Any (without TPMS) - Valve Core Replacement

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Fri 3 Mar 2017 15:18
Any (without TPMS) - Valve Core Replacement - edlithgow

I suppose this is elementary, but I've never encountered it before.

Local petrol station compressor has been broken for over a year , so I've been topping up with a hand pump. I now have 2 tyres (one motorbike, one car) that no longer accept air, though when I got the mc to a compressor it would, presumably because of the higher pressure.

I'm thinking I should probably replace the valve cores. Never done it, but I note Halfords do a 4 in 1 tool.

www.halfords.com/workshop-tools/garage-equipment/b...l

GF is in the UK now so I could probably get her to bring one back. Perhaps valve cores too, though I should be able to get them here.

Am I missing anything?

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Fri 3 Mar 2017 15:53
Any (without TPMS) - Valve Core Replacement - RobJP

My first thought would be that the fault lies with the hand pump.

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Fri 3 Mar 2017 18:44
Any (without TPMS) - Valve Core Replacement - liammcl

yup,
bet it doesn't have a pin in the middle, or a long enough one
to depress the pin in the valve...

Cheers
Liam

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Sat 4 Mar 2017 00:21
Any (without TPMS) - Valve Core Replacement - edlithgow

My first thought would be that the fault lies with the hand pump.

Well it's only affecting two tyres at the moment, and it worked on all of them initially.

Could be wear and manufacturing tolerances on both, I suppose, but I don't see how it can be just the pump.

I tried bleeding some air out, thinking it might blow out some muck, but I just ended up with a flatter tyre.

I wouldn't put mineral oil grease on a tyre valve since it might attack rubber, but I suppose silicone might be OK.

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Sat 4 Mar 2017 00:33
Any (without TPMS) - Valve Core Replacement - liammcl

the valve itself screws in, maybe on the two tyres it is screwed in lower than the hand pump's middle pin can depress in....
on the other two the valve may be higher up, allowing the pin to push the plunger down.

on the machine , it may have a longer plunger , which works all on all 4.

Anywho, new valves will reveal all, or the tool will allow the existng valves to unscrew a bit upwards.
you can tell by pressing the middle pin of the tyre valve in,
with a little screwdriver, pen tip etc, and see if it's working ok, or a difference in height

Cheers
Liam
ps www.ebay.co.uk/sch/i.html?_from=R40&_sacat=0&a...5

Edited by liammcl on 04/03/2017 at 00:44

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Fri 3 Mar 2017 16:33
Any (without TPMS) - Valve Core Replacement - Brit_in_Germany

Try greasing them.

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Fri 3 Mar 2017 18:14
Any (without TPMS) - Valve Core Replacement - liammcl

I have that tool, (from ebay)
after the local tyre place changed a tyre and next day it was flat.

Changed the valve with the tool , simples

i103.photobucket.com/albums/m147/liammcl_2006/110_...g

there are videos on using a rubber tyre valve to refil aerosol cans... I tried twice with mixed results..

www.youtube.com/watch?v=KWIL_jhk-y8

On my push bikes, which don't use a Schrader valve
I have to let air out of them , before they will refil.
trying to pump pressure in won't work , unless there is a biggish difference between what's in the tyre and what I am trying to pump in..

Daft as it sounds, let some air out, and I bet it'll refil by hand pump.

or the hand pump , may not be pressing the middle pin of the valve, in enough

Cheers
Liam

Edited by liammcl on 03/03/2017 at 18:30

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Fri 3 Mar 2017 18:32
Any (without TPMS) - Valve Core Replacement - daveyjp
My cheapie pen style pressure gauge has a cap which is also a valve core remover.
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Fri 3 Mar 2017 18:42
Any (without TPMS) - Valve Core Replacement - liammcl

ps for info for anyone inetrested
this is what a valve looks like

the pin at the bottom is what you see when looking into the tyre's valve
i103.photobucket.com/albums/m147/liammcl_2006/110_...g


normally it is shut...(the pin is at the bottom of the pic)
i103.photobucket.com/albums/m147/liammcl_2006/110_...g

and it has to be pushed in , by the thing filling it...
i103.photobucket.com/albums/m147/liammcl_2006/110_...g
otherwise it wont fill....

Cheers
Liam

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Sat 4 Mar 2017 11:43
Any (without TPMS) - Valve Core Replacement - Cyd

Probably not a bad idea since the opportunity arises.

Believe it or not I use one of these for both our bikes and cars.

www.halfords.com/cycling/bike-maintenance/bike-pum...e

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Sun 5 Mar 2017 02:38
Any (without TPMS) - Valve Core Replacement - edlithgow

My Lada tool kit had a similar "stirrup pump". Worked quite well.

You can get something similar here but the quality generally isn't great and they don't seem to last long. In particular, the lever-chuck (?) attachment to the valve tends to be unreliable.

I now use one of these. Low capacity but it screws on so seems to be more secure, and it has an adapter for Presta bike valves too.

www.decathlon.co.uk/classic-hand-pump-id_8210716.h...l

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Sun 5 Mar 2017 02:46
Any (without TPMS) - Valve Core Replacement - edlithgow

So far I've managed to avoid TPMS, and I'll try to continue to do so in the future for as long as I possibly can, but apparently:-

"If the vehicle is equipped with TPMS you must use Nickel plated valve cores to prevent corrosion in the stem. A lot of tire change monkeys remove the cores to make it easier to inflate the new tires and throw the cores somewhere on the machine along with a dozen more, when they pick it up again it could be any one of them and if its a brass one you could have a problem down the road.

These nickel plated ones can be identified by their red band and they are also fine to use in a normal stem. "

I came across an article a while ago that argued that the jury was now "in" on nitrogen tyre (well, tire in this context) filling because it tended to protect fragile TPMS sensors from oxidation damage.

So if N was a solution looking for a problem, as many have argued, now they've found it one.

Huzzah! (Well, Yee-ha in this context)

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Sun 5 Mar 2017 13:04
Any (without TPMS) - Valve Core Replacement - skidpan

Not all TPMS systems use special valves. Some have no extra fitments in the wheel at all and the readings are taken from the ABS sensors. Had 4 cars like that and only one with the special valves.

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Sun 5 Mar 2017 13:12
Any (without TPMS) - Valve Core Replacement - gordonbennet

Normal tyre valves don't need the centre depressing to fill with air, but you need a fair shove of pressure to open the valve against the spring, though they obviously need the pin depressing to release air.

Its much easier to fit a valve with one of these

www.tyrebaydirect.com/56-Tyre_Fitting_Tools/228-Pl...l

than it is with a 4 in one multi tool, espacially if you're fighting against air pressure having seated the bead without the valve centre inserted.

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