A recent investigation into another radiator failure identified the top port on my radiator was making contact with the radiator hanger. A situation I felt may contribute to fatigue and premature failure of the radiators. Each radiator has failed in exactly the same location, next to where the contact occurs, thus a reasonable assumption.
Given I've experienced multiple failures, I decided enough was enough and took matters into my own hands. I decided to eliminate potential contact by increasing the gap between the port and hanger. To do this I redrilled the chassis mount and hanger, then cut the top off both. Doing this increased the clearance by about 12mm, so ample clearance.
With careful planning, the process went well and was stress-free.
The following video illustrates the steps I went through to achieve the end result. You'll notice from the stills I used a Dremel to round the edges of the hanger and chassis mount, restoring a factory look. I also painted both to protect from corrosion and again give a factory look.
Do I feel the modification is the end of the radiator failures? Sadly not!
I've had a chance to investigate the cause further following our return from the Taffia Fish n Chip run. I've found the chassis bracket which was making contact transmits very little vibration, however, a significant amount of vibration is transmitted through the top hose itself. The strength of that vibration, particularly at tick over is concerning. I'm considering that to be a likely contributor to premature failure.
Having sought input from fellow 420R owners I've also discovered Caterham Cars recently revised the top hose to one with thinner walls. The reason for the change is unknown, could it be to help improve the failure rate by reducing the level of vibration?
Given this, I'm considering fabricating a replacing hose using a combination of silicon hose parts or even sourcing a custom bespoke hose. The theory being, a silicon hose will be much softer and thus reduce the level of vibration. Plenty to think about then!
Thanks for reading, please check back soon to see how things are going.
Agree about the radiator issue.
I am on my 3rd.
First was most definitely caused by the top hose being too short, as it was a brand new car a little disappointed.
New hose and radiator, lasted 6,000 miles but the leak has started again.
I think the curve on the top hose that I have is not sufficient to bypass the oil catcher, which we have to drain by syphon because we can't get the cap off, top hose is in the way.
Plan is to take the radiator off and a guy local to me who has done work for me before to modify the angle of the top and bottom outlet.
Hopefully this will mean both hoses…