauge housing.


This usually occurs when someone fails to knock free (or even unscrew)
a Presta valve when inflating a tire. In that event, initial pressure
to open the valve can greatly exceed 200psi and stretch the Bourdon
tube (that uncurls to give pressure readings).

http://tinyurl.com/z4unj

A common fix for this is to lift the pressure indicator needle from
its shaft (this is a press fit) and put it back in the shaft
positioned at zero. Most of these gauges are still reasonably linear
with as little yield as 5-10 psi.

Jobst Brandt