MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - mgf coolant bleading

i'm gonna replace my coolant pipes on friday ,
in the manual is states that the expansion tank must be filled to the brim and the cap fitted after initial bleeding from the heater and rad, then run the engine until the fan comes on.
whenever i have refilled the coolant on other cars i'v always left the cap off to allow any air to escape.

can anyone tell me why its different on mgf.

cheers

mick
mick

I confess that I don't replace the cap when bleeding the coolant system - perhaps I ought to?
Rob Bell

Neither do I.

However do fill it to the brim as air will escape causing the level to drop.
S Laithwaite

Mick,
As an x automotive technician i always replace the cap on initial filling as if you do get an excessive air lock without the cap in place it will blow loads of coolant all over the place. So ,fill it up ,OPEN THE BLEED SCREW AS DIRECTED,and bleed the system, fit the cap,run the engine up untill the fan cuts in, "the rad fan not the engine bay fan " let the engine cool down , and i mean cold, refill the header tank ,bleed again ,replace the cap, run the engine up again let it cool again ,then top up to the correct level and you should have no problems.
Robert
R J Hemphill

THANKS FOR THE REPLYS GUYS

just didnt know wether to do it my tried and trusted way or go by the book.surely if the cap is on there is no way the air can escape?and why do you need to wait until the fan comes on? the water is circulating through the rad long before it comes on
mick

Hi Mick
I had the cap on when I ran my car for the first time after bleeding my system...seemed to work fine. i think there should not be much air in your system if it is properly bled.
I had a very easy time bleeding my system last week after fitting new coolant pipes.
This is what i did and all went very smoothly
1- take a look at the "Jiggle valve" as mentioned on this web site http://www.mgfcar.de/bleed/index.htm
2- make sure the heater is switched to full on
3- open all the bleed points fully
4- ask 1 person fill the coolant bottle and another person watch the radiator bleed point till no air bubbles can be seen. retighten the bleeder bolt
I used a clean oil tray to catch the excessive coolant.
5- attatch a clear tube to the heater bleeder nipple (the same as if you were blleding brakes)and open. If you dont get any flow remove the bleeder nipple and make sure it is not blocked by blowing on it with your mouth. If this is not blocked and you are not getting any flow, poke a blunt object into the bleeder nipple hole and move it about. The hole it self could be blocked but be prepeared to re-insert the heater bleeder nipple quickly. Keep your friend topping up the bottle and wait till you can see no air in the clear tube. re tighten the nipple
6- 3/4 fill the cooant bottle and repace the cap. Run the car till the fans come on and switch off the engine
7- wait a while (have a beer)
8- open the bleeder screw on the radiator return pipe (in the engine bay) and bleed. I admit i did this whilst the car was still warm but not hot and no coolant came out. My friend then opened the coolant bottle cap and out flowed the coolant with no bubbles so i quicky tightened the last bleeder screw and the job was completed.

Good luck

I read the instructions on this web site and was amazed how easy it was.
http://www.apttony.co.uk/

Sorry if i rattled on to much but i hope this info is useful to you.
P. Russell

thanx for all the info
i did my pipes today and all seems to have gone well,however i did have find the heater bleed nipple was blocked and i had to remove the nipple completely and have a little poke about,as you say ,you have to be quick getting it back in.i also had a look at the jiggle valve but it seemed to operate ok.i have just been out to top it up again(only about half a pint)but i will keep an eye on it for a few days, there doesnt appear to be any leaks and the fans coming on ok. so fingers crossed.

thanks again

by the way ,its to cold for a beer here.
j watson

Hi,

after all this well done bleed jobs, might be useful to add pixfrom the mad jiggle valve at the inlet manifold

connection stud after remove of the hose
http://www.mgfcar.de/inlet_manifold/DSC01734.jpg

The non return valve 'behind' the stud, or better said, 'at the other end of the stud'
http://www.mgfcar.de/inlet_manifold/DSC01737.jpg

Will include this pics to the beed site.

Regards
Dieter
Dieter K.

This thread was discussed between 07/04/2004 and 10/04/2004

MG MGF Technical index

This thread is from the archives. Join the live MG MGF Technical BBS now