Burping or bleeding coolant system

[fanvol]

Have just replaced the coolant on my v70 but can't find a way to burping the system to remove trapped air. There is clearly air inside traped as I have removed 5 litres but just managed to put back 4 litres. Any advise here would be great. I been looking for a radiator cap but I can not find. Car is a 2002 v70 auto petrol.

[Clan]

Originally Posted by fanvol

Have just replaced the coolant on my v70 but can't find a way to burping the system to remove trapped air. There is clearly air inside traped as I have removed 5 litres but just managed to put back 4 litres. Any advise here would be great. I been looking for a radiator cap but I can not find. Car is a 2002 v70 auto petrol.

all you have to do is drive it a few miles to full temperature , let it cool and top up , no problems with air on these cars ...

[cheshired5]

Originally Posted by fanvol

Have just replaced the coolant on my v70

The cooling system is 8 litres so if you've only drained 5 litres, you haven't replaced the coolant.

As above ref: bleeding. No special procedure.

[petey]

Originally Posted by Clan

all you have to do is drive it a few miles to full temperature , let it cool and top up , no problems with air on these cars ...

If it were me, and I was suspicious of an issue, I wouldn't drive the car and confirm it, I would work very hard to get as much air out as I could. You could easily have a small bit of corrosion break free and jam the jiggle-pin in the thermostat, the way to find that is not to load the engine on the hottest week of the decade.

Best practice is, as stated elsewhere, to run the car with the cap removed so that it burps it way free of air. If you want to leave the cap on because Volvos don't have a problem, do so, but bear in mind the cap will only release air when that air is under pressure. If air is trapped anywhere it will fail to remove heat from whatever is nearest it and if that happens to be somewhere serious, you will have a failure long before you reach the break pressure of the cap.

[fanvol]

Originally Posted by petey

If it were me, and I was suspicious of an issue, I wouldn't drive the car and confirm it, I would work very hard to get as much air out as I could. You could easily have a small bit of corrosion break free and jam the jiggle-pin in the thermostat, the way to find that is not to load the engine on the hottest week of the decade.

Best practice is, as stated elsewhere, to run the car with the cap removed so that it burps it way free of air. If you want to leave the cap on because Volvos don't have a problem, do so, but bear in mind the cap will only release air when that air is under pressure. If air is trapped anywhere it will fail to remove heat from whatever is nearest it and if that happens to be somewhere serious, you will have a failure long before you reach the break pressure of the cap.

Ok I run the car for a while and it has burped I pressed few times the the upper radiator hose the one in S shape and there was a leak an small crack on the hose. I went inside the car and temperature was at maximum in must been for one minute or less strange as i was observing temp all the time and it was way below sundelly for few seconds it went all the way up. I switch off the car imediatly. I have ordered the upper radiator hose and will collect in 1 hour at my local shop to have this replaced. Car will be off and parked until this is sorted hopefully nothing got got damaged with overheath. A message was saying engine overheated look user manual. I aware I have replaced just half of coolant. I used prestone redy to use or 50/50. The original one was a green one which was there since i bought the car no idea but looks green as the volvo one. any advise here how to take this forward very appreciated.

[cheshired5]

For the time it takes to do an incomplete coolant change, I would either do it properly first time or leave it.

Oh and never use premix for a coolant change as your system mix will be guaranteed wrong every time.

[fanvol]

Originally Posted by cheshired5

For the time it takes to do an incomplete coolant change, I would either do it properly first time or leave it.

Oh and never use premix for a coolant change as your system mix will be guaranteed wrong every time.

sorry. what is wrong with pre mixed coolant? is the mix proportion 50/50 that prestone states not real?

[cheshired5]

Originally Posted by fanvol

sorry. what is wrong with pre mixed coolant? is the mix proportion 50/50 that prestone states not real?

The Prestone is 50/50 but you still have 3 litres of old coolant left in your cooling system which doesn't have the properties of 50/50 so will dilute the effectiveness of the new and mean your cooling system does not contain a clean and fresh 50/50 mix.
That's the whole point of a coolant change otherwise it's not really worth the time or effort.

[petey]

If you have any doubt about the mix of coolant to water, get hold of a Hydrometer, and this will measure the specific gravity of the liquid in the cooling system and thus tell you the ratio you have.
https://www.halfords.com/motoring/en...eze-tester-meg

Echoing earlier comments, it is strange how people rarely find the time to do something properly, but instead end up finding the time to do it twice.

[Brendan W]

I replaced the original coolant in mine after 9 years with Volvo and really didn't need to. I had decided it needed doing before measuring the concentration and the inhibitor effectiveness. Lesson learned. Fit the genuine stuff and forget.