Ruby radiator

[Tiger]

just about to fit the radiator.
Any advice to check for blockage and leaks before fitting?
Regard
          Tim

[John Cornforth]

Whilst repairing my Ruby radiator, I came up with this method to find and pinpoint small leaks.  Block the inlet and outlet stubs with tapered winemaker's corks, plus a turn or two of plumber's PTFE tape to help seal. Seal the radiator cap with a rubber insert disc cut from an old inner tube (it ought to have a seal in normal use anyway). Attach a rubber tube to the overflow pipe and pressurise the rad to about 1 PSI with a bicycle pump.  With the rad laid flat in a bath of cold water, any leaks show as a stream of bubbles. Or multiple streams in my case !

A simpler leak test would be just to block the stubs, prop the rad vertically and fill with water to nearly the top of the header tank. A heat gun is useful to quickly dry off any spills whilst filling.  Then watch for damp patches.

John Cornforth

[Chris KC]

I'd certainly suggested hosing it through in both directions to shift any loose stuff before it goes on the car. If you feel it needs de-scaling it's better done off the car in my view as it's difficult to remove all the debris from the engine without a strip down, and this in itself can cause a serious blockage.

[Tiger]

Thanks Chaps.
Much obliged.
Tim

[Greig Smith]

The problem with many of our cars is that over the years they have been topped up from rivers, farm dams and farm wells with the resultant crud and scale that comes with such water. This is the stuff that tends to accumulate over the years and blocks the tubes to the radiator. When the motor is hot it circulates to some extent, (mainly floating around blocking the radiator tubes), but settles quickly when the motor is shut off and often doesn't move even when draining or flushing the block or radiator.

A very simplest way to remove crud etc from the cooling system on a 7 without stripping the engine down, is to insert a short length of stocking into the upper radiator hose. Remove the hose from the head, insert about 6" of stocking into the house using the handle of a screwdriver to gently feed the toe of the stocking up into the hose. Leave about 1" out the bottom of the hose which is is then wrapped up and around the end of the hose which is refitted onto the water off take. The lower hose clamp is then re-fitted over the upturned 1" of stocking. Go drive the car, but take a gallon of water with you and watch the gauge or the moto-meter or the rad cap or just use common sense.

Once it gets hot then shut down (withing coasting distance of a pub is always good), allow to cool somewhat and drain the radiator then pull the top hose off the head and gently pull the stocking out. It's usually full of crud and scale, you can just empty it & re-fit it & then fill the rad from your spare gallon. It takes a few sessions to clear most of the circulating crud.

This isn't a substitute for having the header tanks taken off the rad and the core rodded out, but it works incredibly well to catch the stuff that comes loose when things get hot.

Don't be tempted to stick the stocking into the top of the upper rad hose, the thermosyphon action pushes it into the header tank and snags into the sharp edges of the fins.... guess how I know...

This little trick works on virtually any car. All our classics have had it done at one or another time with great success.

Aye
Greig

[Nigel Ricardo]

I also put Screwfix central heating inhibitor in the radiator as it cleans the system.

[Bob Culver]

I tested my radiator at very low pressure in a water bath.It had been boiled vigorously with a restricted overflow and overpressured at soem stage. Although minor leak on car it foamed like an Alcaselser tablet! A bath can be made by laying plastic sheet in a rough wooden frame.