A while back I posted about removing the top water branch without disturbing the other head nuts. Glad to report that following helpful advice from this forum, the job has now been completed successfully and the joint is leak-free. I used a new branch from Seven Workshop, no gasket but sealed only with grey Loctite 5660 (which appears to have replaced 5699). This was allowed to squeeze out slightly, then cured for 24 hours before torquing up the two nuts to 20 ft lb.

Spurred on by this, I also replaced the side water branch which needed a helicoil on one stud as the original was finger tight ! This job is just possible in situ but the oil filler gets in the way and it wasn't keen to unscrew.

I then reconditioned a spare Ruby radiator, using soft solder on several tiny pinholes plus some epoxy on a couple of inaccessible places. Testing required sealing the stubs with winemaker's corks and pressurising to 3 PSI with a bicycle pump via a scrap schrader valve whilst watching for streams of bubbles in the bath. After multiple mends and tests I was finally rewarded with a radiator which would hold 3 PSI all day.

To complete the job, new upper and lower hoses were fitted and I now have a completely leak-free system.

A couple of points to note, although the coolant drained out was clean, there was a fair collection of rust flakes between numbers 3 and 4 cylinders revealed when the side branch was removed. These have accumulated in the 10 years or so since the last clean-out. Being the sort of person I am, I measured the antifreeze mixture needed to refill to within an inch of the top of the header tank and it came to 9.5 pints.

Location: New Forest

On the subject of anti freeze, are any of the modern variants detrimental to anything in an A7?

Location: Shropshire

For those inspired by Johns work, a suitable tank for the radiator can be a problem. Can take the wife a while to polish the scratches out of the bath. I made a rough wooden frame and lined with a plastic sheet. The radiator under slight pressure resembled a giant Alcaselzor tablet!

Here an antifreeze type A is commonly marketed but also a less expensive inhibitor only Type B which I have always used on older cars. It is claimed to have a specific heat nearer water and so superior to antifreeze, except that b.p not elevated, and of course no frost protection. Motors always treated remain like new inside.

My RP lost a lot of water under braking (Girlings! A tiny drilling in the cap would send water 3 feet in the air; even assuming an unlikely 1G stop, just how sufficient pressure was generated I am not sure.) A simple catch container (please not plastic) can gather lost gold for regular return.

Location: Auckland, NZ