Coolant hose ID

[cobaltcodd]

To save me taking it off and measuring it, does anyone know the ID of the lower radiator coolant hose for a crossflow?  It's because I'm converting to a pressurised system and need to put a t-piece in there for a 5/8" take-off

thanks

[elie boone]

For a closed system you don't need a T in the lower radiator hose but one in the 16mm hose that exits the water pump.

[cobaltcodd]

That goes to the heater - so just go into that?  It would be easier and neater and less hose run, but Caterham originally supplied a t-piece (a "submarine") for the lower rad hose and also one of the most knowledgeable xflow people ever also agrees with doing it that way.  Are there pros and cons for both ways?

[elie boone]

If you look at your water pump you will see that both are before the impeller so there are no pro's or con's for both way's

[grumpy the 7th]

Bit OT but check your hoses regularly.  Completely OT.

Have a look at my boiler flow link pipe, this went with an almighty whoosh a couple of months ago on a Saturday night and fixed by Sunday lunch. The hose must have been perished a long time and finally gave up. The new hose (clicked & collected from Halford's) 10 bar & 120 degs C more than covered the spec. 

I'd have never got a plumber so quick (or so cheap) and I have 60cm of spare 19mm heater hose

                

Boiler got it's annual last month and they never mentioned (noticed) the new hose dated May this year and I'd hovered the moths out and cleaned the boiler insides.

[jonsymons]

I'm looking to do the same conversion to my (recently acquired) crossflow over the winter. Would you mind posting a few photos of the finished job and any hints?  I've got a rough handle on whats involved from the various posts on the forum but keep hesitating to start when I look at the rusty bolts holding the thermostat housing...

Thanks

[cobaltcodd]

Some photos as requested.  You need a new thermostat housing and gasket - the type with a vertical take-off.  The expansion tank is from a Rover 214 - very hard to buy new - After a month of looking I joined the Rover 214 Facebook group and asked - and some bloke had about 10 (he breaks and deals in 214 spares).  It has a long front mounting bracket that has to be cut off.  You need a length of 8mm hose to connect the outlet on the top of this to the outlet on the new thermostat housing.  I had to extend the wires connecting the thermostat fan switch on the housing as on the old one it was on the side so they would reach, now its on top so they wouldn't.  Also needed are a couple of L-brackets to mount the expansion tank onto the heater.  I still have to connect the lower outlet on the new expansion tank to the system - either into the lower rad hose using a 36mm x 36mm x 15mm T-piece OR into the return of the heater hose using a 3 x 15mm T-piece.  I have no heater control on mine and that simplifies things.  With one you would have to go into the lower rad hose because if the heater control was closed then water would expand into the expansion tank, but the water pump couldn't empty it (I think)

 

 

[jonsymons]

Thank you! 

[elie boone]

You can also use a Clio expansion bottle https://www.ebay.co.uk/itm/Renault-Clio-Mk2-1-5-dCi-2-0-16v-Sport-Radiator-Expansion-Tank-Bottle-Cap/163231324908?fits=Car+Make%3ARenault%7CModel%3AClio&

[cobaltcodd]

I couldn't see a place to fit the clio one as I have a heater so there isn't enough space between that and the bonnet.  Without a heater it would be perfect.  It could have fitted elsewhere around the engine bay (eg, above the steering rack area), but I thought it had to be higher than the engine?