406 Heater matrix - much of a job?

This car just KNOWS when I'm about to make a serious trip.....

1998 406 estate, just clocked 100,000miles. I'm driving down to the french
alps next week, and yesterday I smelt hot coolant inside the car, and
noticed the windows steaming up. Checked the coolant and it had lost about 3
pints since a service 2 weeks ago :-(

I dumped a can of Radweld in it, and it SEEMS to be holding up. (although
dare I risk the trip with it?)How do you access the heater matrix, does the
entire dash have to come out?

thanks,
John

 

If the 406 is like the 605, the leak is probably from where the 2 pipes
enter the heater matrix. A ring of rubber at the union deteriorates with age
and the coolant escapes into the right side footwell.
Check this before removing the matrix ...

Ivar petur

 

Thanks. will check it!

 

Same applies to the 405 !

 

Oh, and your local plumbing supplier should have a tube with a rubber
lubricant, if you need it. Take care not to use something you just have
laying about - some lubricants will destroy the rubber in practically no
time at all.
I got a set with the two rubber rings at a Peugeot dealers' at
the ))reasonable(( proce of GBP 12.

Ivar Petur

 

Previously in this group someone pointed to an extremely helpful
http://rangerovers.net/repairdetails/heateroring.html
which shows in detail how the matrix connection o-rings work on a Range
Rover, and that part of the connection looks much the same as on a 405.
In a 405 they are above and to the right of the glove box, which you
have to take out if you are not to remove the whole fascia.

 

Thanks. A useful document!

However, the Radweld seems to be holding it for now. As its now clocked
100,000 miles I reckon its about time to get rid and buy a proper car!