Mysterious Water Leak

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David
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Mysterious Water Leak

Post by David » Mon Nov 10, 2014 10:04 pm

Hi all. After putting my BX back together again, I have come across another potential problem... It appears to be losing water out of the radiator.

Admittedly this isn't the first time I've noticed it, I previously thought it might be air in the system, but after giving it a good run & getting it hot, water still seems to be disappearing in to thin air.

I have had a good look around it & can't see anywhere it could be going to. The head gasket was replaced when I put the 4x4 system on it (due to an external oil leak) & it doesn't appear to be getting water in the oil, I've changed the heater matrix & tap, (which are known good ones), I've checked the hoses & replaced some that were cracked, & I've even replaced the water pump but its still the same.

Anyone any ideas what it could be?
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

2004 Citroën Xsara Desire. (Now gone).

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themildbunch
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Re: Mysterious Water Leak

Post by themildbunch » Mon Nov 10, 2014 10:57 pm

I've had to replace many older hoses on both my diesel BX's.. The N/A's cooling system tends to need topping up over a while after refilling as it gradually purges the air... I've found the TD easier to bleed but they can both suffer from gradual coolant losses which are hard to see.. I have the red coolant in a high concentration and this makes it easier to spot a weeping hose.

On my N/A BX the small 3" long hose under the thermostat housing was leaking but only when gradually cooling down, dripping coolant onto the top of the gearbox..

I've also found the quality of hose clip can make a big difference. I always use genuine Jubilee clips and these seem to hold much better. Another good trick is to smear the hose connections with silicone before refitting the hoses. This really helps on older alloys housings where they can corrode and the mating surface becomes rough helping leaks!
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David
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Re: Mysterious Water Leak

Post by David » Mon Nov 10, 2014 11:49 pm

Thanks for the reply.

The 3" hoses are 2 of which that have been replaced because they were cracked (one at the side & one behind).

I will try the silicone trick on them (or the ones I can get at) & go from there then.

Any more suggestions would be greatly appreciated.
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

2004 Citroën Xsara Desire. (Now gone).

2011 Ford Focus Zetec - Daily Driver. (Absolute bone shaker).

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Re: Mysterious Water Leak

Post by Way2go » Tue Nov 11, 2014 12:11 am

Personally I have found Jubilee clips quite problematic as they are not absolutely circular. They are fine for the large OD hoses but not the smaller OD.

This really shows up most on pressurised systems as the hose stays in place but can squirt from the non-circularity points.
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Re: Mysterious Water Leak

Post by Tinkley » Tue Nov 11, 2014 6:28 am

David wrote:Hi all. After putting my BX back together again, I have come across another potential problem... It appears to be losing water out of the radiator.

Anyone any ideas what it could be?
Could be a small pinhole in the rad itself. I have had this with a known good radiator ie new Serck replacement and it always had ultra clean anti freeze/distilled 50/50 mix in it. The engine waterways were known to be clean and hoses in good condition.

Quite tricky to spot as when warm, the coolant evaporates on the finning, and does not always leave a tell tale stain!. Best way I found to find it was look very hard after a short run in dry weather, to see any water at all, in my case a minute trace on the engine side (back) of the rad itself. I suspect a small stone thrown up by other trafic did the damage. Even salt grit has stones with enough mass to pierce the matrix especially if you are overtaking a gritter.... :wink:

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Re: Mysterious Water Leak

Post by electrokid » Tue Nov 11, 2014 12:13 pm

Another good trick is to smear the hose connections with silicone before refitting the hoses.
Always use silicone rubber - but not too much so avoiding putting it into the waterways !

A thin smear on mating surfaces even if they are gasketed works well also except for head and exhaust.Silicone rubber is normally good up to 300 C. Use normal acetoxy cure stuff unless it's near electrics in which case use neutral cure. And if you're doing some plumbing using comression joints - a thin smear over the olive and arround the thread - again try to avoid getting it into the waterway itself.
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Re: Mysterious Water Leak

Post by rutter123 » Tue Nov 11, 2014 12:20 pm

Stand the car overnite after a good run, place some clean cardboard under the engine bay this may give some indication where your leak is, i have had pattern water pumps leak on the shaft after 20k, also always fit 2 gaskets on the pump to be doubly sure, old hoses can be suspect worth checking things like rad switch, coolant level switch etc and of course get yr rad pressure tested and look for signs of corrosion along the bottom of the rad. I had a similar prob years ago and a new rad cap cured the prob.
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Re: Mysterious Water Leak

Post by Defender110 » Tue Nov 11, 2014 12:24 pm

Tinkley wrote: Could be a small pinhole in the rad itself.

Quite tricky to spot as when warm, the coolant evaporates on the finning, and does not always leave a tell tale stain!.
Seconded; small leaks on rads can be very hard to spot as they sometimes only leak when under maximum pressure accelerating etc. then evaporate before you have lifted the bonnet. look out for steam on the rad.
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Re: Mysterious Water Leak

Post by David » Thu Nov 13, 2014 11:42 pm

Thanks for all the suggestions.

When I replaced the water pump I put silicone around both sides of the gasket, so that shouldn't be leaking.

I pulled the radiator out yesterday, had a look around it & it looks OK, So I washed it out, pulled all the accessible pipes off the front of the engine, put silicone around them & reassembled it. While the radiator was out I put some PTFE plumbers tape around the fan switch, some silicone around the low water level warning switch & some silicone around the rubber plug at the bottom of the radiator.

I then reassembled it all putting silicone around the radiator pipes.

I think 3 of the unions were leaking, the top radiator hose; both sides & The small pipe going from the thermostat to the oil cooler on the thermostat side.

I also replaced the cap with the one off Mulley's cars' radiator.

I have yet to fill it up & try it, but hopefully the silicone has sorted it.

Thanks again for the suggestions.
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

2004 Citroën Xsara Desire. (Now gone).

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Re: Mysterious Water Leak

Post by Mothman » Fri Nov 14, 2014 6:56 am

Did you pressure test the rad? Thats the only way to tell if its leaking.

Andy

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Re: Mysterious Water Leak

Post by Kitch » Fri Nov 14, 2014 1:23 pm

Have you got an oil cooler? They can leak internally giving HGF symptoms.

You really need to pressure test the cooling system though by the sounds of it.

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Re: Mysterious Water Leak

Post by David » Tue Nov 18, 2014 7:02 pm

Thanks for the replies.

I didn't have the radiator pressure tested because I believe I had located the problem & it didn't look damaged, Although if it still gives problems I will ether have it checked or get a new radiator.

The car does have a oil cooler. I don't think there is anything wrong with the cooler or head gasket, I just said it had been replaced because I have read that water can be lost through a leaking head gasket.

I can't tell yet if is still losing water or not. Time will tell.

Thanks again for the suggestions & help.
1992 Citroën BX 1.9 Diesel Meteor 4x4 - The Project.

1992 Citroën BX 1.9 TXD (with GTI engine; Mulleys old car) - Parts car.

2004 Citroën Xsara Desire. (Now gone).

2011 Ford Focus Zetec - Daily Driver. (Absolute bone shaker).