10 replies to this topic

[jamiestevenbell]

hi i know this sounds abit random but does any one know what the internal and external bore of the heater pipe is? as i have forgot to measure mine and i wanted to buy some hose for it tonight lol cheers

[charliedurrant]

This was answered last week - the search should show you the anwser.....

Charlie

[jamiestevenbell]

cheers

[jamiestevenbell]

so it 5/8" but i have been on artel motorsports website and they only have 16mm or 13mm hose will 16 be ok or will both be useless

[charliedurrant]

5/8 * 25.4 = 15.875mm ~ 16.mm
1/2 * 25.4 = 12.7mm

The clamp will make up the difference.

Charlie

[AVV IT]

It depends on the age of the car. Early models were fitted with 1/2" heater hose but this was replaced with 5/8" hose from 1985. 1/2" hose with with flared 5/8" ends was then used by Rover on later models from 1988 onwards. 13mm hose can be used as as a direct replacement for 1/2" hose and can also be fitted to 5/8" fittings too, but does require some lube and a little persuasion. (13mm is also the standard size used for silicon heater hose that many classic mini owners upgrade to).

[charliedurrant]

It depends on the age of the car. Early models were fitted with 1/2" heater hose but this was replaced with 5/8" hose from 1985. 1/2" hose with with flared 5/8" ends was then used by Rover on later models from 1988 onwards. 13mm hose can be used as as a direct replacement for 1/2" hose and can also be fitted to 5/8" fittings too, but does require some lube and a little persuasion. (13mm is also the standard size used for silicon heater hose that many classic mini owners upgrade to).

I've always found that over stretching hose causes it to fail earlier, but are you saying (and this is an academic point) that the Rover > 1985 has essentially 1/2 inch but with 5/8 flares at the end, thus instead of buying special pipe you should use 1/2 as it has to go though 1/2 inch holes during it's passage (no pun inteded for the second time today)?

Jamie,

A local motor spares shop should hold pipe to suit they are not uncommon, if you have a little extra cash silicon is much better.

Charlie

[jamiestevenbell]

are the 1275 gt hoses the same as any other 1275? im changing the take off any way

[jamiestevenbell]

also does anyone know what size hose i need for the vacume on my megajolt?

[AVV IT]

I've always found that over stretching hose causes it to fail earlier, but are you saying (and this is an academic point) that the Rover > 1985 has essentially 1/2 inch but with 5/8 flares at the end, thus instead of buying special pipe you should use 1/2 as it has to go though 1/2 inch holes during it's passage (no pun inteded for the second time today)?

The problem you describe with stretching the hoses does sound logical, although I can't say I've ever experienced it myself. My understanding is that Rover introduced 1/2" hoses with flared 5/8" ends from 1998 onwards. Where as between 1985 and 1988 they were a standard 5/8" bore throughout. I have no idea why they introduced these flared hoses, or to what purpose they served, but to the best of my knowledge they were discontinued and are no longer available. I would think that it is probably best to replace them with 5/8" hose, as this should serve to increase the total coolant level in the system and therefore aid cooling to some extent. That said I've actually replaced them with 13mm silicon hoses on my car, as they are supposed to be more robust.

Edited by AVV IT, 22 November 2011 - 10:24 PM.

[charliedurrant]

My understanding is that Rover introduced 1/2" hoses with flared 5/8" ends from 1998 onwards.

Nothing to do with this post but I wonder why? It's a little like the door water drain hoses on My Mk II, they are flared at one end? It's almost as they guy who designed the top connection didn't talk to the chap who created the hole at the bottom of the door, but the man who designed the pipe sorted it out by flaring one end.....