Radiator bleeding

[pallet30]

Does anyone know how to bleed a radiator without a bleed screw?
I'm having issues with the firenza again and I believe it has an air lock in the cooling system. Any suggestions would be appreciated.

[ChrisT]

Just jack the front up, or park on a slope, so the rad cap is the highest point in the system, take cap off, leave it running and let gravity do the job.
Unless you've got a boxer engine in there, in which case ignore the above advice.

[gtviva]

these don't normally give any problems with bleeding/air locks, is the thermostat OK? and the original stat used to have a little ball float for just this reason to let the air out before the stat opened, the other problem can be the by pass pipe from the water pump to the back of the head very common for that to get blocked

[froggy]

Make yourself a burping bottle with a plastic bottle closest to the rad filler neck and a rag to make a seal

[iamgroot]

I'm with froggy on that, we had a chevy pickup that we couldnt get rid of the airlocks, regardless of slope we parked it on or anything else, we used a water bottle from an office water dispenser with a radiator hose slid onto the end and poked into the radiator cap upended with a hosepipe poked through a hole in the "bottom" the water is forced into the cooling system by the weight of the water in the bottle and the air is pushed up and out through the water in the bottle never to return

[retromadness123]

Second that with froggy had a similar issue with a Peugeot 306 and used the same method and it worked

[Deleted]

fit an overflow bottle, fill bottle half full of coolant, fill rad full, start car get up to temp of stat opening keeping the radiator as full as possible, revving engine as few times can shift air bubbles and will allow you to see the flow through top of rad confirming pump is good. Make sure heater is in hot position if on a water control valve. when you think you have all the air out fit rad cap and allow to cool completely, as it cools and the coolant contracts it will suck coolant back to rad from overflow, now repeat the warm up routine but with cap on and allow to cool again, keep the level in the overflow bottle at about half way. The idea is as the air rises to top of rad it is vented out into the overflow bottle where you will see it bubble through the coolant. When it cools again any air expelled when hot is replaced with coolant. How many people fill a rad brim full, engine gets hot, water from overflow pipe to floor and they are happy next time they check level and it is down in rad but at same position it always is i.e. it finds it own level. The problem here is you now have a large volume of air in your coolant system that increases cavitation through pump and a coolant/air mix does not cool any where near as good as pure coolant, you will never get all air out but you can give it the best chance by fitting an overflow bottle. When you have run the engine up to temp and cooled down several times you can check you coolant level by marking the overflow bottle in the hot and cold level positions. if it ever changes from these two positions then you have a coolant system problem.