Thread: Leaking heater box

this is a tiny bit OT but I looking at many 110 / Defender heaters I found them to be the highest point of the cooling system, so likely to have air locks in them. I fitted an air release valve to mine - I run a heater from a td5 in a 4BD1-T and it gets so hot that in Canberra Winter I can have the windows a bit open at night in sub zero temps and still be completely toasty warm.

In fact I was worried about melting the vents and stuff.

Just food for thought if you are considering why your heater is crap!

Hi, I replaced the heater matrix in my 2001 130 (with air conditioning) recently. The crimped seal between the alloy core and the plastic ends on the matrix appeared to be the cause of my leaks.

The heater box must be removed from the vehicle to replace the matrix. The top two retaining bolts on the heater box are straight forward as there are captive nuts in the firewall. However, the lower two retaining bolts/nuts are plain through bolts with the heads high up behind the aircon unit in the passengers footwell. Impossible to reach without disconnecting the aircon in my opinion.

My approach was to cut through the lower nuts with a dremel or similar - punch the bolt heads into the cabin - and install captive nuts on the firewall same as the top mounts. This is the way Land Rover should have installed in the first place - obviously aircon was an afterthought!

Worked for me. Hope this technique helps others.