Radiator and Heater Hoses - Mick's Tips of the Trade

By: Mick McCrudden

Date: 05.01.2018

Why is it we always forget to do the simple things? Uncle Mick gets into your hoses

When was the last time you had a good feel of your radiator and heater hoses?

A lot of people forget about them, until they give up! If you’re heading off on a long trip it can pay to drop down to the local parts supplier and grab some spares, just to have them there. It at least gives you a fighting chance to get rolling again if something fails.

There’s a chance your nearest country town won’t have them, so it’s a lot easier to have them on board. Don’t worry too much about what brand you’re buying. Do it through an auto store and you should be fine.

Simple things to check before you go away: look for your radiator and heater hoses and give them a visual check. Look around the hose clamps. Old hoses swell up in this area – it’s often fluid getting into the material and it’s only a matter of time before it fails. Another area to check is around any bends. That’s where the fluid is flowing quickest and it takes its toll.

Feel along the hose and give it a squeeze. You should get a consistent resistance all the way along. If there’s a soft area, that is a sign of trouble.

While you’re doing the squeeze test, you’re looking for something pretty pliable – check it against a new hose. What sometimes happens is you will get a build-up of shale on the inner surface, and this will come across as feeling stiff. You may even feel or hear that inner shale cracking as you go along. Yep, it’s time for a change.

Now while you’re in there, have a look at the overflow bottle for the radiator – if it has one. A lot of people believe that should be filled to its highest point, and that’s a fallacy. Don’t do it. It should be at its lowest point. Being fully sealed, it puts liquid into the overflow as it expands with heat.

If you overdo it, there’s a risk it will overfill as the engine warms up and get to the point where it overfills and siphons out the coolant. Not a good look.

Pretty much the same principles apply to checking both heater and radiator hoses, though the latter are obviously a smaller diameter. Remember to look for both the fill and return heater hoses.

One thing when you’re installing new gear, avoid the temptation to over-tighten the clamps, or you risk cutting into the very material you’re trying to save. Really they need to be just firm enough to hold everything in place, not to hold the whole car together!

So get under that bonnet and have a good feel around – it will do you good!

Mick owns Glenlyon Motors, an expert workshop and car storage facility in Brunswick, Melbourne. Call him on (03) 9380 5082.

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