Hole underneath water pump

[lockupchap]

Not been on here for a while, as spare time tends to arise in occasional 'dollops'.

My 1970 Traveller restoration's now nearly complete, and in the last couple of days I've tackled a few of the remaining finishing touches such as glovebox fitting and adjusting the brakes.

Many months ago I fitted a recon engine, but ran it to full temperature for the first time only a few weeks ago, during the last time 'dollop'. All seemed good. However I noticed today that the coolant's dropped a long way, and a pool of the stuff is on the garage floor. It appears to have been lost through a hole drilled in the bottom of the water pump. The pump is of unknown age or condition, but no coolant loss was visible when the engine was running nor soon afterwards.

Can anyone suggest why this has happened, and the purpose of the hole?

Years ago I had the same problem on a low mileage Metro 1.3, and changed the pump but never really understood why the coolant had suddenly been lost through the same sort of hole, after no problems until then. I've also noticed coolant stains and drips under the hole on other A series engines, but don't understand why this happens, why it can suddenly get worse or why the hole is there.

[les]

I've been slightly mystified by that hole myself at times. There was a grease nipple fitted to pumps years ago, whether the hole is a left over or not I can't say. If the leakage is from the hole, it may be a sign that the internal gland seal has gone.

[philthehill]

The hole in the underside of the water pump is and was to let any water that gets past the gland/seal out and not get into the bearings.
When coolant appears from the hole it is a good indicator that the pump needs replacing.
If you do not turn your engine over on a regular basis the gland/seal can stick and when the pump/engine is finally turned it starts to let water past.
Attached is a cut away drawing of the water pump, earlier model I know but the principle is the same on the modern pumps.[frame][/frame]

[les]

From that picture the grease nipple has been replaced with a screw, and completely separate from the hole in question.

[bmcecosse]

You could try fitting a grease nipple - and pumping in some grease in the hope of re-seating the seal. But really a new pump is not expensive and will save any worries about losing water.

[LUR759H]

yes grease it will also reduce noise while engine is running and it works to stop the drips!

hope this helps

Alan
69trav

[alexmcguffie]

Its exactly as philthehil says. I'm assuming you've not turned it over between dollops of time, the seal has stuck to the shaft and then 'torn' when turned. I've seen the problem with Lotus Twin Cams but thats a much more expensive job to fix! New pump is the way to go, grease won't fix it.

[philthehill]

If you do fit a new pump check the clearance between the impellor and the pump body. The clearance is not always as it should be and recently have had to press the impellor further onto the shaft to get the right clearance. See illustration below for correct clearance:-[frame][/frame]

[Barry Brown]

It is a drain hole. When it leaks it lets you know the seals are compromised either through splitting, bearing failure or rusted shaft. It is time to change the pump. Makes sure you buy the type with cast impellor as the pressed steel ones are c..p!
It is rare these days to find the old style pump that you could recon - more chance of stepping in rocking horse doings.

[lockupchap]

Thanks guys - a new pump it is then.

The failed one was actually taken off an old 948cc engine that came as part of the job lot when I bought my pop-riveted traveller with a stock of assorted spares. It had stood for at least 22 years, so no surprise that internal felt and/or rubber had failed through age.

[bmcecosse]

Note there are Large and Small impeller pumps. The Large is intended for 1275 engines, but 'may' fit some 1098 engines. The Small is intended for 948 and 1098 engines.