Heater Pipe Leak Help

[donerehart]

Fiat Team,
I need help once again... I have a small antifreeze leak where my heater pipe fastens to the water pump. I am afraid to tighten the two bolts anymore, and my previous attempts haven't stopped the leak. It only leaks a few drops, but it is getting annoying... Do I have to drain the whole system to replace the small gasket there, or is there a way I can keep the antifreeze from emptying itself If I try to take off the tube? Is there a product that I could apply to the seal on the outside without taking the tube off that would stop the leak? What are your thoughts?
Thanks,
Don

[baltobernie]

Wise of you not to crank the heck out of those tiny bolts; they will strip out or break easily. You're going to have to disassemble the joint, as the cooling system is under pressure when running, and no sealant on the outside will work. Yes, opening this joint will result in a good deal of coolant discharge; cylinder head, heater, etc. Why not take the opportunity to replace it all? You can install an inexpensive flushing tee (Search for topic) to make it easy to "burp" the system now and in the future. Don't forget the block drain on the right side of the engine, in addition to the radiator petcock.

The mating flange on the metal heater hose is easily bent, a common cause of leaks. After removal, dress this surface with a flat file. Ideally, the file should be wider then the flange and placed on the workbench. The pipe and flange is moved across the file surface until a uniform surface is revealed. A new gasket and thin coats of RTV complete the job. The torque on the two bolts is way low, something like 7 ft.lbs.

[azruss]

i use the following method for getting the flange flat. rather than a file, i have a table saw with a metal top. I put down a 3x18" piece of sticky back sandpaper, the kind you get at the autopaint supply store. this gives you a flat surface much larger than with a file. It is also faster than using a file. I would use a 120-180 grit

[So Cal Mark]

once you get the flange flat it's important to use the bracket that supports the pipe in the middle. Otherwise the pipe will vibrate and flex and bend the ears on the flange again. I'd use some rtv sealant on the flange along with the paper gasket.

[donerehart]

Thanks for all your help and ideas - spectacular as usual! Unfortunately, I don't have that bracket in the middle for support...probably part of the reason for the problem. Does anyone have an extra one of those laying around?

[azruss]

it is easy to fabricate your own with plumbers tape or a metal conduit clamp

[rlux4]

You're lucky it's bad enough to leak. I had a small leak there but it wasn't bad enough to drip so I could see it. What happened is, because it's on the suction side of the water pump, I was sucking in air and displacing coolant out the over flow bottle. It was a major headache until I tracked down the problem. And the reason it happened is just as Mark says; a PO had cut the support strap and it bounced around until it failed at the flange. I staigthened it out, no problem, and now use a conduit clamp as Russ suggests to support it. It's been on there over two years and 12,000 miles with not problem.
Ron