Mercedes 814DA coolant leak?

[NigelEvans]

Got a problem I’m hoping someone may be able to help with. I’m losing around 2 or 3 litres of coolant per day (of driving). The truck’s never overheated and I’ve been unable to locate an obvious leak. On a couple of occasions I’ve spotted a tiny pool of water under the truck in a position that corresponds with the reservoir overflow. This issue seemed to start around the time I had the calorifier heating coil fitted. This is fed by long flow/return rubber hoses that run from the front to the rear of the vehicle. Initially I suspected a defective radiator cap, on inspection this appears to be fine. I’m now wondering about the coil feed hoses expanding under pressure, drawing water from the reservoir, then shooting it out through the overflow pipe when it cools. Does anyone else have a similar set-up or problem or any idea what may be going on?

 

[canals1164]

Just a thought but as a fully fledged farmer I would try two ideas:
1 can you tie a can to catch the water from the overflow, it would confirm that it is being pushed out of over flow.
2 Perhaps try putting 1litre in and seeing if you only need to add 2-3l the next day, if so you would know you are right on the expansion idea.

I guess you are probably right in that the calorifier will have quiet a marked increase in expansion within the system.

good luck

 

[ianc]

What sort of piping did you use to the calorifier? I used flexible braded piping from the engine connection back to just behind the cab seats. The remainder is "Qualplex" with pretty well no expansion. I've not seen any loss of coolant. But then - I've been driving in chilly Ireland and even then - not much mileage.

 

[NigelEvans]

Going to give the can under the overflow a try on my next run as suggested.

No markings on my piping - Looks like black rubber radiator hose.

If excessive expansion is the problem not sure what I can do about it apart from replacing the pipes or increasing the size of the tank. Either job would be a complete *****!

Thanks for the advice.

 

[ianc]

Does the piping look or feel like it's expanding? If it's not - then I'd be surprised if that was what is causing the problem. If it is visibly expanding then you would have to ask if it's up to the job longer term or might it let go.

 

[NigelEvans]

Found it! Not excessive expansion just a stupid leaking union.

 

[canals1164]

phew frustrating but not expensive!!