Coolant hoses

[Scholar Gypsy]

A persistent leak in my coolant system (which I think I have finally tackled, by adding a Jubilee clip in a rather inaccessible place) makes me think it is time to replace my coolant hoses and clips. 

 

Can anyone recommend a good general supplier of hoses?

 

It's a Mitsubishi engine with Bowman heat exchanger, and I need three bespoke sections (2 with 90 degree bends, one with about 135), plus a couple of straight sections, plus smaller hose going to the calorifier. I have of course forgotten to measure the OD of the pipes the hoses fit onto, I will do that on my next visit to the boat ...  Should I expect to get sections exactly the right size, or buy them too big and cut down to fit?

 

Many thanks.  I am also interested in finding an easier way to disconnect the bottom hose from the skin tank, as this is needed in order to insert a pela pump and pump out the skin tank. Has anyone found an easy to undo (but not so easy that it comes apart when I don't want it to) straight connnector that I could use?

 

[Nut]

try john craddocks

[Tracy D'arth]

Lots on ebay.  Look for silicone rubber coolant hoses. There are firms that will make reducing hoses to order.

[Tony Brooks]

Taking the bottom hose off the engine end and dropping it flat into the bilge is often easier unless you have a horizontal skin tank. I can't see why that won't drain all but the last litre or two of coolant. Then raise it high and fill with fresh water through the hose,and lay it sown a few times to flush the tank. Otherwise make sure the worm drive clip has a hexagon as well as a screwdriver slot so you can use a 1/4" sq drive socket and very long extension.

[Scholar Gypsy]

11 minutes ago, Tony Brooks said:

Taking the bottom hose off the engine end and dropping it flat into the bilge is often easier unless you have a horizontal skin tank. I can't see why that won't drain all but the last litre or two of coolant. Then raise it high and fill with fresh water through the hose,and lay it sown a few times to flush the tank. Otherwise make sure the worm drive clip has a hexagon as well as a screwdriver slot so you can use a 1/4" sq drive socket and very long extension.

Thanks to all for their comments. 

 

Both pipes go into the skin tank near the top, so there's about 25 litres that I had to pump out using a Pela pump - photo in here somewhere:  https://scholargypsy.org.uk/2016/01/24/january-maintenance-trip/.  I did refill in the way you suggest, Tony. 

[Jen-in-Wellies]

18 minutes ago, Tony Brooks said:

Otherwise make sure the worm drive clip has a hexagon as well as a screwdriver slot so you can use a 1/4" sq drive socket and very long extension.

Second this advice. Also, stainless steel jubilee clips are worth the extra cost over the long term, especially for the skin tank bottom connection, if your bilge occasionally gets wet.

35 minutes ago, Tracy D'arth said:

Lots on ebay.  Look for silicone rubber coolant hoses. There are firms that will make reducing hoses to order.

These made to measure silicone hoses are good. There can be some initial "set" of the hose when the jubilee clip is first tightened, so it goes loose again. Worth checking the tightness again after a few days/weeks. Silicone seems to be more prone to this than rubber hoses. On the plus side, they don't go spongy from oil contamination. Also come in a variety of colours for engine room bling!

A good source for hoses, joiners, bends in a variety of sizes are the companies who supply to the classic and kit car enthusiasts. The same stuff, but without the marine mark up. There are also flexible hoses that will do shallow bends. Try here, or here.

 

Jen

[Tony Brooks]

That looks like a horizontal skin tank but can't see the connections clearly ---- not that seeing them would make much difference.

 

I notice that some of the clips in your first photo in the post are far too large for the hose size. That makes the bow under the worm drive bit too shallow so they may not seal where the screw strip comes in/out of the worm drive part. Similar for undersized clips screwed together to make a longer one.

 

Visually the hoses look OK as long as none are chaffing but give them all a good squeeze. If any crunch under pressure they have gone hard inside so they need changing. If the one near the oil drain pump or any others are softer than the rest then they needs changing. Yours look OK but if the part on the outside of the hose clip is splitting then keep an eye on it and change when convenient.

[Scholar Gypsy]

Thanks again - sorry for delay in replying but I have been in a car all day...  I like the idea of colour coding - red for hot and blue for cool? 

 

The hoses all feel OK but they are 25 years old now, and one of the joints has been leaking a bit too persistently (hence the extra Jubilee clip which does seem to have made a difference). There's also a little bit of vibration damage where there has been a bit of chafing, something I am a bit obsessive about. Nothing urgent here, I think, but I will have a go later this year. 

 

I may think further about a Y piece to permit easier access for draining, I am probably making this over complex though ...

[Tony Brooks]

Good thought. Depending upon the hose run and connection even a T with the blanking cap on the top leg - cap off straight into the tank with the Pella pipe.

Edited March 13, 2020 by Tony Brooks