Engine hose (s) replacement schedule

This morning we were just underway (less than a 1 mile) when Lena noticed the engine alternator was reading about 1/2 of what it should and wasn't steady. She backed down to idle speed. On my way to check the engine room/alternator she said it was back to where it should be. I opened a floor hatch and saw immediately that the problem was the U shaped hose from the header tank to engine had split (FL SP135). We stopped, made repairs and 1/2 hour later we continued on. I had a spare hose and 1 gallon of antifreeze. My guess is the alternator reading was the result of antifreeze spilling onto the belt and making it slip. I know if we had engine cameras I would have seen it.

But my question is, how often should the engine hoses be replaced? I thought I had replaced them all and I may have, but we've had Hobo for over 8 years and so I was wondering is there a rule of thumb for pm instead of just waiting till one fails. Thoughts?

The hose and it's replacement are preformed so I'm not taking a straight section and trying to make that radius.

I replaced every hose when I bought Seaweed (seemed like cheap insurance)

And if one goes such as yours did, well, I'd do them all again. You're likely to find others bad on the inside...

When I did mine originally I was told "needless" and "they look fine" ... that was inaccurate. Two at bends had damage only visible on the inside.

I did the belt(s) too. Can't remember if it was one or two. It's been a while.

I think good, marine grade hose, like 250 series Trident or Shields can last 15 years or more. But a molded hose w/ only fabric braid like yours, should be changed when it first shows signs of swelling and softness like yours.

Different hoses of different uses and materials could have vastly different replacement schedules.

Also hoses that are formed bent tend to last longer than those tortured into unusual bends.

Any hose that starts very flexible that is getting hard should go.

Some hoses will develop surface cracks yet have many years of trouble free service life left in them..like my exhaust hoses that were recommended by the unknowing 5 years ago.

My concern is always hoses under more than a few psi pressure...those usually have bigger issues than those under suction, but fuel lines always need close attention.

One thing you should do, is stop using those cheap hose clamps.

I just replaced all hoses on both of my engines because most of them looked original. That U shaped hose doesn't even have braid in it so it makes sense it was the first to go.

Ken

I replaced all the hoses on my 1987 diesel in 2003 and then again last Fall. Neither time were any of the hoses bad, but the engine was out and it was easy to replace the hoses.

How about the hoses to and from the oil and transmission coolers?

Oil/tranny hoses are hydraulic wire wound. If hose shows no signs of corrosion or blistering from rusted wires, not brittle, ends not corroded, probably ok.

I replaced all the hoses on my cummins 450 this spring. It's 15yr old and all but a couple seemed in ok shape.

If they feel soft or hose clamp has dug into it, replace. If oil or fuel has dripped on them, replace.

Hand over hand and visual inspection probably will tell you if you need to replace.

Capt.Bill11 said:

One thing you should do, is stop using those cheap hose clamps.

Click to expand...

Mind posting a pic of a 'good' one?

Hoses under Suction? just saw a beautiful Hatteras destroy a Detroit because of a faulty raw water cooling suction line. 60,000 later he has two fresh engines to putt around with. I just replaced ALL of the water and coolant hoses on my 88 model. And as mentioned in previous post "looked" original. And of course "Looked" OK!
To your question. If you replaced it 8 years ago..you now have what is called an "Operating Experience". Use it to prevent failure at 8 years. Called Predictive Maintenance.
Great use of skills Lena, to notice the poor reading on the volt meter quickly enough to prevent over heat melt down! Good Job to the Cap'n.
Great thread. I saw very small leak on the underside of one of the coolant lines after a trip last fall. Close inspection found tiny cracks all around the cut end of the hose where it tied to the cooler. Changed them all.

American Diesel sell full hose sets for L120s, probably other models too.
For a quick fix, you can usually find an automotive hose with the right bend at a general auto parts shop, just cut off the bits you don`t need.

shufti said:

Mind posting a pic of a 'good' one?

Click to expand...

AWAB hose clamps are really expensive, but really good. We leave a bunch of lines underwater at work (intentionally! ) and these are the only ones we've found that last more than 6 months or so.

Someone did a house clamp review in a rag hauler mag once upon a time. ...let me see if i can find it. ...

Gabe n Em said:

AWAB hose clamps are really expensive, but really good. We leave a bunch of lines underwater at work (intentionally! ) and these are the only ones we've found that last more than 6 months or so.

Someone did a house clamp review in a rag hauler mag once upon a time. ...let me see if i can find it. ...

Click to expand...

+1 for the quality of AWAB S&S clamps.

Thanks.

shufti said:

Mind posting a pic of a 'good' one?

Click to expand...

See the difference?

BruceK said:

American Diesel sell full hose sets for L120s, probably other models too.
For a quick fix, you can usually find an automotive hose with the right bend at a general auto parts shop, just cut off the bits you don`t need.

Click to expand...

There are only two molded hoses on a 120/135 as I recall. All the rest are straight. And you can match up the molded ones to other hoses you can find in an auto parts store in a pinch. You just cut off the excess hose to match the shape you need. In most cases doing that saves you money over buying the replacement hose kits people sell.

The ADC hose kit is cheap. And zero running around to find what you need.

Yeah but sometimes you need one/them now. Or you are out of the country.

The difference between a good stainless steel clamps and one that is not is a good one has no thread holes the bad ones you can see through the clamp where the adjustment threads are.