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MG MGB Technical - heater core

I seem to have a leaky heater core. The winshield seems to fog up all the time and the floor is getting wet on the pasengers side. Has anybody taken out the core? I have taken out the screws but there seems to be something inside the car holding it in place. Any ideas?
GK George

Hi GK,

Its probably the heater control cable. On my RHD vehicle the cable can be accessed by removing the foot heat control panel and loosening the screws. This panel is located under the dash in the drivers side footwell.

I would check the hoses as well.

Herb
H J Adler

Check it out

http://chicagolandmgclub.com/photos/b_heater/

and

http://www.mgb-stuff.org.uk/
click 'spanner' and then 'Heaters'

Putting it back in can be a bit of a bitch but a little Vaseline works wonders
MGBV81

On U.S. cars the hear cable is accessed through the heater air
exhaust port that is on the starboard side leg well.

It takes some skill at being a contortionist as you have to
stuff yourself (+ tools + worklight) in the leg well to get at
the cable hold-down mechanism.

Once the cable is free, it can take a good amount of pulling,
and yanking (and colorful vocabulary) in order to wrest the
heater box out.

You'll have fun getting it all back in, too!
Daniel Wong

There may (should) also be a fourth screw on the end, directly beneath the blower motor.
Roger T

Daniel, you think its tricky on a US (left hand drive) car. You should try it on a UK (right hand drive) car when the steering wheel and the pedals are also in the same space.
I wonder if GK's steaming-up problem isn't caused by blockage in the heater air box drain (Tom's knob). In case you don't know, the rain that enters the air box through the vent in front of the windshield is supposed to drain out via a tube that exits under the car on the RH side up beside the gearbox. The tube has a bulb (Tom's knob) on the end supposedly to prevent fumes entering the cabin. This can get blocked with general crap, in which case the water backs up into the air box and overflows eventually into the footwells.
Mike Howlett

Definitely one to eliminate first before getting the heater out! Although it isn't going to be that if you don't drive and park in the rain. Peer in the intake at the base of the screen and you should be able to see the bottom of the airbox, not water. You can rod the vent out from above (rather than from underneath and getting a face-full), have a look at http://www.mgb-stuff.org.uk/wn_heaterframe.htm and click on 'Air Box'.
P Hunt

This thread was discussed between 02/12/2009 and 05/12/2009

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