740 Anti freeze leak

The hoses aren't too hard to replace, I've done it on the side of the road in the middle of nowhere in Alberta in the winter, pays to replace them pre-emptively when you have a nice warm garage. A trick I've used to track down the leak is to unplug the overflow hose from the radiator, plug the nipple on the radiator with a scrap of hose and a bolt or something, and then use an air compressor connected to the hose to pressurize the cooling system to about 5 psi. Don't go too high or you'll make a leak where there isn't one, but this allows you to simulate operating pressure without having the engine hot so you don't burn your hands on the exhaust manifold or get sprayed with scaulding hot coolant. You'll probably see coolant dripping or spraying from somewhere as soon as you pressurize it, should be a simple matter to feel around and find out where it's coming from.

The manifold does not need to come off. If the pipe from the pump is metal make sure that it is integral and not leaking due to rust from inside. It is most likely a leak from the heater pipes before they enter the bulkhead.

Cheers, Peter.

Thanks for the sugestion, I will get the hoses from FCP Groton, and replace them anyway. and will build some contraption to pressurize the cooling system.

Thanks

Arnold: Get a spare cap off a Volvo brake reservoir it will fit on the radiator reservoir. Go to the parts store and get a screw type valve stem, drill the proper sized hole in the cap and install the stem on the brake cap. Use this to pressurize the cooling system. Use a bicycle hand pump, 5 to 7 lbs should be enough to check for leaks.

Harold

Another trick you can use for that is go to a scrapyard and get a coolant resivoir cap, drill a hole in it and glue in a tire valve which you can get anywhere that sells bicycle or car parts. Then you can pump it up with a simple tire pump if you don't have an air compressor.

Oops, I should have read that post before I replied to the other.