Calorifier water hose -- should I replace?

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shoc

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The water hose from my Perkins 4236 to the calorifer is at least 20 years old and I've noticed they are quite soft at the calorifier end but still stiff at the engine side.

There doesn't seem to be anything marked on the hose apart from the year ('97) so should I replace them?

Also theres no shut off valves fitted so I could fit these while I was replacing the hoses, although I'm not sure why I'd want to shut off the circuit, apart from an issue with calorifier that required disconnecting it.

So if the advice is to replace them, a few advance questions
-I've measured the outside diam of the pipe which is 20mm, so I'm assuming I should order 1/2" engine water hose.
-what will happen when I disconnect the hose? I presume the anti-freeze header tank will just drain and I'll need to replace the contents and thats its not under pressure or anything?
-how do I measure for replacement shut off valves? I presume I fit them on the engine side, also where would I source them?
-any other tips on doing this job?







 
I had a similar problem some years ago, to the extent that a leak had developed. There was a lot of hose to replace, so I just cut off the damaged foot or so and replaced with new, and some connectors, thus creating several new potential leak points!
 
I've just had the pleasure (ha ha ha - yeah....) of replumbing and relocating my hot water tank. Poxy job! Plumbing had developed a slight water leak that kept cycling the pump every 4 hours which gradually (over 6 weeks or so) got to about every 40 minutes). Pipes had started to go horrible so ripped them out and replaced. Mine was metric plumbing so can't advise.

This time I just made sure I had isolators everywhere as the original install only had 1 isolator in the whole system and that was from the supply tank low pressure line. So when I had to take the hot water offline, I lost both hot and cold :(

I also fitted a thermostatic mixer valve as with my 2 Volvo's the water comes out like a steam cleaner after 10 hours of planing at 18 knots.
 
shoc said:
The water hose from my Perkins 4236 to the calorifer is at least 20 years old and I've noticed they are quite soft at the calorifier end but still stiff at the engine side.

There doesn't seem to be anything marked on the hose apart from the year ('97) so should I replace them?

Also theres no shut off valves fitted so I could fit these while I was replacing the hoses, although I'm not sure why I'd want to shut off the circuit, apart from an issue with calorifier that required disconnecting it.

So if the advice is to replace them, a few advance questions
-I've measured the outside diam of the pipe which is 20mm, so I'm assuming I should order 1/2" engine water hose.
-what will happen when I disconnect the hose? I presume the anti-freeze header tank will just drain and I'll need to replace the contents and thats its not under pressure or anything?
-how do I measure for replacement shut off valves? I presume I fit them on the engine side, also where would I source them?
-any other tips on doing this job?
Click to expand...

You should be able to get everything you need; hose, valves and any new fittings, from ASAP Supplies but check the ID ... that is what matters , not the OD
 
Last edited:
VicS said:
You should be able to get everything you need; hose, valves and any new fittings, from ASAP Supplies
Click to expand...
The bits and pieces were readily available from my usual engineers locally. You need to specify potable water hose for the temperature range.
 
vyv_cox said:
My calorifier hose is 16 mm bore. Seems to be fairly standard for car heater hose.
Click to expand...

Heater hose was traditionally 1/2", 5/8" or 3/4". 5/8" was probably more common, which equates to your 16mm :encouragement:

No need for "marine" hose here, car heater hose is eminently suitable.
 
So I've found a supplier for shutoff valves but they need to know the thread size.

If I unscrew the connector shown in the pic below, what could I plug the hole with?

 
shoc said:
So I've found a supplier for shutoff valves but they need to know the thread size.

If I unscrew the connector shown in the pic below, what could I plug the hole with?

Click to expand...

My shutoff valves are located in the middle of the two hose runs from engine to calorifier and back, I just got two valves and four hosetails for the correct diameter hose and threaded to match the valves all from ASAP supplies ( www.asap-supplies.com). If you did the same you might be able to clamp the old hoses shut before cutting them, and then if you fitted the valves, closed them, and then replaced the four pieces of hose one at a time then the lack of a way in to the system for air should mean that not too much of your engine coolant comes out.
 
Very glad I tackled this job, as I was taking off the old hoses, I noticed it had already split but was held tight by its position.



And the hosetail connector is quite blocked;



Next comes a good flush & descaler...
 
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