Hose Selection

[Ron Hill]

Guys : I posted this in reply to a long string of answers to "Overheating" posts and the "same colored hose as your engine", but thought it should be information that all should read. 

The problem that you get into is that a hose usually starts to break down from the inside and at the outside radius of a bend.  So you really don't know how good/bad old hoses really are.  I usually change out hoses about every 8-10 years, but you need to inspect each hose every season looking for cracks and chaff spots.

The factory tended to use the expensive wire reinforced hose for every connection (they buy in bulk).  That isn't necessary and in one case I know of may have been detrimental !!  You only need wire reinforced hose for connections that go INTO the suction side of a pump or the hose makes an acute turn roughly 45 degrees or more.  That insures the hose will not collaps from suction or be restricted inside by the bend. 
The hoses that go on the OUTPUT of a pump only need to be nylon reinforced.  There are some exceptions such as preformed hoses to make tight or screwy turnes, fuel rated hoses and exhaust hose that needs to be exhaust rated.  Most of the hoses wire/nylon need to be of high quality and temperature rated (heater) hoses.

The determinital wire hose I mentioned is the hose from the HX anti syphon to the nipple on the exhaust riser (raw water mixes with the exhaust gases).  After I replaced the factory wire reinforced hose with a nylon (MORE flexable) hose, I didn't have any more nipple welds cracking. Too much engine vibration transmitted thur that stiffer wire hose, I suspect !!!
     
A few thoughts