We have just had a new head gasket fitted after a major overheating episode. On our first trip out yesterday we noticed that after stopping for a while there was a small puddle under the car dripping down from somewhere above the axle at the nearside front wheel.

On arriving home there was a further brief trickle after the engine was turned off. This morning it was dry but on releasing the radiator cap the leak restarted. Also the expansion tank is quite full. (unfortunately until reading the site we had been filling by the rad cap and so don't know what its level was before we left.

Any help we be much appreciated as we can't see an obvious source of the leak and would like to avoid a repeat of the costly overheating.


- (#9100) Chris, 15 Jun 03 4:15

If it leaves a puddle you should be able to identify it if you keep looking
One tip - if the coolant hose is leaking where it seals over the spigot - a cable tie between the clip and spigot can stop the leak as a temporary but basically sound measure (make sure the tie does not have sharp edges)
Check your top and bottom hoses as a first measure after a run - when the coolants hot the pressure will push it out of holes - as it cools it has a vacuum effect - when you undid the cap the vacuum was broken - The fact it leaked when cold to me suggests the vehicle should'nt be depended on until you identify the problem - so have a good route round and you will find it.
You may need to lift your floor to see properly
1st time I did this it took a while whipping the seat and floor out
2nd time took 3 or 4 mins max - using an electric drill and socket
With the floor out you should be able to check the full system - dont forget the water pump
Chris

- (#9101) chris turner, 15 Jun 03 16:51

Hi Chris

“somewhere above the axle at the nearside front wheel”

This is the area where the expansion tank is, and if the expansion tank is quite full, then this could be the cause of your “leak”. When the engine is cold, first thing in the morning, the level in the tank should be near the low mark. With a hot engine, the level should be near the full mark. As the engine heats up, the coolant expands. Once the coolant has expanded enough to raise the pressure in the cooling system to 15psi, the radiator cap will start to allow coolant out to the expansion tank. If the cold level is above the full mark, then coolant expelled to it could overflow it, causing a puddle in the area you describe.

I would suggest you check the expansion tank level and correct it. Then check the expansion hoses. Gently twist the hose on each fitting. If the hose rotates on the fitting then its not sealed correctly, so move the clip that holds it on, and it should re seal. Also check the expansion hoses for cracks splits etc, and replace if necessary. Next I would strongly recommend replacing your radiator cap. Overheating can wreck the operation of the cap. Too little pressure, and your coolant will boil, too much pressure and leaks will appear all over the system. The latest radiator cap recommended by Bok members is the float type part number 16401 64501 (Ace Answers).

The other thing in this area which is worth checking, is the bottom radiator hose connection to the thermostat housing. If this is incorrectly fitted, loose or damaged, then the symptoms you describe would occur.

Are there any odd indications on your temperature gauge? This may help to source the cause if none of the above improve the leak.

Regards
dave Bright

- (#9102) dave Bright, 16 Jun 03 1:45

Thanks for advice. Have checked rad cap and it is well and truly shot. Will replace this afternoon and check hoses then monitor situation from there.

- (#9103) Chris, 16 Jun 03 2:29