Thread: TD5 Fuel Cooler leaks.

haha, this forum is magic!
Went offroad this weekend at Springs and it's quite cold up there, and got the same leak....
Once the engine warms up and coolant warms up, the leak stops - so i thought no ways am i spending huge $$ on a new cooler if it's only a gasket!!
And now this morning i notice this thread with o-ring numbers and all.....
Way to go, trip to shop for parts and then hopefully a quick-ish fix
At least i am not the only one with a leak

For everyone with a fuel cooler leak, my experience was that as I fixed each leak a new one appeared. The root cause was the head gasket pressurising the system and then showing up all the places that were the next weakest link.

As a general rule, if after starting the car with the coolant cap fitted pressure builds up quickly (ie crack the cap when the engine is just warm and a lot of air comes out) then you have bigger problems.

Hope I am wrong. Good luck.

I hear what you say, but mine (and i assume a few others as well) leaks when car is standing and engine off. Coolant will drip slowly and when cap is removed from reservoir will drip considerably faster. Once motor was running and everything heated up, leakage stopped, as if the heat makes the o-ring expand and seal. So for now i'm not worried about the head gasket - but will obviously keep an eye on things as TD5's and heads means big $$$$

Exactly the same problem.....front of fuel cooler and only leaks when engine has cooled down. This seems to be a fairly easy fix, so 1 down and 2 more to go - water pump and broken bleed screw.

Exactly the same problem.....front of fuel cooler and only leaks when engine has cooled down. This seems to be a fairly easy fix, so 1 down and 2 more to go - water pump and broken bleed screw.

Thanks guys.

Just found this thread, save me some money.

Baz.

Originally Posted by Tombie

The O'ring is EXACTLY the right size, and is as specified in the LR manual. It is also the correctly sized part based on its housing dimensions....

The old one is Wider due to taking a set from time/heat.



[B][COLOR=Green]Do NOT put silicone in the groove, nor in front of the O'ring.
An understanding of how an O'ring actually seals will let you know you have just rendered its function useless, and you're now sealed with a lump of silicone, not by the o'ring itself.

Better to use a rubber grease and smear it **lightly** on the o'ring and housing before re-installing.

When drifting it back in, do it SLOWLY to prevent the o'ring rolling over itself and pinching.



[B][COLOR=Green]Other than that, excellent write-up!

Hi I am back.
It seems after nearly four years many people have read my little piece about how to repair the leak in a TD5 fuel cooler.
I had some very good complements and some criticism as well.
I note there are other contributors to this problem who on other web sites are using my original technique of knocking the front clip of the fuel cooler as I suggested and pulling the front plug of the cooler out of the stainless steel housing by pulling hard on the front coolant hose. Some use my suggested silicone and some use many different suppliers of after market O rings.

Pulling the fuel coolers front plastic plug out in situ seems to be a standard quick fix now which allows you to leave the fuel cooler on the car and I have also done it a few times since to other TD5s as well.
There has been some criticism about using silicone on the old O ring and this being a bad technique. I agree its not perfect but I can assure you the silicone does work.

I have done over 100000Km in the TD5 since I did the original repair and it was fine.

I was recently in that area of the cars engine and had to cut the plastic tie I placed on the front fuel coolant water hose. To see what would happen, I decided to not replace the tie. Sure enough the front of the fuel cooler started to leak again after 5000kms. So I would suggest please tie the fuel cools front coolant hose to something on the engine so it does not vibrate as much.

The bottom line is the silicone does work and you will get over 100000kms.
I accept the criticism from "Tombie" that putting silicone under and over a O ring is not standard but my reasoning for doing that and perhase I should have explained was I did not want the O ring to move at all so the Silicon above the ring could hold for as long as possible. So I was just using the old O ring as packing and the O ring was not being used at all for sealing.

I now think if your lazy then putting Silicone all over the top of the O ring and even into the spare groove next to it is also probably just as good and it is how I have recently done it on friends cars. I thing the more silicone contacting surface area the better. The job should last longer. Considering I only used the bare minimum silicone around the original O ring the first time I did the job and the result was I got over 100000Kms tell you it works and a bit more silicone would be better.

So as I suggested before in my original post all those years ago use the new O rings if you like and there does seem to be a few different kits on ebay now which there was not when I originally did the repair years ago. Also I like the thin screw clamp that one supplier is offering and would make for a secure fir of the plug. Remember the clamp only holds the plastic plug in place. It does not clamp onto the O ring at all. But stopping the plastic plug from vibrating is important in longevity of this job.

Back to the criticism I have received regarding my comments about the suggested O ring being used by many. When I contacted the dealer all those years ago the first time I did this there was no repair kit for those O rings or part number either and I note even now there is no genuine O rings being offered either. Only after market vitton etc. The part number being suggested is from after market manual as well. I do not believe there is a genuine part for this repair. I would like some comment here from the experts among you. What we are offered and told here in Australia is **** compared to what you have in England etc.

So if you have to do this job then the silicone will work for a number of years and big deal if you have to do it again. Having done it a few times now it’s a 20 minute job and the waiting for the coolant to run out is the biggest drag but I just go and have lunch and come back with the compressed air to dry it all out. Clean the surfaces and a bit of silicone and its done.

I really think the silicone is better than the O rings because the silicone will hang onto the sides to compensate for all those differential contraction rates of the plastic and the steel when it is very cold. The O ring just gives up after it’s a bit cold and shrinks away from the stainless steel case. Hence the pool of coolant after a cold morning. Also tie the front coolant hose off to something on the engine not the body of the car. I tie the fuel cooler coolant hose to the front radiator hose. Stops all that massive wobbling.

I have got a feeling the next time a write about this it will be in a classic cars book on old rovers.

Take care everyone.
　

Originally Posted by x-box

I hear what you say, but mine (and i assume a few others as well) leaks when car is standing and engine off. Coolant will drip slowly and when cap is removed from reservoir will drip considerably faster. Once motor was running and everything heated up, leakage stopped, as if the heat makes the o-ring expand and seal. So for now i'm not worried about the head gasket - but will obviously keep an eye on things as TD5's and heads means big $$$$

Just to add to this.
When the TD5 Fuel cooler leaks coolant from the front because the O ring is worn.
This only occurs when the engine is cold and nearly always in the early morning. I have not seen much if any leakage while the engine is warmed up. If there is leakage when the engine is warm then you probably may have a cylinder head gasket leak. Check for hydrocarbons in the coolant if this is the case using a coolant hydrocarbons checker or die etc. Local mechanic will have some and may help you.

If this is the case then there is a lot of pressure in the hoses when you squeeze the top one. Engine off before you try this and it will be very hot.
The excessive pressure will eventually burst a hose or seal like the front O ring in the TD5 fuel cooler which may be on the way out. This is nearly the only time the fuel cooler will leak when its hot.

So I agree the O ring does expand when hot but it may be so worn and flat that it still leaks when hot because the coolant pressure is too high.
The secessive pressure usually coming from the cylinder pressure leaking into the coolant chamber. Usually this is head gasket related.

A little tip is if there is excessive pressure in the coolant then to prevent a blow out of the coolant because of the excessive pressure, then just wind the coolant cap off a few turns so the pressure can escape so at least you get home or to the garage without blowing a hose.

Some mechanics will squirm at doing this but at least you wont loose all your coolant if a lower hose bursts which if not noticed will damage your engine. Keep checking the level of coolant to make sure it’s not steaming off or being pushed out any leaks.