Draining radiator BX TXD

[jhunt]

I am about to drain the radiator for the first time to put antifreeze in and wonder if someone could tell me which nuts or hose to undo please?

Thanks

John

[RobC]

The thick bottom hose on the radiator is the best bet. Not sure what side it's on on diesel models but assume it is on the left as you look at the car, i.e. on the same side as the hydraulic tank. Be sure to have the heater tap on fully hot, to have the radiator cap off, and to flush the system thoroughly afterwards until clear water comes out.

After refilling make sure it's bled properly.

Good luck.

[rutter123]

Absolutely that above much neglected flushing of system has sent many bx for scrap, always flush my d and td every change.

[Defender110]

There's a plastic drain plug at the bottom right hand side, unscrew it 90 degrees and pull it out (it won't pull all the way out without depressing the locking tabs) once you have undone it then remove the radiator cap to prevent vacuum in the system.

[jhunt]

Many thanks.

I will do that.
I assume that I would flush with a water hose in the radiator. Not sure where I find the bleed nuts and would appreciate any advice on those if you can.

Thanks again.
John

The thick bottom hose on the radiator is the best bet. Not sure what side it's on on diesel models but assume it is on the left as you look at the car, i.e. on the same side as the hydraulic tank. Be sure to have the heater tap on fully hot, to have the radiator cap off, and to flush the system thoroughly afterwards until clear water comes out.

After refilling make sure it's bled properly.

Good luck.

[themildbunch]

if it's a N/A diesel there's a drain bolt / plug on the rear of the block about half way up... I doubt you'll get all the old coolant out without undoing this...

[Tinkley]

Not sure about the bleed nuts on the diesel but on the 1.6 petrol it is up near the distributor which equates to high up on gearbox side of engine when you don't have one! (dizzy that is). Just find the highest point in the system and there should be a bleed screw, though mostly just running through and topping the rad for a few days does the trick.

It is pretty easy to take the radiator out to flush it btw so consider that. Hopefully what you drain is clear or at worst slightly opaque with no signs of rust but signs of antifreeze colour.

Remember to use a 50/50 antifreeze and DISTILLED water not tap water when you refill the system and do not mix the different colour antifreeze mixtures, blue, green and pink. If you use tap water there is active oxygen in it that allows for increased corrosion inside the system which then potentially blocks the radiator. It also risks popping any core plugs out, furring the system etc etc. It is essential on aluminium engines but worth it on cast iron blocks and heads as it still keeps down corrosion. Check your hoses are still in good condition whilst at it, the rubber parts are getting old on some of these cars and more prone to failure.

[Defender110]

If you look very carefully at the bottom right I have circled the bleed screw in red, there is a similar drain screw below this at the bottom of the radiator.

[Defender110]

Sorry about the size my IT skills are minimal although slowly improving.

[jhunt]

Thanks. It great to be in touch with experts!

John

Not sure about the bleed nuts on the diesel but on the 1.6 petrol it is up near the distributor which equates to high up on gearbox side of engine when you don't have one! (dizzy that is). Just find the highest point in the system and there should be a bleed screw, though mostly just running through and topping the rad for a few days does the trick.

It is pretty easy to take the radiator out to flush it btw so consider that. Hopefully what you drain is clear or at worst slightly opaque with no signs of rust but signs of antifreeze colour.

Remember to use a 50/50 antifreeze and DISTILLED water not tap water when you refill the system and do not mix the different colour antifreeze mixtures, blue, green and pink. If you use tap water there is active oxygen in it that allows for increased corrosion inside the system which then potentially blocks the radiator. It also risks popping any core plugs out, furring the system etc etc. It is essential on aluminium engines but worth it on cast iron blocks and heads as it still keeps down corrosion. Check your hoses are still in good condition whilst at it, the rubber parts are getting old on some of these cars and more prone to failure.

[Phil Peters]

if it's a N/A diesel there's a drain bolt / plug on the rear of the block about half way up... I doubt you'll get all the old coolant out without undoing this...

I second this advice. Having chatted with Dollywobbler at the NEC back in November I decided to flush my cooling system to get rid of the red coolant that had been added by a Citroen independent when the cam belt was changed .

I found that without undoing the drain bolt on the back of the engine a load of old coolant was left in the system.

In the end I had to fill/drain/flush the system 3 times to get the entire system running clear before finally filling up with blue coolant + distilled water and then bleeding the system. It was worth the effort though as the system has been spot on ever since.

[Defender110]

Having chatted with Dollywobbler at the NEC back in November I decided to flush my cooling system to get rid of the red coolant that had been added by a Citroen independent when the cam belt was changed .

Why did you want to get rid of the red antifreeze, it is still a MEG (Mono Ethylene Glycol) based engine coolant suitable for all petrol and diesel engines but is a better/long life antifreeze.
Long Life Antifreeze

The orange/red is a product currently used by many vehicle manufacturers. Orange or Red antifreeze known as long life or extended life antifreeze increases the useful life of engine coolant. Long life antifreeze is also ethylene glycol based.
The difference between the two colours is that Orange / Red antifreeze contains a different type of corrosion inhibitor that has a much longer life than silicates, phosphates and borates. Orange / Red antifreeze contains organic acids that protect engine parts from corrosion.

[Phil Peters]

I think the problem in my case was that the system hadn't been completely drained of the old coolant so when the red stuff went in it mixed with the remaining blue coolant and created a red/orange scum. "Precipitates" I think is the correct term. This solidified on the underside of the radiator cap and dried to a soil-like consistency. Very nasty.

Others may have had better experiences using the red coolant but I decided to go back to blue coolant as this was presumably what the car would have originally had back in 1992. I don't mind changing it every two years as it's a good prompt to flush the system and generally check the condition of hoses etc.

[citsncycles]

I have no problems with the red stuff in Timex, but then all the old coolant had been pushed out by the cracked cylinder head!

There's some new stuff out that apparently works with all types of coolant, but I've not tried it yet.