air in cooling system & the home made pressure tester FYI (1 Viewer)

Jan 12, 2016
well I had been scratching my head for a couple of weeks now as to why the overflow bottle was showing higher than normal levels after shutdown with little pressure in the hoses. - air was getting in

Tried a different radiator cap, couldnt see any leaks, just the level would go about an inch & half above the Full line when warm & some days stay at the full mark - I run it half way between low & full cold and 'normal' operating temp would see it at the full mark and when cold back down half way.
no visible leaks to be seen (red toyota coolant used)

I had redone the HG 3 years back so started worrying but this would only happen now & then over the last couple of weeks and when engine cold, coolant level was unchanged in the overflow - sitting at normal half way between low & full

we are in lockdown (Melbourne) so getting to a shop to buy a pressure tester was out of the question and then bingo, i had a thought !
The schrader valve on my mtb ripped from the tube and I thought, ill put it in the end of the overflow hose (exp tank end), secured with a clamp and used my MTB shock pump to pressurise the system a little.
Sure enough coolant started seeping from the seal where the top hose goes into the radiator upper tank at just over 13lb / 0.9bar (pump has a gauge reading in LB & Bar)

I count myself lucky to have caught it in time cause its not fun doing a HG

So, if you need a pressure tester, use a schader valve on the overflow hose - works a treat - but dont use a compressor !

new radiator ordered.......

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