Water leak - maybe the water pump seal?

[minimeadow]

I drained and filled the radiator on Saturday. The car has been sitting dormant for years, and only about a quart came out. I refilled it with tap water, thinking that I will drain and refill with a distilled water/antifreeze mix once it's running. Today I noticed a small puddle under the car. Looking closely, water is running down from the front of the engine and dripping off the engine sump at about 2 drops per minute.

Is the water pump seal the most likely source? Difficult to fix? From a quick scan of the service manual, it seems I need to take the radiator out and then remove the fan, which will give me access to the pump.

Also, any advice on what parts to buy? Looking at Moss Motors, the water pump rebuild kit is not available, but a new reproduction water pump is $139, and maybe I should just go that route.

Thanks all for your thoughts on this. Best, Scott

[Glyn Ruck]

Buy the new & improved water pump. It's likely the shaft seal. The impeller design has been improved to move more coolant. Don't exceed a 9lb radiator cap. I've settled on 7lb. The 4lb cap is a joke & seldom seals at all. Obviously check all hoses.

[cass3958]

Generally it is not the water pump gasket but the water pump itself. There is a small breather hole just above the bearing/seal which is where the water seeps out of. (Indicated in the photo by the yellow arrow.)

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This can be caused by the seal on the impellor leaking allowing water to go to the seal and out of this hole. If this has gone then you are looking at a new water pump as the seal and bearing are very difficult to change and the chances are that the water pump bearing will have gone anyway. You might even find the impellor is corroded as it is made from Alloy.
Also check that if the bearing has gone that the impellor has not come into contact with the housing and caused a deep enough score mark to allow water to run into the chain area. You can see the scoring on my engine in the photo below which was due to the bearing being worn and the impellor not running true. This was not bad enough to cause concern and a new water pump allowed better clearance and a straight impellor blade.

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Replacing the water pump is not that hard once you have the radiator out of the way and if you remove the front grill at the same time as this allows direct access to the front of the engine. My only words of caution are to protect the back of the radiator from the front of the fan with a sheet of cardboard as it is very easy to put a blade of the fan through the back of the radiator. When removing the front grill the nuts and bolts are very small threads to be careful to soak them with a good lubricating solution before trying to undo them and lastly the radiator shroud has to be left hanging over the fan when removing the radiator as there is no room to remove it between the radiator and fan blades but that also means you have to remember to hang the shroud over the fan before lowering the radiator with cardboard protection back into the car.

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When replacing the fluids I personally like to flush the coolant system with a high power stream of water from a hose. Disconnect the top and bottom hoses from the radiator and then push a water hose as far into the engine as possible and run the hose for several minutes. You will be surprised how much muck comes out and for how long the water runs rusty red before turning clear. Do the same with the radiator and the heater matrix.

[minimeadow]

Glyn, Cass, thanks once again - looks like a new water pump is in my future. Best, Scott

[John Quilter]

And if removing the radiator you might consider changing the rubber donuts that it sits on at the bottom and the ones at the side mounting ears as these tend to age and perish.