New Radiator Fitted 2 .....Son of new radiator
Posted: Wed May 14, 2008 2:25 pm
Hi
Just by way of information and thanks to those who helped, we've fitted the new radiator, as mentioned, run it, next day cold bled it by removing the degass tank cap and the bleed hose plug, and as Aethelric did, we used a clear container with coolant in, and see-saw-ed it with the engine running for a few moments only. We then went on a 20 Km run. Next day we repeated the cold bleed and a longer run....no bubbles on both occasions, so the first bleed had worked. We went on another run today, and a long one tomorrow. On the assumption that any air still in the system after the first bleed would find it's way to the highest point after a run , namely the head, we cold bled (twice) , to check up. Now, presuming that the system is working as it should with a new radiator, we managed to get the bottom hose warm for the initial bleed, proving that the stat had opened, but on subsequent runs of around 18 Km. in either direction, the TM2 read as normal, increasing quite a bit in 30mph. zones, and through town driving slowly. When first stopped in town, Tony checked the bottom hose....stone cold. After starting in town, while the engine had been just sitting, it obviously got quite hot....started up, and the circulating coolant soon lowered the head temperature on TM2.We returned home, again stone cold bottom hose. A similar length journey today over some very dodgy pot-holed roads where we were driving more erratically, with the engine heating more, and the bottom hose was just comfortably warm.
I post this to show that the discussions on cooling have pretty much said what we had noted regarding the water circulating through the top half of the system until a slight strain is put on the system, when the bottom half cuts in. What is interesting, though, is that the fans for the radiator only function at comparatively lower indicated temperatures when the air con. is on, and they don't operate until much higher temperatures when the air-con is off...obviously to cool the air con. heat exchanger/rad. Perhaps, as some folk have said that they have only heard the radiator fans cut in just before a major overheat, then the system is designed to leave the air con. on all year, and just change the temperature setting (manual air con.). ...Any thoughts?
Cheers
Helen
Just by way of information and thanks to those who helped, we've fitted the new radiator, as mentioned, run it, next day cold bled it by removing the degass tank cap and the bleed hose plug, and as Aethelric did, we used a clear container with coolant in, and see-saw-ed it with the engine running for a few moments only. We then went on a 20 Km run. Next day we repeated the cold bleed and a longer run....no bubbles on both occasions, so the first bleed had worked. We went on another run today, and a long one tomorrow. On the assumption that any air still in the system after the first bleed would find it's way to the highest point after a run , namely the head, we cold bled (twice) , to check up. Now, presuming that the system is working as it should with a new radiator, we managed to get the bottom hose warm for the initial bleed, proving that the stat had opened, but on subsequent runs of around 18 Km. in either direction, the TM2 read as normal, increasing quite a bit in 30mph. zones, and through town driving slowly. When first stopped in town, Tony checked the bottom hose....stone cold. After starting in town, while the engine had been just sitting, it obviously got quite hot....started up, and the circulating coolant soon lowered the head temperature on TM2.We returned home, again stone cold bottom hose. A similar length journey today over some very dodgy pot-holed roads where we were driving more erratically, with the engine heating more, and the bottom hose was just comfortably warm.
I post this to show that the discussions on cooling have pretty much said what we had noted regarding the water circulating through the top half of the system until a slight strain is put on the system, when the bottom half cuts in. What is interesting, though, is that the fans for the radiator only function at comparatively lower indicated temperatures when the air con. is on, and they don't operate until much higher temperatures when the air-con is off...obviously to cool the air con. heat exchanger/rad. Perhaps, as some folk have said that they have only heard the radiator fans cut in just before a major overheat, then the system is designed to leave the air con. on all year, and just change the temperature setting (manual air con.). ...Any thoughts?
Cheers
Helen
I found a broken fan when I changed mine 
You are geting the same results that I did, I know where most of the coolant flows and I am begining to understand where the problems come from. 
