Loosing air

gbr236
gbr236 Posts: 393
edited October 2013 in MTB workshop & tech
I hope you can help a roadie sort out a new mtg for his son.
The fork is brand new and will not hold air.
Proper shock pump but forks looses pressure over about half an hour.
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I have read a lot about valve cores leaking. Is this most likely cause?
Should I under the nut at the top (marked preload) or the much smaller nut which appears to be holding the valve in place?

Its a mail order and Id like to get sorted asap.

Thanks

T

Comments

  • 97th choice
    97th choice Posts: 2,222
    How much pressure does it lose, all of it?
    Too-ra-loo-ra, too-ra-loo-rye, aye

    Giant Trance
    Radon ZR 27.5 Race
    Btwin Alur700
    Merida CX500
  • gbr236
    gbr236 Posts: 393
    Yes fraid so
  • kajjal
    kajjal Posts: 3,380
    I would contact the retailer and explain the problem. They should then take a look and replace if needed.
  • gbr236
    gbr236 Posts: 393
    Will do
    I know thats the right thing to do, but the boy wanted to ride tomorrow....
  • coulddobetter
    coulddobetter Posts: 812
    Difficult as under warranty. But a schrader valve removal tool and new schrader valve wouldn't cost much . Motor factors I found cheaper than bike shop. Be aware that each time you check air is lost via pump hose .
    Do not undo either of the 2 nuts you refer to it would be obvious you had done so and could void warranty and they are not what you want to change the valve. Schrader valve tool just slots over the valve itself loosen anticlockwise and tighten clockwise
    If you do decide to change the valve don't overtighten.

    Had air loss on a fork and replaced all seals and valves. If I remember rightly tool and valve was about £3.00
  • The Rookie
    The Rookie Posts: 27,812
    Just to be clear, the valve unscrews from inside the tube you attach to the pump to, using the flats you can see just either side of the central pip.

    As hinted at, what suggests it is losing air, every time you connect the pump you'll drop about 10% of the pressure you saw before last removing the pump.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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