Leak on radiator bleed

jonathan_dyane · Post by **jonathan_dyane** » Sun Dec 28, 2008 2:23 am

Splashing out on a new radiator cap had now had the effect of forcing coolant to leak from the bleed point at the top of the rad. It appears to have two O rings which are intended to seal it which have hardened; has anyone replaced these with normal O rings before? I am somewhat reluctant to try and prise them off for experimentation in case they split and my plan fails, leaving me immobile..

CitroXim · Post by **CitroXim** » Sun Dec 28, 2008 8:10 am

Ordinary O rings should be fine Johnathan. I fully understand your reluctance to prise one off in case the inevitable happens.. You know it will

Our local Halfrauds do kits of assorted O rings and if you procure one, hopefully it'll contain what you need.

The only areas I'd be wary of using these general-purpose O rings is where LHM or diesel is involved.

DavidRutherford · Post by **DavidRutherford** » Sun Dec 28, 2008 8:22 am

This is part of the reason I tend to run most of my diesel vehicles with little or no cooling system pressure. Massive leaks become mere dribbles, to be fixed when I can be bothered. Hoses no longer swell, and the cooling system is no longer a scalding danger.

After all, the only reason cooling systems were ever pressurised was to increase the boiling temperature, so that petrol engines running at 95+ centigrade didn't boil their systems, and had a margin of overheat before there was any problems. Given that the XUD runs at about 80ish, I don't see there's any problems with running at barely above atmospheric pressure. The "too late lamp" is on below 100c, so if your coolant is boiling, the engine is most likely scrap anyway.

jonathan_dyane · Post by **jonathan_dyane** » Sun Dec 28, 2008 6:32 pm

Well, my immediate (temporary) solution was to paste the thing with a little blue hylomar and replace the original tired cap, but I must confess I had never given much thought as to the benefits of running zero pressure, my last TZD did blow coolant out of the expansion tank when running at high speeds which I put down to the cap, but then I did end up having to replace the HG... Perhaps though, once I replace the O rings, I will neglect to replace the new cap

I don't usually patronise halfrauds, but looking at their website does show some rather handy O ring sets, so perhaps I will swing by tomorrow...

Thanks guys.