18 replies to this topic

[rae07]

I just swap in a refurbished engine. I reused the radiator hose (1.5yrs Kevlar) and the water pump (1 yr). Radiator is new. (Aluminium 2 core)

Everything is running fine. No overheating. However, I discovered a pool of coolant after having car parked for a while. Coolant is leaking at rate of 2-3 drops a minute.

I traced to the water pump area but it is dry. Found the joint from radiator hose to engine block wet but I could not assess if that is the source of the persistent leak or just wetting.

I tried pressurise the car by running the engine. However, there was no leak. Everything seems fine.

Other than the hose, are there other possibilities?

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[Quinlan minor]

It may be leaking from the water pump shaft seal. I've seen it where they will leak only when cold.

Try running the engine up to temperature and check then.

Alternatively, try getting some kitchen towel up in behind the bottom of the pump pulley to establish if that is the source.

Edited by Quinlan minor, 23 April 2022 - 07:19 PM.

[sonscar]

I have sometimes found that when reusing a hose that if the jubilee clip is not in the exact same position the hose is slightly distorted and can leak.When hot it is more pliable and seals,just a thought.Steve..

[rae07]

Thank you for your replies.

Quinian minor> The shaft seal you mentioned is the black area in the pic? And where would the water leak from? Can I replace the seal on its own or I would need to replace the water pump?

Sonscar> will probably try tighten the hose first and see if it helps.

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[Quinlan minor]

Quinian minor> The shaft seal you mentioned is the black area in the pic? And where would the water leak from? Can I replace the seal on its own or I would need to replace the water pump?

From where indicated by the blue arrow.

Not worth trying to replace a seal.

A new water pump is not expensive or difficult to source.

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[Miki Leyland]

Had a very similar problem last year. 

 

Engine and waterpump had only about 2 years then since being rebuilt (and very few miles indeed). I could never see the exact point where it was leaking, only some drops falling on the belt etc. After some months, the leaking became bigger and bigger until the engine was hot. Replaced the pump with good gasket and Hylomar sealant and problem solved so far.

Edited by Miki Leyland, 24 April 2022 - 09:17 AM.

[MatthewsDad]

I'd tighten everything up first before stripping anything out. I've just sorted two leaks following an engine rebuild. I thought the water pump was leaking but as sonscar suggests, it was just the position of the hose clip in relation to the re-used hose. Another leak was coming from a thermostat housing which was sorted by nipping the bolts a little.

[Spider]

One thing I don't like about Kevlar Hoses is they are quite firm and don't compress / take up as well as the 'rubber' types. In terms of fit they are no where near as forgiving to imperfections of the hose stubs. I don't use them for that reason and this maybe the source of your leak.

In regards to the water pump seal, and that was my first thought, there's a 'tell-tale' hole in the bottom of them, usually just outside of where the pulley covers the nose of the pump, if the seal leaks, usually that's where it will drip from. You might see it with a dentist type mirror.

[rae07]

To update, the pooling had stopped the next day. I checked the reservoir and radiator water level seems to have minimum loss.

This would mean that the water was pooling somewhere. Would a crack in the block or internal water jacket result in such symptoms?

Edited by rae07, 26 April 2022 - 12:23 PM.

[nicklouse]

This would mean that the water was pooling somewhere. Would a crack in the block or internal water jacket result in such symptoms?

Nope.

 

either you spilled some when filling. You have a leak somewhere so small you can’t see it when it is running.

 

or it might not be coolant.

[rae07]

Quite sure it is coolant from the blue tint.

It was leaking quite a lot previously and surprised that it could stop without significant coolant depletion.

Below is a video of the leak.
https://youtu.be/XeQEJ9895zs

Edited by rae07, 27 April 2022 - 05:16 AM.

[Spider]

As the system is essentially closed, it needs air to be let in to let it leak or some pressure in the system.

Pressurise the system and have a look to see if you can identify where it's leaking from. There are commercial tools for this, but if you have a hand or foot tyre pump these often have a chuck on them that has a rubber in them and a lever to lock them on the tyre valve. These will also fit on to the overflow on the Radiator, you may need a different Radiator Cap to get a seal where you need it, but you can use this arrangement to pressurise the system. Ideally use a pump that has a gauge, take it up to 15 PSI.

[nicklouse]

Quite sure it is coolant from the blue tint.

It was leaking quite a lot previously and surprised that it could stop without significant coolant depletion.

Below is a video of the leak.
https://file.io/xBwfKp1rQCIa

No file there. Load it onto YouTube.

[ac427]

One thing I don't like about Kevlar Hoses is they are quite firm and don't compress / take up as well as the 'rubber' types. In terms of fit they are no where near as forgiving to imperfections of the hose stubs. I don't use them for that reason and this maybe the source of your leak.

In regards to the water pump seal, and that was my first thought, there's a 'tell-tale' hole in the bottom of them, usually just outside of where the pulley covers the nose of the pump, if the seal leaks, usually that's where it will drip from. You might see it with a dentist type mirror.

 

Does this apply to silicone hoses also?

[Spider]

 

One thing I don't like about Kevlar Hoses is they are quite firm and don't compress / take up as well as the 'rubber' types. In terms of fit they are no where near as forgiving to imperfections of the hose stubs. I don't use them for that reason and this maybe the source of your leak.

 

Does this apply to silicone hoses also?

 

 

I haven't had my hands on lots of them, but those I have, I found them quite pliable and soft, softer than rubber in fact, so I'd say, they'd be quite good on distorted or damaged stubs. One thing though I'll add is if the hoses are fitted to anything that will have them under pressure, you'd probably want to be sure the stubs have a beading as they have a tendency to come away much easier than rubber and tightening the clamps can only make this worse as the hose wants to ooze out from under the tight clamp.