40 replies to this topic

[megamini_jb]

Hi, putting a new rad/coolant in mini. Taken bottom hose off and it's drained most coolant but still sitting max on expansion tank. How do I get that out? Need to drain properly as changing different colour coolant.

Cheers

[robminibcy]

Take the thermostat out.

[cooperdan]

Hmmmmmm...

[CityEPete]

A big syringe is handy for putting things in or getting stuff out!

[SiZT]

These have low pressure expansion tanks (assuming it's an r50)

[megamini_jb]

Yeah all done. Just need to bleed it tomorrow.

How do I go about it....

Yep R50

Edited by megamini_jb, 02 January 2015 - 05:14 PM.

[megamini_jb]

Do bleed screws open before start putting coolant in?

I'm read loads of guides, but confused more now because they keep going between R50 and R53 so mixes it up.

Way I am going to do it is

Bleed screws open
Put coolant in proper filling cap
Start engine
Watch for bleed screws to let coolant out
Keeping eye on expansion tank and top up as go along
When happy close bleed screws

Job done?

Edited by megamini_jb, 02 January 2015 - 05:26 PM.

[megamini_jb]

Nice new rad

[mab01uk]

The key thing with the R50 MINI is to avoid air locks as much as possible so fill slowly and take your time to allow air to escape, bleed valves can be left open with engine off while filling, not much will come out and you can always shut them quickly if required. I would then start engine with them shut and then bleed as coolant circulates and warms up. Check them several times and keep topped up if level drops so no further air enters the system. The MINI can be a pain to bleed of air so take your time and check levels regularly after driving for the next few days. If the heater goes cold when on hot beware as this means the heater has an airlock and can cause serious engine overheating when the level drops. A nice hot heater is a good sign of coolant circulation so keep it on as a check for a few days when possible.

I am sure you know but do not remove the pressure cap when engine is hot !

Also remember when the filler cap is off during topping up and the engine is running the cooling system will not be pressurised by the pressure cap so can boil at a lower temperature.....therefore don't leave it running with the cap off for too long without keeping an eye on things.

 

The 3 bleed valves on R50 MINI Cooper/One:are:-
In the radiator top hose (left).
In coolant pipe at the right hand front corner of the cylinder head near thermostat housing/filler cap.
The 3rd heater hose bleed valve is beneath the battery tray.

 

Filler cap on engine thermostat housing is the correct place to fill from on R50.
The pressure/filler cap for the cooling system on the Cooper/One is not on the expansion bottle, that is only a flip-off cap.

The pressure/filler cap is at the gearbox end of the engine, between the cam cover and the air filter intake hose. It has (or should have) a yellow warning sticker about not opening when hot. It is sometimes difficult to open as it has the spring for pressuring the system, press it down and rotate anti clockwise. Fill the coolant slowly here, then top up the expansion tank to the correct level. Turn the heater control to full hot and run the engine, topping up the further coolant as it circulates and the air comes out. Open the bleed valves and let the air out until coolant flows, then close the valves. When you're happy that the system is bled, turn off the engine and put filler cap back on. Make sure the level in the expansion bottle is correct and keep an eye on the level and temperature gauge for the next few days incase more air comes out. Remember modern engines often have a low coolant capacity for quicker efficient warm up but can give less warning of any overheating problems if the level drops. Also note the temp gauges are designed not to move from 'normal' over a wide range of temperatures so again give much less warning of a problem than old style gauges when a problem does occur..

[megamini_jb]

Glad to see you Martin

Ok thanks that cleared it up a lot.

That's main thing wasn't too sure about. Never done it before you see and keep reading different things on guides

Edited by megamini_jb, 02 January 2015 - 05:54 PM.

[Chance]

Good luck...i hate bleeding the coolant system on my metro..people say it is easy but i always end up with an airlocked heater matrix which i think i have know because the heater is PANTS!!

I need to look into it actually but just havent done anything over christmas...apart from sleep, eat and drink..not good.

If prices fall to around the 1000 mark at some point i might own a MINI..

[megamini_jb]

Good luck...i hate bleeding the coolant system on my metro..people say it is easy but i always end up with an airlocked heater matrix which i think i have know because the heater is PANTS!!
I need to look into it actually but just havent done anything over christmas...apart from sleep, eat and drink..not good.
If prices fall to around the 1000 mark at some point i might own a MINI..

Yeah not looking forward to it.

Changing the rad was nice and easy, wasted most time trying to fish out my bottle top I lost in the engine bay got it in the end, then fell in again gawd knows where it landed that time

[megamini_jb]

Do I completely fill the system with the new coolant before starting engine and bleed process?

[ANON]

as full as you can get it. i always fill with as many pipes off as possible, makes it so much easier. never had a problem with anything even celica and they are renowned for being an absolute nightmare to bleed.

[mab01uk]

Also note the second bleed valve mentioned above can be difficult to see and get at.

In the picture on the MINI2 link below (post no.4) it is the smaller shiny metal hex head bolt in black pipe near themostat housing and filler neck. (8mm I think?)

 

Help me find the third coolant bleed screw plz :-

http://www.mini2.com...-screw-plz.html

Edited by mab01uk, 02 January 2015 - 08:12 PM.