Heater unit

[Spencer Parks <jkc@esper.com>]

Winter approaches and I thought it would be nice to have just a bit of heat
in the car.  The DPO has by-passed the heater coil entirely which leads me
to believe that it leaks.  I tried removing the cover per Haynes...no go.
Decided just to take the whole unit out.  Still no go.  I've removed all
the screws, bolts, clips I can find and the thing won't budge.  Is there
something else holding it in not indicated in the manual?  TIA.

Peace....
Spencer
Ten Mile, TN
1980 MGB (definately a "cool" car)