Bleeding coolant system procedure

[Tom163]

Hi all,

I am going to have a go bleeding the cooling system just to rule out a hunch I have I just wanted to make sure I have the correct way first.

Take coolant tank cap off run the engine until up to full temp, then turn the heater on full hot...wait for the fan and once the fan stops switch off.

Or

Run the engine and use the red bleed screw on the lower rad hose? until a steady flow of coolant trickles out?

Car is a T4 if that makes a difference?

Thanks

[Tom163]

Also the coolant in this is green not the OAT orange stuff I usually get....is it genuine Volvo being that colour?

Thanks

[Tom163]

Anyone?

[Anadinolin]

i would not have the engine running while draining the system, there is normally a valve on the bottom of the radiator on the left hand side as you look at the car from the front.

my personal preference is:

drain till empty either on a cold or luke warm engine with the heater on full(not hot because the pressure traps steam etc and sudden pressure release while hot will allow air to get in and shock your block)

refill the engine with a cheap coolant or fave coolant, depending on how wealthy you are

run till hot with the heater on full and flush again once cool.

2 flushes should be ok as the old stuff dilutes down into the new stuff. provided you stick to the same stuff each time - there are cleaners out there for the cooling system of your car so i would stick that through aswell.

someone might come along with a similar technique to me

[GrahamBrown1]

the best way to bleed air form the system is run with the tank cap off, it wants to be at a fast idle tho more 1500, 2000 rpm for 10 mins so the coolant can get around the all of the system. the non turbo petrol engines have a comman issue of un even coolant levels, high one day low the next in the expansion tank. this is how you cure that problem

[Tom163]

Originally Posted by Anadinolin

i would not have the engine running while draining the system, there is normally a valve on the bottom of the radiator on the left hand side as you look at the car from the front.

my personal preference is:

drain till empty either on a cold or luke warm engine with the heater on full(not hot because the pressure traps steam etc and sudden pressure release while hot will allow air to get in and shock your block)

refill the engine with a cheap coolant or fave coolant, depending on how wealthy you are

run till hot with the heater on full and flush again once cool.

2 flushes should be ok as the old stuff dilutes down into the new stuff. provided you stick to the same stuff each time - there are cleaners out there for the cooling system of your car so i would stick that through aswell.

someone might come along with a similar technique to me

At the minute I am only bleeding the existing coolant dude but that very good guide will come in very handy in the future! thanks

Originally Posted by GrahamBrown1

the best way to bleed air form the system is run with the tank cap off, it wants to be at a fast idle tho more 1500, 2000 rpm for 10 mins so the coolant can get around the all of the system. the non turbo petrol engines have a comman issue of un even coolant levels, high one day low the next in the expansion tank. this is how you cure that problem

Thanks dude will have a go!