Water pump? or Lower Radiator Hose?

[rapidoxidationman]

A closer look makes me think I just need to replace a short chunk of small diameter heater hose. Crossing my fingers that this'll prove to be a cheap (!!!) repair.

[rapidoxidationman]

Replaced the 5" piece of 3/8" heater hose that is the flexible part of the coolant return line from the turbocharger, put the cooling system back together, filled it up, and put the pressure tester on it. Pumped it to just under the cap pop pressure of 15#, and it seems like it's holding. Now it's lunchtime.

[jbplock]

Rapid,
After reading about your experience with the Turbo coolant line hose I'm thinking a preventative maintenance action might be to change them on my 03 LB7 - one near the water pump and one at the turbo. It wouldn't be fun to have one fail when towing my 5th wheel on a hot day. And I might as well replace the other hoses too. Back in the day it was common practice to replace hoses periodically to prevent failures. I was curious why modern hoses seem to last much longer and found the following info in the following Consumer Reports Article.

https://www.consumerreports.org/car-...lts-and-hoses/

“Experts recommend, however, that all hoses be replaced at least every four years or when one fails. Always use replacement hoses designed to fight ECD. Trademarks will vary among hose manufacturers. (Gates uses "ECR" for Electro-Chemical Resistant). Look for a "Type EC" label on the hose or its packaging. That is a Society of Automotive Engineers standard signifying "electrochemical." Most vehicles built after 1993 come with ECD-resistant hoses.”

And here’s another link with more detail on ECD

http://www.highwaystars.net/blog/wha...radation-mean/

Anyone have thoughts on replacing hoses as a preventative maintenance action?

[More Power]

Anyone have thoughts on replacing hoses as a preventative maintenance action?

Generally, it's heat that contributes most to a coolant hose deteriorating over time. The top radiator hose, for example, usually needs to be replaced about twice as often as the bottom hose. So, the trick is to locate the hoses that see the most heat, and change those more frequently.

Could be that the small coolant hose on the turbo sees more heat.

I know that GM went to using a blue silicone hose for the top heater core hose on the 6.5L diesel. That heater core hose lies close to the turbo exhaust housing and downpipe. Just maybe, there's a blue silicone hose available for that Duramax turbo coolant line...

[rapidoxidationman]

Full disclosure:
During the head gasket replacement project I did on the truck a few years ago, I twisted the hell out of that turbo coolant return line that I just had to replace. I'm sure the stress that I put on it back then contributed to last week's issue. That said, the rubber was pretty soft when I took it out.