Radiator hose replacement on C12

[Paulhowell]

During a recent inspection, I noticed my lower radiator hose had a slight leak where it transitions to the metal pipe. The metal pipe is also fairly rusty so I would like to replace both the upper and lower rubber hoses and paint both of the metal tubes. When I disconnect the lower hose, how much coolant will run out? After I replace the rubber hoses and paint the metal pipes, I will install the old coolant since it just tested good about two months ago. Is there a procedure to bleed the system?  I was going to use a suitable high heat rustolem type paint, is that okay? Does anyone have any good recommendations for replacement hoses?  I would greatly appreciate any advice. My coach is a 1999 Patriot Thunder 425 with a C12. Thanks!
Paul

[Gerald Farris]

Paul,
If you drain your cooling system, you will get 8 to 10 gallons of coolant out, but if you just disconnect the hose you will get less, depending on how much the hose is above the bottom of the radiator. Your choice in paint sounds very adequate.

If you can stop the leak by tightening the hose clamp, and you are nearing coolant change time, it would be easier to change the hoses and repaint the needed pipes at that time.

Gerald 

[Paulhowell]

Thanks Gerald!

[Doug Allman]

Paul, When I replaced all the hoses on our 2004 Marquis C-12 I changed the clamps to the T-Bolt type. They are more expensive but you can get a much better seal with them. I would imagine most parts stores have them but I purchased mine thru NAPA as well as the hoses.

[Larry Dedrick]

Paul
   I highly recommend to use a rust preventative paint called POR15. I have used this product on metal and it will hault any rusting and it bonds permanently to metal. I applied it to my coolant pipe after prepping it, whereas the rustoleum I used prior was severely pitting a month later. once you apply POR15, it is bonded to the metal like no other. POR15 can be found on-line
   Good Luck