Kykdaar
Grey Hound
- Joined
- Sep 14, 2007
- Messages
- 7,610
- Reaction score
- 1
- Location
- Wingate Park - Pretoria
- Bike
- Zundapp (all models)
Whilst prepping a F650 recently I noticed that -
1. The fan came on pretty quickly (95 degrees)
2. Shortly after the cap's relief valve would open under pressure and release coolant into the reservoir bottle.
3. If the reservoir bottle was previously filled to the indicated MAX mark, the coolant would now rise above that and spill out of the top of the reservoir bottle.
4. On cooling down the coolant would be sucked from the reservoir bottle back into the radiator and the level in the reservoir bottle will drop to the indicated MIN level.
Given that the system was properly bled, to me the above indicated that the coolant is heating up to quickly which, if I understand things correctly, relates to a pressure problem as coolant that is kept under pressure has a higher boiling point.
So I fitted a new radiator cap and now the picture changed completely -
1. The bike had to stand and idle for a much longer period before the fan kicked in.
2. Once the fan was running, there was no transfer of coolant to the reservoir tank like in the past - it seems that the fan and the radiator cap was now in balance keeping the heat of the coolant constant.
So ja, one amazing mechanical device.
1. The fan came on pretty quickly (95 degrees)
2. Shortly after the cap's relief valve would open under pressure and release coolant into the reservoir bottle.
3. If the reservoir bottle was previously filled to the indicated MAX mark, the coolant would now rise above that and spill out of the top of the reservoir bottle.
4. On cooling down the coolant would be sucked from the reservoir bottle back into the radiator and the level in the reservoir bottle will drop to the indicated MIN level.
Given that the system was properly bled, to me the above indicated that the coolant is heating up to quickly which, if I understand things correctly, relates to a pressure problem as coolant that is kept under pressure has a higher boiling point.
So I fitted a new radiator cap and now the picture changed completely -
1. The bike had to stand and idle for a much longer period before the fan kicked in.
2. Once the fan was running, there was no transfer of coolant to the reservoir tank like in the past - it seems that the fan and the radiator cap was now in balance keeping the heat of the coolant constant.
So ja, one amazing mechanical device.
