Fill Coolant Tank and immediately drips near the water pump
 

Trying to get to the bottom of this issue. Last month i installed the oil cooler seals and can see no mixing of the water and oil. I did however start a leak and having a challenge finding the source. I will put 3 litres of water into the tank and it will be on my floor within a few days. When i refill, it will start to leak within seconds of the refill. Drips steadily from the water pump area near the oil cooler seal. Thinking it's a clamp or hose but stuck on removing the air box, air flow meter, j-boot etc because the of the phillips screw that is hidden near the coolant tank is seized.

Any experience on how to remove this? Very hard to get at without an extended phillips screwdriver and afraid to mash the head on the top of this bolt/screw...

I've removed the power steering, a/c tensioner belt and tensioner etc then removed the cover for the timing belt and cannot see anything. need to get a little deeper and stuck on the bloody air filter housing bolt/screw

any other thoughts on the source of the leak?

Get one of those little hand pumps you can attach at the radiator cap to put some pressure on it and accelerate the leak. That may help your investigation. I believe there are dyes you can add to the coolant that show up under a black lite but not sure if that will help you all that much. I think the most common failure mode that shows up suddenly would be leakage at the water pump shaft seal. That long metal tube that goes from the front to the rear next to the exhaust can be corroded and start a leak.

I did a blog post on my website recently about how the coolant system is organized that you might want to refer to.

thank you sir.. I'll check them out.. Can this seal be replaced/repaired without taking everything out ie: timing belt and water pump?

You might try spritzing the rusty bolt with PB blaster and waiting overnight. if still stuck, you might be able to get a small microflame (butane) torch in and heat the bolt up a bit, then cool down with more PB..Have a wet rag handy in case it flames up a bit..then cool it down with more PB. Works about 75-80% of the time for me on ancient bolts.
Hope this helps some.

I had a leak from the gasket between the WP and the block that appeared about a year after I replaced the pump. In those areas, it's very difficult to determine the source of a leak. For me it was fairly obvious since I opted to leave the belt covers off. Is it possible to cut that hose clamp off w/a dremel?

@tiger good tip, soaked with penetrating fluid a few days now - will hit it again this weekend, hope i don't need the flame but good tip... this bolt not that old... air filter changed about a year ago

@ben i sure can cut the hose clamp but really need to get the air box out of the way to get to the rest of it. covers are offer so will be better able to see the source of leak

will have time this weekend to wrench and will report...

If the shaft seal on the water pump is leaking, you will need a new pump. I don't know what the life of a water pump is but many people change them out at the same time they change the timing belt.

Obviously, once you get in there tighten all of your various hose clamps, as these can loosen over time. That would be your best case scenario :) Another thing that happened to me once was a radiator hose got into the cooling fan blade. That caused a massive leak. But if it leaks purely under the gravity pressure of filling up the overflow tank, my bet would be on the shaft seal.

I think I will look for a new pump and replace. not sure about the timing belt so will remove and inspect. how do you know when to replace? look for crack in the belt or just replace every so often. do you use the old style pump or new style water pump which according to clark's garage needs a different size idler roller 46.2mm vs 32mm.

best place to buy? rebuild or new? has anyone ever bought a rebuild kit? any special tools needed ie: press etc?

I did get the air filter housing off. I removed the two 10mm bolts in front and two in the rear. was a bit of a wrestling match and I did bend the housing metal frame and... still cannot get the bolt off. I'll use some more encouragement when I get back to it this weekend! it's been a bit chilly to work in the garage in Toronto.

with the air filter housing off, I could follow the coolant tank to the rad, then it goes into the motor and directly behind the timing belt cover is the leak. I have the timing belt cover off and could take off another cover if I removed the distributor. I think it could be cracked block (water was left in the rad) or water pump seal failure. looking on clarks garage, looks like a pretty straight forward job to remove the water pump.

For what it's worth, I just did the timing belt on my 931, made the conscious decision NOT to replace the water pump, and immediately had this exact same problem once I buttoned it all back up. I was sure this was karma biting me for not replacing that pump. However, I ran the car up to temp and figured out that the leak was actually a pinhole leak near a clamp on one of the coolant hoses....at pressure, it was coming out in a tiny stream. However with no pressure, it was dribbling out, running down various edges, until it eventually dripped off the bottom of the water pump.