How to use a tyre repair kit

There’s never a good time for your car to suffer a puncture. If you walk out to your car first thing in the morning to find it sitting on a flat tyre, or you’re driving along and hear the dreaded “bang, hiss, whadump, whadump, whadump”, you’ll probably expect your day’s timetable to come to a shuddering halt.

While punctures are common — they’re the second most frequent reason why motorists call out breakdown services — they don’t have to leave you stranded because you may be able to use a puncture repair kit to make your car driveable again. 

What happens if I get a puncture?

In the past, you’d have been able to reach into your car’s boot, dig out the spare wheel and jack, and replace the wheel at the roadside, but that’s no longer possible, because most car makers have replaced spare wheels with tyre repair kits. 

One reason for this is that a spare tyre, jack and tyre wrench can weigh up to 30kg, and replacing them with a far lighter repair kit helps car makers reduce weight, which in turn improves fuel economy and reduces CO2 emissions. 

There are two main types of puncture repair kit: one that uses an air compressor to fill the tyre with sealant, and another that simply comprises a pressurised can of foam and a hose to attach to the valve. Our guide will explain how to use both. 

How to use a puncture repair kit

Before you even think about getting everything you need out of the boot to fix a puncture, there are a few things you need to do first in the name of safety.

First make sure your car is in a place where you can safely walk around it without being too close to passing traffic. Then check that the handbrake is fully applied and the car is in first gear if it’s a manual, and in Park if it’s an auto. Turn on the hazard warning lights and then, if you have a warning triangle, walk 50 metres down the road behind the car and place it at the side of the road to let traffic know that your vehicle is stranded further along the road.

Next, inspect the tyre to find out where the puncture is and how big it is. This is crucial to whether you can use a repair kit to get you going.

The damage must be within the main tread of the tyre, and the hole must be no more than 6mm across. If the area is on the shoulder of the tyre, and if it’s bigger than 6mm, then the kit won’t work.

Your next task is largely dependent on the specific kit that your car has, because some ask you to roll the car so that the damaged area is at the top of the tyre, while others claim to perform better if the damage is near the bottom. Check your own kit carefully to see which it requires.

Compressor puncture repair kit

This is the most common tyre repair system that’s provided as standard on most new cars. It has four main elements: a container of tyre sealant, an air compressor with a built-in tyre pressure gauge, one attachment to join these two together, and another to connect the whole set-up to the tyre valve.

When using this type of sealant, it’s essential that you don’t remove anything, such as a screw or nail, that’s in the tyre and has caused the puncture, because doing so could damage the tyre further or create a hole that is too big for the sealant to plug. It’s also worth finding out what the correct pressure for your tyre should be. This information is usually found either on a sticker on the inside of the fuel flap or on the driver’s door pillar. 

There is usually a set of rudimentary instructions on a sticker attached to the side of the sealant can or compressor. It’s worth checking this to see if you need to shake the sealant can before using it. 

Once you’ve connected the compressor and tyre sealant to each other, remove the dust cap from the tyre valve and connect one end of the other hose to the compressor and the other onto the valve.

Then plug the compressor into your car’s 12-volt power socket, and let it run until the tyre reaches the correct pressure.

Using tyre foam to repair a puncture 

If your car doesn’t have a compressor type kit, it may have a can of tyre foam. This works in a very similar way to a compressor kit, but without the compressor. 

It consists of a can of foam and a hose, which is screwed onto the top of the can and directly onto the tyre valve. Once it's connected, you need to remove the protective tab surrounding the activation button, and press the button. Foam and air will enter the tyre at the same time, sealing it and reinflating it.

There is no tyre pressure gauge, so you need to judge when you think the tyre has been sufficiently inflated. If you have a tyre pressure gauge you can check it afterwards, or you can use one at a fuel station. 

With this type of kit, it is even more important to get the tyre fixed or replaced as soon as possible because having one incorrectly inflated tyre can seriously hamper a car’s handling and ability to brake. 

Get your tyre fixed as soon as possible 

Once the tyre is sealed and reinflated, pack away the kit and replace the tyre valve dust cover. Then you should drive straight to a tyre repair outlet, at a maximum of 30mph if you’ve used foam, or 50mph if you’ve used sealant.

Let the staff there know you’ve filled the tyre with sealant, because if the damage is repairable, it can be simply washed out once the tyre is removed from the wheel.

Once that has been done, you’ll need to replace the container of sealant, so make your local car parts outlet your next stop.

FAQs

Can a puncture repair kit permanently fix a puncture?

Definitely not. A tyre repair kit should only be used to get you moving again so you can drive to your nearest tyre retailer to have the problem fixed permanently.

How many times can I use a puncture repair kit?

If your car has a compressor puncture repair kit you can re-use the compressor and hoses multiple times. However, the can of sealant, whether it is a latex or foam one, that comes with a tyre repair kit cannot be re-used, it should be recycled and replaced after every use.  

How much does a puncture repair kit cost?

A can of tyre foam will typically cost between £10 and £20, while a container of latex tyre sealant will typically cost between £20 and £30. If you want to invest in a repair kit that comes with a compressor, you’ll usually have to pay £40 to £50.

Is a puncture repair kit the same as tyre foam?

Not quite, although they are similar in ultimate operation and effect. A repair kit will come with an air compressor to force the sealant and air into the tyre, while a can of tyre foam is filled with compressed air and foam, so it does not have a separate compressor.

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