Curious coolant leak

[whitespider]

Hi Folks,
Another problem has appeared on my car, this one has got me stumped. I have been away on holiday with the surf. It has had two big trips into the highlands and has developed a leak.
There is normally quite high pressure in the top radiator hose, I check this after every drive after head refit.
I noticed that the hose was very soft so I looked underneath to find a puddle forming.
The engine was not running.
I topped up about half a litre- a litre. As the engine cooled the leak stopped.

I then started it up the following day to drive to a garage to get some radweld. Fine when running then the leak appeared after I stopped.
Got most of the radweld in, heated the engine up and left to cool.

Following day no leak. Went for a drive, stopped and out came the coolant about 500mls max. Topped up at rad cap, noticed very little in expansion tank. Drove on for 100 miles, stopped no leak.

I cannot work out why aleak would not be worse under pressure and why it stops when running and starts when cooling and stops when cold.

I don't think the radweld has done anything.

Any pointers or opinions?
I am going to get it checked out but thought I would ask the oracle first.

cheers
Ronnie

[marky]

Hi Folks,
Another problem has appeared on my car, this one has got me stumped. I have been away on holiday with the surf. It has had two big trips into the highlands and has developed a leak.
There is normally quite high pressure in the top radiator hose, I check this after every drive after head refit.
I noticed that the hose was very soft so I looked underneath to find a puddle forming.
The engine was not running.
I topped up about half a litre- a litre. As the engine cooled the leak stopped.

I then started it up the following day to drive to a garage to get some radweld. Fine when running then the leak appeared after I stopped.
Got most of the radweld in, heated the engine up and left to cool.

Following day no leak. Went for a drive, stopped and out came the coolant about 500mls max. Topped up at rad cap, noticed very little in expansion tank. Drove on for 100 miles, stopped no leak.

I cannot work out why aleak would not be worse under pressure and why it stops when running and starts when cooling and stops when cold.

I don't think the radweld has done anything.

Any pointers or opinions?
I am going to get it checked out but thought I would ask the oracle first.

cheers
Ronnie

Have you checked all Hose clips & around water pump also check the 2 metal pipes that run underneath to the rear heater.

[whitespider]

The leak is visible as droplets dripping from bottom of radiator, haven't had chance to have a close look. The radiator was put in new two months ago.
Not saying its definately the rad but thats where the drip is visible.

Could it be anything else?

[da SLUG man]

did you have the air con running?

that leaves a little puddle under the car when you stop.

[whitespider]

Pretty sure it was off, no gas in it at moment.

[Vagrant No2]

I have changed water pumps before as they had leaked only with engine off . Due to the seal going hard .

Worth checking around that area.
Rick

[Guest]

Also expansion and contraction with heat / cold can sometimes cause this, it will either leak when cold or leak when hot, depends on the nature of the joint that is leaking.

Cheers

[stimpy30]

hi as vagrant says water pumps mostly leak worse when engine is turned off as its sat flat against seals as apposed to spining on it . 1st with engine turned off try water pump spindle for play then 2nd look round water pump for small circular hole and watch carefully as this is where water drips out if seal is broken no cure for this though sept new water pump so make sure first

[whitespider]

Hi folks'

The leak is definately from the radiator. Replaced the water pump and removed radiator, the rad is away getting pressure checked and the leak mended.

The car developed a very worry problem, the night before I took it to the garage went for a drive and returned with the leak seemingly worse, but the worrying thing was the rad hoses were well inflated.
The pressure in the coolant system seems to be rising. The head had been tested prior to the leak and it wasn't cracked, had new rad and new rad cap fitted at same time as head refit.
There is no coolant expulsion from the expansion tank, no steam from rear end, no oil and water mix and the temp gauge is normal.

Why are the pipes so pressurised????

The heaters work hot on driving but run cool on stationary.

Could it be a faulty rad cap or air lock?

Could the leak have something to do with it?

Or is it another head/block problem?

The only difference between having normal pressure and inflated hoses was I left out the stat when refitting head, put the stat back in just before the rad sprung a leak, and the pressure rose.

Anyone know what sort of pressure should be on the hoses etc.

Any info welcome, as I'm truly paranoid now.

cheers Ronnie

[Koi]

Hi folks'

The leak is definately from the radiator. Replaced the water pump and removed radiator, the rad is away getting pressure checked and the leak mended.

The car developed a very worry problem, the night before I took it to the garage went for a drive and returned with the leak seemingly worse, but the worrying thing was the rad hoses were well inflated.
The pressure in the coolant system seems to be rising. The head had been tested prior to the leak and it wasn't cracked, had new rad and new rad cap fitted at same time as head refit.
There is no coolant expulsion from the expansion tank, no steam from rear end, no oil and water mix and the temp gauge is normal.

Why are the pipes so pressurised????

The heaters work hot on driving but run cool on stationary.

Could it be a faulty rad cap or air lock?

Could the leak have something to do with it?

Or is it another head/block problem?

The only difference between having normal pressure and inflated hoses was I left out the stat when refitting head, put the stat back in just before the rad sprung a leak, and the pressure rose.

Anyone know what sort of pressure should be on the hoses etc.

Any info welcome, as I'm truly paranoid now.

cheers Ronnie

could well be an airlock, had my heaters work whilst driving and cooled down when stationary.
Let engine cool right down (best first thing in morning) both heaters to hot setting, remove rad cap and refill/top up as required. Start up and give a good couple of blips on the loud pedal, top up again and repeat several times until it won't take any more.
Take for short drive and check level again, keep an eye on it for the next few days as mine seemed to move some more air a couple of days later, since then fine.

[stara]

Hi folks'

The leak is definately from the radiator. Replaced the water pump and removed radiator, the rad is away getting pressure checked and the leak mended.

The car developed a very worry problem, the night before I took it to the garage went for a drive and returned with the leak seemingly worse, but the worrying thing was the rad hoses were well inflated.
The pressure in the coolant system seems to be rising. The head had been tested prior to the leak and it wasn't cracked, had new rad and new rad cap fitted at same time as head refit.
There is no coolant expulsion from the expansion tank, no steam from rear end, no oil and water mix and the temp gauge is normal.

Why are the pipes so pressurised????

The heaters work hot on driving but run cool on stationary.

Could it be a faulty rad cap or air lock?

Could the leak have something to do with it?

Or is it another head/block problem?

The only difference between having normal pressure and inflated hoses was I left out the stat when refitting head, put the stat back in just before the rad sprung a leak, and the pressure rose.

Anyone know what sort of pressure should be on the hoses etc.

Any info welcome, as I'm truly paranoid now.

cheers Ronnie

my rad pipes were worryingly hard (snigger) when i first had my truck, and are still the same 18months on with no probs, you def have an airlock, try parking uphill (or on ramps) overnight to encourage the moving airbubble to the 'top' of the system. and fill using the usual method described on the forum.