Life Span of Hose?

Is there a general rule of thumb of when you should change hoses, specifically on the fresh water cooling components? In the engine room the other day and squeezed the hose from the thru-hull to strainer on the genset. Felt crunchy, so will be pulling it to replace. All others felt and look ok. Thoughts?

Mechanics and engineers have told me that the average working life of ANY hose is about 10 years, because as rubber and plasticizers age they dry out, become hard and brittle and prone to cracking. You can start to see signs of it (that "crunchiness" you felt) in some hoses as early as 5 years. The above doesn't apply to sanitation hose permeation...they can stink even though still structurally sound.

Yeah, the rule of thumb is about every 10 years for coolant hoses and less than that for high pressure lines like oil or transmission lines as I recall.

Max Simmons said:

Is there a general rule of thumb of when you should change hoses, specifically on the fresh water cooling components? In the engine room the other day and squeezed the hose from the thru-hull to strainer on the genset. Felt crunchy, so will be pulling it to replace. All others felt and look ok. Thoughts?

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If one of the hoses feels crunchy, then ANY hose of similar (or older) vintage should be changed. I check mine regularly. A broken through hull hose will definitely ruin your day.

Ken

You know, now that I think about it, maybe it was 5 years for coolant hoses and 10 for hydraulic?

Hmmm...

Coolant hoses 5 to 10 year max, provided they are marine grade, gates, and check them in a regular bases. Hydraulic is based on psi rating, and marine industrial grade.

Last year changed the coolant which were 9 years after a couple had cracked marks and on blister. This year replaced hydraulic which were 20+ years old which were 3000 psi rated and replaced them with the same and they were still in good condition according the hydraulic shop. The bow thruster hydraulic hose are 25+ years old, rated 4000 psi. So for hydraulic depend of grade psi.

Sometimes the "crunchiness" is mineral plating inside breaking off when you squeeze it.

If you go past 5 years on any hose, coolant, steering, thruster, etc.. you need to turn in your trawler owners card.

How in the world can you allow ANY hose exist in your rig thats 5 YEARS OLD?!?!?!?!?!

:lol:

The PO of our boat did a survey at the request of the insurance company when he bought it and one condition of insurance was to have ALL hoses changes as they were all original, 1981, or about 30 years old. So to say hoses need to be changed every 5 years IMHO is pushing it especially for the majority of boats around me that are lucky to get 30 to 50 hours of use per year. Deterioration is usually apparent if checked regularly. Just my .02C or a nickel in Canada since pennies are obsolete.

LaBomba said:

...So to say hoses need to be changed every 5 years IMHO is pushing it especially for the majority of boats around me that are lucky to get 30 to 50 hours of use per year. Deterioration is usually apparent if checked regularly. Just my .02C or a nickel in Canada since pennies are obsolete.

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I have been on professionally maintained recreational boats and I know the hoses aren't replaced every 5 years and they look great on the outside. Wouldn't oil analysis pick up if the hoses were degarding from the inside? What about braided hose? How about a visual inspection? Are hoses date stamped when manufactured?

I'll say it here, the one who buys Hobo, there may be a few hoses that are older than 5.

what_barnacles said:

How in the world can you allow ANY hose exist in your rig thats 5 YEARS OLD?!?!?!?!?!

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I find it pretty easy actully.

I do have some hydronic heating hoses that should be replaced. Not looking forward to that job.

Hmmm. Looks like next year's boatyard visit will call for engine-hose (and belt) replacements, or at least close professional examination.

whoaaaa...who said hoses needed to be changed every 5 years?


Hoses undergo different kinds of service in terms of temp, content, bend torture, etc...


5 years is an aggressive PM program...nothing wrong with it other that tossing perfectly good hoses.


Like my survey...change the hoses...critical safety issue.


Well after 5 years and 10,000 miles and 2500 hours I changed them.


Despite surface cracks on bends, the hoses were still pliable, didn't leak and were still serviceable when I replaced them.


So much for surveyor expertise and insurance companies blindly following ignorant advice.


Know thy hose...what kind of service it need to provide, know the torture it undergoes and go from there.


Anyone that says a particular hose has a service life better know its type, application, torture effects, etc...otherwise they are a textbook type...not a real true blue operator.

I've seen bad hoses five years old and hoses in great shape 40yrs old. Just crawl around and look at them and give them a squeeze. Snug the clamps. If any are hard and brittle, soft and gooey, cracked or swollen, replace.

I replaced all the coolant hoses on my Cummins 450 right at 15yrs of age. All appeared in good shape. I was cleaning coolers so most of the hoses were off anyway.

My pickup truck is nearing 30yrs of age. Hoses original as far as I can tell. Hoses still look good and pass the squeeze test.

Ski in NC said:

I've seen bad hoses five years old and hoses in great shape 40yrs old. Just crawl around and look at them and give them a squeeze. Snug the clamps. If any are hard and brittle, soft and gooey, cracked or swollen, replace.

I replaced all the coolant hoses on my Cummins 450 right at 15yrs of age. All appeared in good shape. I was cleaning coolers so most of the hoses were off anyway.

My pickup truck is nearing 30yrs of age. Hoses original as far as I can tell. Hoses still look good and pass the squeeze test.

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Thank you, Ski! The voice of reason.

My pickup truck is nearing 30yrs of age. Hoses original as far as I can tell. Hoses still look good and pass the squeeze test.

Very few trucks have ever been sunk by a failed hose.

Peggie
http://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

Beware crunching the engine circ. water hoses.

On the suction side some may have springs inside to keep them from collapsing.

To the OP....

If you limit the scope of the question to coolant hoses, I think Ski and others gave reasonable operator with the experience of mechanical backgrounds opinions.

There is no definite shelf life, and even with an average of say 10 years, it does somewhat depend on the hose quality and application.

I have seen molded hosed that look and feel great for well over 10 years, where a straight hose bent in the application was severely cracking on the outside in far less.

So unless a hose you buy comes with a tag on it giving a lifespan, all you can do is guess and make up a PM program for replacement that you are comfy with.

My own personal one is short straight or molded hoses for coolant on a nice cool running Lehman. 10 years with obvious hard looks as they get over 6 or 7 years.

Even though my rebuild is only going on about 7 years old, one molded hose into a pretty good "U" looks like it is deteriorating faster than the straight piece just above it (cut from the same original hose). So it is getting replaced but all the other hoses around it are fine for 3 more years.

Other owners may think I am waiting too long, others may laugh at me. But in genersl, major operating fleets have been looking for ways to extend life cycles based on measurable factors rather than time. Installing expensive equipment to measure things such as vibration, temperature, etc are extending component life and saving money, just like oil analysis.

Going strictly by time is old school...it might be the best you have....but realistically, inspection and observing telltale signs of further life or deterioration of hose, and how critical the application is, isn't all that difficult either.

I once bought an old (1981) VW diesel pickup. With my son being a mechanic with a few years of experience at the time, I asked him to do a quick safety check.
One of the things he told me is that a certain coolant hose should be replaced (It was original and probably close to 20 years old).
So the next morning I was driving to work with the intention of stopping at the local NAPA to buy that hose and change it that night.
Guess what? The hose blew out on my way to work!!!
Moral of the story....listen to mechanics, sometimes they know what they are doing.

This is what worries me about engine hoses. This came from my Lehman 120. It's the hose that runs from the bottom of the expansion tank.
The impression is from being pressed against the engine block.
Luckily I replaced before it wore thru, but I never would have seen it.

Anti-freez needs to be changed more often than hoses.Every 3-5 years.

Some Mfg suggest flushing the cooling system before the change.

I would 2 part flush with the old hoses , rinse, rinse, rinse and only then install the new hose.

jleonard said:

This is what worries me about engine hoses. This came from my Lehman 120. It's the hose that runs from the bottom of the expansion tank.
The impression is from being pressed against the engine block.
Luckily I replaced before it wore thru, but I never would have seen it.

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Looks like a cheap standard hose to replace.

I have an old boat, and old engines from 1970.
I bought the boat in 1998.
I replaced a few hoses.
However most of the hoses are OEM original from 1970.

I have over the last 5 years rebuilt the engines, and all the hoses are just fine.
I have never seen the fantastic great old hoses from 1970 for sale anywhere.

Most do have the steel coil, some don't.
These good old hoses, you can see a spiral wound pattern in the rubber casing, and the surface has a rough texture pattern. And the rubber is not cracked, hardened, split, it is perfect.

Now get this, some hoses are not from 1970, newer design have a color stripe one then, and in some of those the outer rubber spli, like a rubber dry rot, yet the inner liner is perfect as is the steel coil.

So I got some cloth friction tape (Ace hardware $2 a roll) and overwrapped then and of course that sealed up the surface and they look great toot.

For example this, a newer hose was spplitting and another hose I wrapped with the friction tape. See the inner liner is fine, I do not want the outer case to fall apart so I wrapped them. I did this many years ago and they are still looking great.


For example this really old great quality hose on left side in perfect shape painted a little green from 1970

HeadMistress said:

My pickup truck is nearing 30yrs of age. Hoses original as far as I can tell. Hoses still look good and pass the squeeze test.

Very few trucks have ever been sunk by a failed hose.

Peggie
http://www.amazon.com/New-Get-Rid-Boat-Odors/dp/1892399784/
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

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Good point. One good way to handle this is to go around your boat and look at the hose and ask "what happens if this fails?" There will be some that could sink you, some that would cause an overheat, and then some that would not really matter. What consequences of failure should determine how proactive you are.

And then that leads to the importance of things like high water alarms and known functional and redundant engine alarms.

Ski in NC said:

Good point. One good way to handle this is to go around your boat and look at the hose and ask "what happens if this fails?" There will be some that could sink you, some that would cause an overheat, and then some that would not really matter. What consequences of failure should determine how proactive you are.

And then that leads to the importance of things like high water alarms and known functional and redundant engine alarms.

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Yup. Plus Knowing what to look for on a daily basis is essential. On my vessel the cost to do all hoses could easily top $10K. Not something to jump into without a reason.

Careful inspection rules IMHO. Thus far on 13 year old vessel 3 hoses have weeped and been replaced. Watching another 30 or so including exhaust. But some vessels and owners install bargain basement hoses that are bad from day one. That is a big issue to be concerned about when buying a foreign made vessel or hoses on a used vessel acquired from a Walmart special parts bin.

My hoses were all original equipment (15 years old when I bought the boat). I replaced all raw water hoses when I purchased the boat, as the rubber was obviously deteriorated on the wet exhaust hose. Last year I replaced all of the coolant hoses on the engine, none showed any sign of deterioration in any way.

I simply didn't want to deal with the issue of a foreseeable failure. I also had the injector hoses replaced just to head off any issues, being broken down in our short boating season doesn't work for me With all of the commercial fishing boats out there at the same time getting work done in any kind of a timely manner is pretty much impossible. No tow services either, so it's the ounce of prevention...

My plan is to use the wet exhaust hose as a guide as to when to renew the other raw water hoses again.

I have two Volvo cars, with the same engine. One is 2000, the other 2005. I replaced the spark plugs in the 05 last month. There is a blowby hose in under the top cover. It was rotted so badly that it came away in several pieces. I replaced it. The other car, the 2000, has the same mileage on it. I have owned both since new, garage kept together until we moved 2 yrs ago, both driven under the same lack of stressful conditions. I replaced the plugs in the 2000 this week, though there were no symptoms suggesting I should. I inspected the blowby hose. It looks like the new one I bought for the 05 last month, but is OEM, so 16 yrs old. I squeezed it. It will stay in place.
Go figure.

EVERY hose in my boat, not just the engine room is only 2 years old most of them will not be changed again under my ownership! Took a big bite out of refit budget, but now it will be the next guys problem. We have a 10 year plan.

And yes, every hose has a manufacture date stamped, it is intersting to see how old some are still in the store.

Boat US published an article entitled Don't Get Hosed by Busted Hoses a couple of years ago. It has some useful guidelines if you are in doubt.

I don't think most manufacturers list a replacement schedule, although Gates, in a self-serving manner (my opinion), suggests replacement every four years.

"A replacement interval of four years for all coolant carrying hoses -- especially the upper radiator, bypass and heater hoses. The incidence of hose failure increases sharply after four years for most vehicles."

In 2003, my 83 MB 300TD still had its original radiator and heater hoses when I sold it with 225k miles. The dealer still had not recommended changing them! Crazy.

My engines have 7 PSI pressure caps, the cars are 16 psi, so the hoses do not have as much pressure on them.

Despite the endless push for cheaper manufacturing and cheaper stuff, I see that the chemistry and technology of synthetics and plastics keeps getting better. Most of us are old enough to remember cracked tires, rock-hard hoses, crumbling plastic objects and car parts. Cotton-reinforced tires and hoses, rubber wiring insulation dropping off, silk- or cotton-wrapped wire insulation. That peculiar smell of old electronics.

I think we'll see much extended service lives of such stuff, even in our 30-40 year old boats. Of course, failure of hoses in the engine spaces while you're driving from the flybridge would be both inconvenient and probably late to diagnose before awful messes were created!