My truck is 5.5 years old with 58k miles - it still has the original coolant hoses. I have replaced the coolant every 18 months regardless of mileage. Coolant used has been Fleetguard Complete 50-50 premix. I have researched this issue and was under the impression that hoses needed to be replaced when they felt hard and brittle; this aside from the obvious cracks, bulges etc. A friend, who is also a mechanic (not diesel), tells me that I should be looking for a "too soft" hose condition; now I'm confused. Is it possible that both conditions could be applicable? The hoses ( radiator and heater) still feel fine to me and do not have any appearance blemishes but to be on the safe side I will replace them as well as any other hoses, belts next spring.

 

I personally have never found a set hard and brittle. They always get spongy and bulged out next to the pump or radiator before they blow to me.

FWIW, my 97 appears to have the original hoses and they seem OK, I am going to put new ones on when I replace the radiator soon. No sense in chancing it for 40 bucks worth of hoses.

 

I also have never had any coolant hoses get hard and brittle on any vehicle I have ever owned. Soft and spongy yes. I replaced mine at 140ish k and while they seemed ok on the truck the lower pass side was very soft and spongy once I got it off. The upper one felt ok on the truck as well but once off was not real good either, not nearly as bad as the lower one though. When I first started the project I thought maybe I was premature doing it but after looking at the hoses as I took them off I was very glad I did it. They may have lasted a long time but they were definitely not in good shape.

Now fuel lines, vacumn lines etc can get hard and brittle.

 

I just carry spares and some coolant.Its time to change them when they get a hole in them I guess.

 

About the only time they would ever get hard and brittle would be if the vehicle sat unused for a very long time, and they would dry rot from the outside in.

Soft and spongy would be the normal wear and tear on the hoses.

 

leave em alone... radiator hose usually don't give problems until vehicle gets 10+ years old.

when a vehicle gets to be 20+ years old, I'd replace ALL hoses. a little bypass hose can take you down just as good as say a larger upper radiator hose.

sold a butt loads of auto parts and usually didn't get calls for hoses until vehicles got 15+ years old.

 

wrap your hand around the hose then take your thumb and press hard into the hose,and bend up at the same time. if you hear/feel the threads/cords in the hose give way they are toast and it needs to be replaced, if you dont hear/feel them break they are fine. it is very obvious when you do this. 20yrs as a mechanic and this test has not failed me yet

 

Just replace mine with 400K and 9 years old. They still looked to be in good shape.