Technical MATRIX probs?

[Hotboy]

Has anyone had an overheating prob thanks to a Matrix blockage??

How can you flush this out? My 1987 70sx has 2 hoses, in and out, that vanish into the body and underdash matrix. Can I reverse flush with a hose pipe?

 

[F R O S T Y]

I think i may have this same problem, i was told by a friend that my blown radiator, thermostat and header tank may have all been destroyed by pressure built up due to a blockage in the heater matrix. When you put the heaters on only cold air blows out, never hot air on my mark 2 Uno Turbo. I have also noticed that sometimes coolant is leaking from behind the injector plenum from a "Y" shaped connecting piece and turns into steam when it sprays over hot engine parts. The Jolie Clips are as tight as can be and the hoses seem fine and dont have any splits whatsoever. It doesnt even spew water out, more just bubbles. I'm puzzled. Does anybody else have any suggestions as to what might be the cause??
F R O $ T Y