Jump to content

1966 Herald Smith's heater matrix leak


Recommended Posts

My 1966 Herald Smith's heater matrix has sprung a leak and drained down onto the carpet and floor making a mess.  I took the heater apart, flushed it out expelling lots of brown rusty water, (not green coolant in the rest of the engine).  The heater or demister had not been effective in the car, presumably because it was plugged with rusty debris.

The usual Herald parts suppliers do not list the heater matrix as available.  Other sources like Demisterman.co.uk, and motoradsonline.co.uk list replacement parts.  Have club members had good experiences with these suppliers?  There are ancillary bits required as well for replacement.  What is the gasket between the heater valve and matrix?

Link to comment
Share on other sites

Easy bit first - the gasket is only an o-ring, still available (and hopefully fit for purpose)

There are a few companies making matrix / matrixes / matracies whatever the plural is, they look good enough - I bought one for the TR7 (although purchased through Robsport) and it was a straight fit. I suppose you can only try one and see how it fits, as none of the suppliers are selling any.

Link to comment
Share on other sites

and dont forget to ask a local radiator repair centre if they can effect a repair , can be very cheap

the pipe  gasket/ grommet/olive thing can be made from a short bit of heater hose maybe bevel the edges a little but this has got a good few out of trouble 

when removing the valve and finding they need to replace the seal 

Pete

Link to comment
Share on other sites

thanks, Pete, Chris, and Colin.

I traded msgs with Demisterman.co.uk.  When I showed them my matrix sketch and dimensions, they replied that one of the matrix dimensions on their website is incorrect, and that the center distance of the tubes is a little more narrow than stock. Otherwise it would fit, and "others haven't complained", as we are often told.

I chose to have a local radiator shop repair my old original heater matrix.  They took off the plain end cap, rodded the tubes, flushed well resoldered the end cap, straightened the fins and reformed a distorted tube bead.  I did a little pressure check in the sink with a ball pump.  It seems like the leak is fixed.  

I am still unsure about getting a reliable seal between the valve, plain pipe and bracket.  The existing seal appears to have been made by a triangular cross section rubber "O" ring and a paper dished washer.  Do you suppose an ordinary "O" ring was distorted under the clamping force to form the triangular cross section?  I am thinking that a rather softer durometer will allow the required distortion to for the seal.  McMaster-Carr shows soft silicone high temp "O" rings, and water, steam and ethylene glycol resistant "O" rings.  I need to make a wise choice of dimensions.  Does anyone have a record of their successful choice here?

  thanks.

IMG_2938.JPG

IMG_2947.JPG

IMG_2951.JPG

Link to comment
Share on other sites

yes the concave shape in both the valve and bracket are sufficient to squeeze the thick O ring now offered as a replacement seal onto the pipe.

Think the paper washers may have been added by a PO to increase the clamping. Only other observation is that the bracket in your photo doesnt look very well centred on the heater pipe at the moment but hopefully that will correct itself as the valve fixing is tightened up...

Link to comment
Share on other sites

I reused the manky old seal, but a good gob of silicone both sides. Then did it up, but not tight. Left a day, nipped it up. No leaks. I reckon the same idea with 20 turns of ptfe tape would achieve the same thing. Or indeed a nice fat O ring.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...