Fuel cooler leak

I changed the O rings on my fuel cooler on Friday.
It took about 2 hours with some cleaning here and there.
I found it a good opportunity to clean the heat exchanger tubes on the cooler, there was a small amount of sediment around the tubes and the lower tubes possibly were not flowing.
Those retainer clips are easy to take off, but as noted they are a swine to get back on. I shamfered one end of a 1/4" square nut and used long nose plyers to get them back on.
I also unbolted (4) the whole unit but did not take off the fuel lines, it is an easy enough job.

This link is very handy;

www.discovery2.co.uk - Leaking Fuel Cooler Fix

I did my fuel cooler O rings a long time ago. Turned out it had started leaking because the head gasket was gone and started to pressurise the cooling system. I then spent another couple of months chasing various leaks until I got the car tested on the Dyno.

If you start chasing leaks like this, start the car, take it for a quick flogging and then stop and crack (don't open it too fast) the overflow bottle lid on the cooling system. This is best done with the engine not to hot as you don't want it to burn you.

If the head gasket is gone the tank will be pressurised.

I hope this is not the case for any of you out there but it is always worth checking.

The cooling system is always pressurised a certain amount, thats how it works otherwise the water would simply boil away at 100°

If you have any original hose clamps from your Disco spare(maybe from changing to silicon hoses). Then the original Land Rover hose clamps are thin enough to use instead of stuffing around with refitting the original fiddly clamps. This also enables the O rings to be changed in the future without having to remove the fuel cooler.
I found that the aftermarket hose clamps available are all too wide for the job.

Cheers,

Jason

for anyone wanting to bypass the cooler, a standard holden commodore (i think) fuel filter will fit straight onto the quick connects and thus would require no changing of the fuel line fittings and only blocking off of the water lines.

Quote:

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Originally Posted by mydot378

The same! found mine leaks when cold,but takes up when hot, I was actually going to do away with it, replumb the water lines and just leave the fuel lines as they are (atm). Has anyone else give this ago? I really cant see what benefit the cooler has anyway?I remember reading a test on fuel temp in some book, the outcome was it made no difference with or without a cooler( hp wise that is).Any ideas guys???? Ross

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Hi Ross.
DEFINATELY NOT A GOOD IDEA.
The fuel cooler cools heated diesel leaving the head before it returns to the tank.
Without it the fuel in the tank has the potential to get dangerously hot on a long trip.
If you were to replace it you would still need to consider some other method of cooling the return to tank diesel,auto trans cooler perhaps???
Andrew

Don't remove the cooler.

As Andy said it is important

Quote:

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Originally Posted by LandyAndy

Hi Ross.
DEFINATELY NOT A GOOD IDEA.
The fuel cooler cools heated diesel leaving the head before it returns to the tank.
Without it the fuel in the tank has the potential to get dangerously hot on a long trip.
If you were to replace it you would still need to consider some other method of cooling the return to tank diesel,auto trans cooler perhaps???
Andrew

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Yeh Andy, after some disscussion at work,your totaly correct,I forgot about the fuel running through head (still think i have the old 300tdi)!!!so yes as you said I am going to do away with the original cooler and go a auto trans type (or similar) ,so no more water leaks and the new cooler being air cooled is more efficient anyway,,, Happy Days Ross

Quote:

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Originally Posted by mydot378

Yeh Andy, after some disscussion at work,your totaly correct,I forgot about the fuel running through head (still think i have the old 300tdi)!!!so yes as you said I am going to do away with the original cooler and go a auto trans type (or similar) ,so no more water leaks and the new cooler being air cooled is more efficient anyway,,, Happy Days Ross

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Don't forget the :rulez:

:D

Kev..

Quote:

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Originally Posted by Jason789

If you have any original hose clamps from your Disco spare(maybe from changing to silicon hoses). Then the original Land Rover hose clamps are thin enough to use instead of stuffing around with refitting the original fiddly clamps. This also enables the O rings to be changed in the future without having to remove the fuel cooler.
I found that the aftermarket hose clamps available are all too wide for the job.

Cheers,

Jason

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Some smaller aftermarket clamps are narrower than the large ones - just use two small ones on each end.