Changing the DHC’s water pump

With the Alpine Tour only a few days away there was no time hanging around, which meant an early start this morning. First I had to collect all my tools which were scattered over a few different locations. But before I started on that round I soaked all the nuts and bolts, that needed undoing on the engine, with penetrating oil.

After having collected all the tools I started with draining the coolant system and disconnecting the carburettors, in preparation of the removal of the complete manifold/carburettor assembly;

As I had already filled up the fuel tank in preparation for the scheduled trip to the Alps, I had to make sure the fuel hose coming from the pump was closed of properly. So I clamped the hose using a small ViceGrip and plugged the end;

With everything disconnected it was time to remove the manifolds mounting bolts. All could be removed without a problem. Only wondering what Muppet at Leyland designed the manifold, as the front bolt is pretty much inaccessible for a half decent socket set. Luckily I do have various spanners, but due to the limited space it was rather time consuming to remove this bolt;

But with all bolts removed and the heater pipe disconnected (nearly forgot that one) the manifold together with the carburettors could be lifted of the engine;

Giving me chance to look inside the engine for the first time in 17 years, doesn’t look to bad I think;

And after a minor break to make a brew, I tackled the water pump itself. Removing the cover was very easy, two taps with a rubber mallet and it was out. Was amazed to see that the gasket was blown out at the back of the cover. But there were no signs of any leaks from there;

The pump itself did put up something resembling a fight, but it lost out against a sturdy washer, screwed to the pump’s shaft, and two hefty tyre levers. The impeller gave the game away why the pump failed. There is a fair amount of rust on it, almost certainly caused by being in contact with air for nearly 18 months;

Of course the brass cage remained behind in the block;

... but with this little tool it was a piece of cake;

After removing the old gasket and cleaning the inside of the pump cover, it was time to refit the pump. It did take a few attempts to get the jack shaft gears to engage with the gears on the pump shaft. But ones I got that right, the pump could be gently tapped in place;

Left me with checking the clearance of the pump cover;

Choose a gasket with the correct thickness (measured gap + (0.30÷0.50) mm) for the 12 vane impeller;

And tighten the water pump cover;

Only have to refit the manifold etc. but I ran out of gaskets and O-rings. Will get that sorted tomorrow morning, so hopefully the car will be ready by evening.