A tyre that repeatedly needs air should be checked, even if it never looks completely flat. “Slow puncture” describes a symptom, but the leak may come from the tyre, valve or wheel assembly. Recording the pressure loss and arranging a proper inspection is more useful than repeatedly topping it up or guessing where the air escapes.
If the tyre is visibly deflated, damaged or affecting the car's handling, stop using it and arrange assistance. A leak described as slow does not guarantee that it will stay slow.
Look for a repeatable pattern
Start with the correct vehicle pressure settings, a suitable gauge and comparable measuring conditions. A reading after motorway driving cannot be compared directly with a cold morning reading as though nothing else has changed.
Record each tyre's measured pressure before adjustment. Note the date, units and whether the tyres were cold. The record is particularly useful when one corner repeatedly falls below its required setting while the others behave differently.
Do not choose an arbitrary loss rate that you consider acceptable. The significance depends on the tyre's starting pressure, the time involved, conditions and the vehicle's requirements. If you are uncertain whether the change is significant, ask a tyre professional to assess the record and assembly.
A leak is not always a nail in the tread
Michelin's flat-tyre guidance identifies several possible sources of pressure loss, including a puncture, sidewall damage, a leaking valve and the wheel. A visible object in the tread is useful evidence, but the absence of one does not rule out a leak.
| Area requiring assessment | Useful information to provide |
|---|---|
| Tread or sidewall | Visible object, cut, earlier repair or damage history |
| Valve area | Recent valve or sensor work, damage noticed during inflation |
| Tyre-to-wheel interface | Recent fitting, corrosion concerns or a previous sealing problem |
| Wheel itself | Pothole or kerb impact, visible deformation or a suspected crack |
These categories help explain what a fitter may examine. They are not a diagnosis from a photograph. Tell the workshop about all relevant work and symptoms instead of asking it to fix only the first possibility you have found online.
Preserve the evidence without making the damage worse
If an object appears embedded in the tyre, leave it for the professional to assess. Photograph it from a safe position, along with a wider view showing its location. Do not pull it out simply to see whether the tyre goes down faster.
Photograph the wheel and tyre before cleaning if you have noticed a suspect mark. Keep the previous invoice when the problem began soon after fitting or repair. A timeline is useful; it does not by itself prove that the previous work caused the leak.
There is no need to dismantle a wheel assembly at home to gather information. Do not crawl beneath a vehicle supported only by its emergency jack or loosen a sensor valve in search of a leak.
What to ask the tyre specialist
Explain the symptom first: which tyre, how often it needs air, the measurements and any warning or handling change. Ask for the source of the leak to be established and the tyre's condition assessed, including the consequences of any low-pressure driving.
Ask these questions before agreeing the next step:
- Where was the pressure loss found?
- Is there additional tyre or wheel damage?
- Is repair suitable for this particular damage and tyre?
- If replacement is needed, what specification and matching requirements apply?
- What checks should I make afterwards, and when should I return if the loss continues?
A repair decision follows inspection. A small visible hole does not reveal all internal damage, and a tyre that has been driven underinflated may need a different outcome from one stopped promptly.
When a wheel problem is suspected
Keep the tyre and wheel questions separate. Replacing a tyre will not resolve a crack in a wheel, while buying a wheel will not make an internally damaged tyre usable again.
Our guides to alloy-wheel corrosion and cracked alloy wheels explain the next questions when the wheel is implicated. If a replacement is recommended, contact Wheel City with the vehicle and existing wheel specification.
Keep checking after the work
Save the diagnosis and invoice with the earlier measurements. Follow the fitter's instructions for checking the pressure and completing any required monitoring-system procedure. If the same tyre loses air again, return with the record rather than assuming that a second reset will cure it.
A tyre-pressure warning light is an alert, not a leak detector that identifies every failed component. Manual measurements and a physical inspection remain important.
Frequently asked questions
Can I keep topping up a slow puncture?
Repeated top-ups are not a repair or an assurance of safety. Arrange an inspection and follow professional advice about whether the vehicle can be used.
Why does the tyre look normal?
Appearance alone is an unreliable pressure check. Use an appropriate gauge and the correct vehicle setting; a visibly normal tyre may still need attention.
Will a new valve definitely fix it?
Only if the valve is the relevant fault and the rest of the assembly is suitable for use. Confirm the leak source before replacing parts.