Well... I finally got to the bottom of the nasty water leak coming from the water pump... #dontlikegaragistes

It turns out that Le Garage that fitted me a new water pump (to solve a leak at the spindle that started whilst Gerrard was on Le Peripherique in Paris... 34C and stuck in the traffic jams did for it...) managed to nick the edge of the rubber o-ring on the machined face of the engine block.

Ever since then it's been leaking .. and obviously it gets worse when the system is hot/under pressure... so I had to dismantle it for a look, since I can't afford another holiday in France and therefore the prospects of taking it back to be fixed/done properly are zero.

It's not all doom and gloom, since I fitted a new tensioner and a cam-belt whilst it was apart.. and then a new aux belt tensioner to finally cure the annoying squealing it made just off idle... but since the water pump turned out to be a nicked o-ring, rather than just a loose bolt etc. as I'd hoped, I could only re-fit the pump with a load of sealing gaskety goo around it and hope for the best.

But the goo hasn't worked and the pump is leaking again.

This time I have a new O-ring (it came with a new pump attached, c/o fleabay) but I dunno if I have the energy to swap it out again right now.

Plan B is just to stick Radweld in the system and see if that cures the dripping... but I dunno if that will work. The radaitore is new too, so I'm partly reluctant to stick something in there that may start to clog it up in some way.

The o-ring itself had a fair piece missing from the outer edge and the gaskety goo I used (Blue Hylomar) obviously hasn't sealed it. Does Radweld block such gaps or does it not stick to rubber etc.?

I dunno why the Hylomar didn't fix the leak.. normally it can hold back anything. Is Hylomar glycol resistant? Would silicone gasket have been a better bet?

Plan A is to fit the new pump (Fiat OE) with its new gasket.. but if I can do it later c/o a temporary fix, I may be tempted..


Ralf S.

Ralf S. said:

the water pump turned out to be a nicked o-ring, rather than just a loose bolt

Plan B is just to stick Radweld in the system and see if that cures the dripping... but I dunno if that will work. The radaitore is new too, so I'm partly reluctant to stick something in there that may start to clog it up in some way.

Click to expand...

I would only ever use Radweld type products in an emergency and only for a short period. They can clog up the small bore cores of modern radiators.

Although the O ring is damaged, the leak could also be coming from the left water pump bolt. The bolt hole is not blind, but goes through into the cylinder head water jacket. If the garage in France didn't fit a new bolt, or reseal the old one, water could be leaking from there.
.

Hmm.... good tip. I'll have a look.

If the pump looks water tight but the leak is coming from the bolt, it will save me dismantling everything again. I'd just need to remove the top (and maybe the bottom too) cam-belt covers but leave everything else alone.

Ralf S.

I dismantled everything again, since the water pump bolts are tucked away behind the cam-belt runs, so I couldn't see them, let alone access them.

It turns out that the bolt was not re-sealed, so it was dripping ... and the "patched-up with gasket sealant" O-ring still wasn't having it.

I fitted a new O-ring with plenty of gasket goo next to it (although strictly/ordinarily I wouldn't use any .. ) and sealed up the bolt.

Apart from something that I stopped from squeaking last time (new aux-belt and tensioner silenced it for a while) that has started squeaking again, the beast has remained water-tight..

Next job will be to suck out some cooling water from the header tank and replace it with neat anti-freeze, since the beast was getting topped up so often that the pink stuff has been diluted right out.


Ralf S.

Ralf S. said:

I dismantled everything again, since the water pump bolts are tucked away behind the cam-belt runs, so I couldn't see them, let alone access them.

It turns out that the bolt was not re-sealed, so it was dripping ... and the "patched-up with gasket sealant" O-ring still wasn't having it.

I fitted a new O-ring with plenty of gasket goo next to it (although strictly/ordinarily I wouldn't use any .. ) and sealed up the bolt.

Apart from something that I stopped from squeaking last time (new aux-belt and tensioner silenced it for a while) that has started squeaking again, the beast has remained water-tight..

Next job will be to suck out some cooling water from the header tank and replace it with neat anti-freeze, since the beast was getting topped up so often that the pink stuff has been diluted right out.


Ralf S.

Click to expand...

Just release the drain plug and fill the beast back up again.

Or - remove the small top hose off the tank, block the hole and connect this to another tank to catch the return - not sure how well and safe that would be as the system will be under pressure once the thermostat opens and starts allow the fluid to run around the head etc.

I have a little hand pump that I bought to drain a fuel tank once. It'll only need a few seconds to empty out the header.

I'm guessing the cooling system holds about 5 litres (I'll have to look it up in my handbook) so if I can get 2.5 litres out, I can put in the same amount of concentrated coolant to give me an approx. 50:50 mix.


Ralf S.