Calorifier piping

[Meps1983]

Evening folks.
Just a quick one really regarding a perished hose really. One of the hoses coming from my engine has perished/cracked where it goes Into the calorifier unit itself. This was flagged on the survey when we purchased and I've only just got onto doing the repair as its not been leaking.
Question is... if I remove the damaged pipe, remove an inch or so and replace it. Will I cause air pockets within that cooling circuit that will need bleeding of some kind? I'm new to these water heaters and larger engines. My engine is a mercruiser 350 mag mpi and it'd an attwood water heater. I'm not sure if the pic has worked but it's the pipe labeled "C" on the unit and is clearly perished. Any guidance would be much appreciated thanks.
Ben

 

[BB1]

It will be fine.

 

[Plum]

Evening folks.
Just a quick one really regarding a perished hose really. One of the hoses coming from my engine has perished/cracked where it goes Into the calorifier unit itself. This was flagged on the survey when we purchased and I've only just got onto doing the repair as its not been leaking.
Question is... if I remove the damaged pipe, remove an inch or so and replace it. Will I cause air pockets within that cooling circuit that will need bleeding of some kind? I'm new to these water heaters and larger engines. My engine is a mercruiser 350 mag mpi and it'd an attwood water heater. I'm not sure if the pic has worked but it's the pipe labeled "C" on the unit and is clearly perished. Any guidance would be much appreciated thanks.
Ben

If the end is perished then the rest of the hose will be deteriorating too. Not worth the risk of a burst hose while at sea leading to an overheating engine. If it was mine I would replace both hoses and check all other engine coolant hoses very carefully. As your hoses are relatively horizontal there is little chance of a trapped air pocket.

www.solocoastalsailing.co.uk

 

[simonfraser]

i'd be ok with shortening the hose as in pic

what is the other end of same hose like ?

 

[PaulRainbow]

Evening folks.
Just a quick one really regarding a perished hose really. One of the hoses coming from my engine has perished/cracked where it goes Into the calorifier unit itself. This was flagged on the survey when we purchased and I've only just got onto doing the repair as its not been leaking.
Question is... if I remove the damaged pipe, remove an inch or so and replace it. Will I cause air pockets within that cooling circuit that will need bleeding of some kind? I'm new to these water heaters and larger engines. My engine is a mercruiser 350 mag mpi and it'd an attwood water heater. I'm not sure if the pic has worked but it's the pipe labeled "C" on the unit and is clearly perished. Any guidance would be much appreciated thanks.
Ben

It would be very foolish to just shorten that hose, it has perished. Replace both hoses and check all of the others, as post #3 advises.

 

[simonfraser]

it has perished where it has been stretched and heated by the calorifier
by all means replace all the hoses in the boat

 

[PaulRainbow]

it has perished where it has been stretched and heated by the calorifier
by all means replace all the hoses in the boat

How was it heated by the calorifier ?

It's one of the engine coolant hoses, IT heats the water in the calorifier.

If it leaks, it pumps your engine coolant into the bilge.

1/2" heater hose costs £3.65 a metre. A little cheaper than a head gasket, or an engine.

 

[QBhoy]

Hi. I’d personally just replace the two hoses, to be honest.
They shouldn’t be too affected by the heat. They provide the heat to the unit when not on electric, as you’ll know. There will be about 160oF running through the supply hose at least. Anyway…easy job to replace. They just come from and to fittings, just behind the t stat and on top of the water circ pump, as you’ll know.
Slightly off topic, but how are you getting on with the 350 mpi ? Great engines as long as you keep the distributor cap fresh. Absolutely the biggest issue they have. Great ti have the smart craft ability, whether that be the dash gauges or the excellent and very cheap vessel view mobile device, that shows an incredible amount of pin point detail on your phone or tablet. Great to know your fuel consumption, range and best cruise speed etc. all the fault descriptions too, that you’d normally need a dealer to plug in diagnostics to reveal.
I’ve got one in an 18ft boat. So powerful and efficient too.

 

[Boat2016]

i'd be ok with shortening the hose as in pic

what is the other end of same hose like ?

Shortening it would mean trying to get the inside of the hose that’s had coolant through it to seal when it’s likely to be very slippery, theres a good reason why hydraulic hoses can’t be cut back and shortened after use and I would take the same view here taking into account the consequences if it then failed.

 

[Meps1983]

And this is why I LOVE this forum! Varying answers all with valid reasons. I've checked the other end of the damaged hose on the engine and it's in perfect condition as is the other hose.
I think (newbie) the damaged hose is the hotter of the 2 that comes from the engine, so it makes sense to replace.
Where can I buy the hose from as you were saying Paul? Is it simply a case of pulling the old one off and new one back on or will I need to bleed/purge the air out somehow as I originally posted? Again sorry for any silly questions guys!!

Qbhoy- I've only had the boat for a year but so far I've zero complaints regarding the engine thus far, she runs/purs and starts perfectly
When when you say keep the cap fresh do you mean replace periodically like a service or clean regularly? I had it serviced on Tuesday and all went well so now just waiting for the sun like the rest of us!
what's is this "smart craft ability" witchcraft tou speak of?

Once again thanks for you replies, the knowledge I'm gaining from this site is on another level! Cheers Ben.

 

[PaulRainbow]

Apologies, i meant to post a link in my previous post 13mm 1/2" EPDM Car Heater Rubber Hose (SAEJ20R3)

Looks a good price to me.

Just undo the clips and pull the hoses off, that might be easier said than done, in which case slice the hose with a Stanley knife. You'll find the new ones will go one easier if you smear a little washing up liquid in the ends of the hoses. Should be no need to bleed, run the engine at idle with the filler cap off and keep an eye on the coolant level, top up with pre-mixed coolant or 50/50 antifreeze and water.

That hose is perished, nothing to do with getting hot, it's designed to withstand coolant temperatures, it's a heater hose (clue in the name )

I would most definitely change both hoses. If one has perished the other could be the same age and on its last legs, two new ones and you know exactly what you have and won't be risking an overheated engine.

 

[Meps1983]

For the money it costs to replace the hose I think I'll swap out the pair, for peace of mind.
I should have mentioned earlier that I'm on a bravo 3 outdrive which means my engine is seawater cooled. I'm pretty sure (not 100%) that my mag doesn't have coolant to top up!? Does that change anything in regards to a simple swap over of the hoses? Thanks again for your time .

 

[PaulRainbow]

For the money it costs to replace the hose I think I'll swap out the pair, for peace of mind.
I should have mentioned earlier that I'm on a bravo 3 outdrive which means my engine is seawater cooled. I'm pretty sure (not 100%) that my mag doesn't have coolant to top up!? Does that change anything in regards to a simple swap over of the hoses? Thanks again for your time .

Swap the pipes and start the engine, keep an eye on the water coming out the back and the temp, rarely a problem.

 

[QBhoy]

And this is why I LOVE this forum! Varying answers all with valid reasons. I've checked the other end of the damaged hose on the engine and it's in perfect condition as is the other hose.
I think (newbie) the damaged hose is the hotter of the 2 that comes from the engine, so it makes sense to replace.
Where can I buy the hose from as you were saying Paul? Is it simply a case of pulling the old one off and new one back on or will I need to bleed/purge the air out somehow as I originally posted? Again sorry for any silly questions guys!!

Qbhoy- I've only had the boat for a year but so far I've zero complaints regarding the engine thus far, she runs/purs and starts perfectly
When when you say keep the cap fresh do you mean replace periodically like a service or clean regularly? I had it serviced on Tuesday and all went well so now just waiting for the sun like the rest of us!
what's is this "smart craft ability" witchcraft tou speak of?

Once again thanks for you replies, the knowledge I'm gaining from this site is on another level! Cheers Ben.

Hi Ben
I’d definitely keep a spare onboard for sure especially if you are in the sea. They can do anything from run rough to not even starting at all, when they start failing. With no previous notice either !
The smart craft takes a few forms. You can and might have the gauges they do. Gives digital data on lots of things. Or you can have a chart plotter that’s compatible show a virtual dash and no end of deadly accurate data from the ecu on fuel consumption, all engine data and alarms as well as a ridiculous amount of other data that analogue gauges just don’t. Or the cheapest option of all is the excellent vessel view mobile device that transmits all the above data and more to your phone or tablet. Amazing thing for about £200. All of the above are compatible with and simply plug into your engine. The chart plotter option requires a quite expensive adapter though. Here are a couple of pictures from my vessel view mobile on the v8 mpi and the gauges I have for the outboard boat. One picture of the expensive but excellent VesselView touchscreen unit too.

 

[billskip]

Dont forget to put the antifreeze..if it was me I'd take this opportunity to drain down flush and re charge the system with new additive.

 

[Meps1983]

I like the look of this system Qbhoy. Mine has the standard dials on but I will certainly look into this setup. Digital readings alway seem more reliable to me so can only improve things. She does have a garmin chart plotter but i dont recall seeing amything like this on there.
New hose has been ordered for the calorifier so will cracknon with that in the week.