NOS Heater Hose

You are probably used to seeing Ds with the white plastic, cable operated heater valve on top of the heater matrix. Things weren't always that way.......

Prior to the 1969 model year (before September 1968), the heater control valve was operated by a rotating knob on the bulkhead below the dashboard. 

Pallas Heater Control - pre 1969

In fact the knob IS the valve: the valve part is in the engine compartment and buried way down at the back of the engine where the timing chain is.

The Heater Valve is on the Engine Bulkhead

The valves get silted up, or the knob goes stiff - or both. It is just about possible to service the heater valve with the engine in, but it's not much fun. (Don't ask me how I know). 

Because the valve is on the bulkhead, the metal pipe that runs from the cylinder head, along and over the exhaust manifold,  has a downwards curve at the end - so that the rubber pipe that connects to it dips down behind the timing chain cover to the valve - rather than running horizontally across and round to a valve on the heater matrix.

While my engine is out I'm planning to overhaul the valve and change the seals. I also needed to get one of the metal pipes with the curve at the end, as mine was silted up and the curved end had completely rusted off! I found one - but it was considerably more expensive than the straight ones found on late cars.

Heater Feed Pipe - 1965 to 1968

I also wanted to replace the rubber pipes that connect to either end of the heater valve - as they are hard to get to once the engine is back in the car.  The one on my car that runs between the valve and matrix in the 'snail' blower looks to be original as it has a grey outer shroud on it. It looks to be in okay condition. However the 'S' shaped one between the metal pipe from the cylinder head and the valve had seen better days and is perished. I bought a reproduction one at Citromobile in Holland in 2016. 

More recently I got lucky and found a NOS (new old stock) one. Same price as the repro one! I couldn't resist.

Reproduction parts sometimes get a bad press for their shape, colour fit or quality, Sometimes all three! Out of curiosity I've compared my heater pipes:

• Starting from the bottom we have the new old stock part. It has a distinctive 'S' bend shape to it and an outer protective grey sleeve.
• Above that is the reproduction part I bought in Holland. It's pretty close in shape to the original. The curves seem sharper, and it hasn't got quite the right profile, though it's sufficiently close to be bent to the right shape. The end are longer - but it's easier to make something shorter that it is to grow it by a few inches - so that's not a problem. It lacks the grey outer plastic covering.
• Above that is the 'S' shaped hose that came from my car. It's clear that it's just a piece of hose of approximately the right shape that someone has put on at some point.
• The metal pipe with the curved end is at the top. The only difference from the one fitted to later cars is that small kick on the left hand end - but they are nearly double the price of the straight-ended ones.

When I get to that particular job, I will fit the NOS heater pipe. Maybe I should keep a look out for a NOS pipe for the other side?