Replace Coolant Hoses Due to Age?
Thread Starter
Intermediate
Joined: Feb 2020
Posts: 47
Likes: 10
Replace Coolant Hoses Due to Age?
Trying to gain some wisdom from the community. Tried searching but haven't found a newer thread on the subject. I have a 2003 Z06 with 29k miles. Stock everything. Going to be replacing the radiator, upper hose, and lower hose.
Question: Given the car is nearly 20 years old should I replace every coolant hose due to age?
Background: I bought the car May of this year and immediately changed all fluids. Car had one coolant flush in its life in 2010. So when I got it had 10 year old Dexcool. Drained clean and didn't see any problems.
Typical Use: I pretty much use this car as a 3 season daily and also did 3 autocross events this year. Plan on competing more next year.
Thanks!
Question: Given the car is nearly 20 years old should I replace every coolant hose due to age?
Background: I bought the car May of this year and immediately changed all fluids. Car had one coolant flush in its life in 2010. So when I got it had 10 year old Dexcool. Drained clean and didn't see any problems.
Typical Use: I pretty much use this car as a 3 season daily and also did 3 autocross events this year. Plan on competing more next year.
Thanks!
Popular Reply
Nov 19, 2020, 08:10 PM
Drifting
Joined: May 2007
Posts: 1,552
Likes: 324
From: Mid Ohio
In the 90s I was a OEM water pump engineer. And part of my job was to design hoses and their connections. Including those constant tension clamps everyone hates.
Well... technically from the moment a pure rubber product leaves the vulcanizer, those rubber products have a life of 4 yrs. So... what we did was make synthetic rubber blends and add layers that serve different purposes.
Automotive hoses generally have three parts to make them last much longer. 1. the outer sleeve that resists UV and chemicals. 2. the mesh / binder that keeps a hose from expanding and bursting. 3. the inner sleeve that has high chemical resistance.
So in my garage.... here is what I do. I look for two things before I call a hose bad. 1. Are the ends where the clamps are located... hard? Like you can barely dig your fingernail in it? 2. If there is any sign of a hose expanding beyond its normal size.. (especially just off the connections where they get flexed the most).. its bad.
Generally speaking on a garage queen (corvette)... 20-25yrs is when you'll start to see them failing.
And in a daily driver.. about 150k miles and 12-15yrs is their normal life span.
Well... technically from the moment a pure rubber product leaves the vulcanizer, those rubber products have a life of 4 yrs. So... what we did was make synthetic rubber blends and add layers that serve different purposes.
Automotive hoses generally have three parts to make them last much longer. 1. the outer sleeve that resists UV and chemicals. 2. the mesh / binder that keeps a hose from expanding and bursting. 3. the inner sleeve that has high chemical resistance.
So in my garage.... here is what I do. I look for two things before I call a hose bad. 1. Are the ends where the clamps are located... hard? Like you can barely dig your fingernail in it? 2. If there is any sign of a hose expanding beyond its normal size.. (especially just off the connections where they get flexed the most).. its bad.
Generally speaking on a garage queen (corvette)... 20-25yrs is when you'll start to see them failing.
And in a daily driver.. about 150k miles and 12-15yrs is their normal life span.
.
Joined: Apr 2013
Posts: 5,035
Likes: 1,156
From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
Why are you going to replace ONLY the upper and lower hose? The other ones are not lifetime hoses and you said your going to autocross more this season
Racer
Joined: Jul 2019
Posts: 377
Likes: 116
From: MN
When I purchased my '02 last August (2019) it had 17,800 miles and original Dex Cool. I was a little nervous but it came out just fine when I changed it. This year I put new water pump gaskets in and was going to replace hoses while apart, but they still looked brand new. Guess that puts me in the still original club.
Last edited by roegs; Nov 19, 2020 at 08:47 PM.
Thread Starter
Intermediate
Joined: Feb 2020
Posts: 47
Likes: 10
No leaks out of the radiator but haven't really driven it since this happened. I don't want to take any chances so at a minimum doing the radiator and upper and lower hoses. Just thought I'd ask about the other hoses while I have things apart.
Smoken1, do you replace hoses as a preventative when you have a dual duty car? I come from the BMW world where the cooling systems were horrible and things would fail if you looked at them wrong. So I just got used to replacing cooling components on short intervals as preventative.
Drifting
Joined: May 2007
Posts: 1,552
Likes: 324
From: Mid Ohio
In the 90s I was a OEM water pump engineer. And part of my job was to design hoses and their connections. Including those constant tension clamps everyone hates.
Well... technically from the moment a pure rubber product leaves the vulcanizer, those rubber products have a life of 4 yrs. So... what we did was make synthetic rubber blends and add layers that serve different purposes.
Automotive hoses generally have three parts to make them last much longer. 1. the outer sleeve that resists UV and chemicals. 2. the mesh / binder that keeps a hose from expanding and bursting. 3. the inner sleeve that has high chemical resistance.
So in my garage.... here is what I do. I look for two things before I call a hose bad. 1. Are the ends where the clamps are located... hard? Like you can barely dig your fingernail in it? 2. If there is any sign of a hose expanding beyond its normal size.. (especially just off the connections where they get flexed the most).. its bad.
Generally speaking on a garage queen (corvette)... 20-25yrs is when you'll start to see them failing.
And in a daily driver.. about 150k miles and 12-15yrs is their normal life span.
Well... technically from the moment a pure rubber product leaves the vulcanizer, those rubber products have a life of 4 yrs. So... what we did was make synthetic rubber blends and add layers that serve different purposes.
Automotive hoses generally have three parts to make them last much longer. 1. the outer sleeve that resists UV and chemicals. 2. the mesh / binder that keeps a hose from expanding and bursting. 3. the inner sleeve that has high chemical resistance.
So in my garage.... here is what I do. I look for two things before I call a hose bad. 1. Are the ends where the clamps are located... hard? Like you can barely dig your fingernail in it? 2. If there is any sign of a hose expanding beyond its normal size.. (especially just off the connections where they get flexed the most).. its bad.
Generally speaking on a garage queen (corvette)... 20-25yrs is when you'll start to see them failing.
And in a daily driver.. about 150k miles and 12-15yrs is their normal life span.
Last edited by wydopnthrtl; Nov 19, 2020 at 08:16 PM.
.
Joined: Apr 2013
Posts: 5,035
Likes: 1,156
From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
I drove over an unmarked exposed manhole cover that ended up bending my radiator support and the bottom of the radiator (slightly). This area of the road was not marked by construction signs and they milled the road down right before the exposed cover (road dropped in elevation right before the manhole). Had the road stayed level the car would have cleared the manhole fine but with the drop in elevation it clipped my radiator support and bent it. Fighting with the township on this. All of this happened less than 15 mph
No leaks out of the radiator but haven't really driven it since this happened. I don't want to take any chances so at a minimum doing the radiator and upper and lower hoses. Just thought I'd ask about the other hoses while I have things apart.
Smoken1, do you replace hoses as a preventative when you have a dual duty car? I come from the BMW world where the cooling systems were horrible and things would fail if you looked at them wrong. So I just got used to replacing cooling components on short intervals as preventative.
No leaks out of the radiator but haven't really driven it since this happened. I don't want to take any chances so at a minimum doing the radiator and upper and lower hoses. Just thought I'd ask about the other hoses while I have things apart.
Smoken1, do you replace hoses as a preventative when you have a dual duty car? I come from the BMW world where the cooling systems were horrible and things would fail if you looked at them wrong. So I just got used to replacing cooling components on short intervals as preventative.
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Thread Starter
Intermediate
Joined: Feb 2020
Posts: 47
Likes: 10
Thanks Wydopnthrtl! That was very informative and I learned something new. I'll take my time and inspect each hose using the criteria you listed. Thank you Smoken1 for letting me know when you replaced yours too. Now I'm leaning towards just biting the bullet and doing all the hoses. My car is going to be down until Spring so plenty of time to drop the radiator support and inspect or replace the hoses.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
As a point of reference, I have a 2003 Tahoe that I purchased new in December 2002. I have changed the coolant every 5 years and now have 125K miles on the vehicle. I am still on the original hoses. They all look good per the tests mentioned in a post above. The only hose that can't be checked easily is the one going to the rear heater but the one end looks good. I can remember when it was common to replace antifreeze every two years and several hoses at the same time but now hoses just seem to last a lot longer.
Bill
Bill
Race Director
Joined: Oct 2004
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I should've added it is coming up on 116,000 miles. I've been tempted to buy new, but originals are not too soft in any areas, no bulges, and not too hard anywhere. I'll run them to at least 125,000 miles, or failure, whichever comes first......
Drifting
Joined: May 2008
Posts: 1,695
Likes: 490
From: Denver, NC
To anyone running coolant for a decade or more (can't believe I even an typing that), you might want to test the coolant with a multimeter. Anything above .3V at rest means the coolant is holding a charge. Anything above .3V running at 2,000 rpm is a fail as well. When the coolant has voltage above .3V, you are on the road to suffering a failure due to electrolysis.
Thread Starter
Intermediate
Joined: Feb 2020
Posts: 47
Likes: 10
Thank you for all the replies everyone! I will take this weekend to check every hose before I order parts.
Good point, Ed Ramberger. I should have checked the charge on the 10 year old Dexcool before I drained it just for science sake.
Good point, Ed Ramberger. I should have checked the charge on the 10 year old Dexcool before I drained it just for science sake.
Team Owner
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY
I'm one of those "just because" type of people, who DREADS the thought of being stranded by the side of the road. I'm the original owner of my just under 30,000 mile, '01 C-5. I've changed the coolant 3 times, at least what will drain out from the tank and radiator, and replaced the hoses with silicone hoses, about 5 years ago.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
To anyone running coolant for a decade or more (can't believe I even an typing that), you might want to test the coolant with a multimeter. Anything above .3V at rest means the coolant is holding a charge. Anything above .3V running at 2,000 rpm is a fail as well. When the coolant has voltage above .3V, you are on the road to suffering a failure due to electrolysis.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
I just read your response to me. Your OP did NOTday anything about long trips. I'll be a hypocrite here, and say you should replace them soon. The hypocrisy manifests as I drove my car from Michigan to Florida a month ago. 1,250 miles. I SHOULD get new hoses when depending on 20 year old hoses in the dark of night. This is similar to " Do as I say, not as I do!!! LOL.......
Team Owner
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY