TR4 Heater Refurb

[Paul JB]

My 1964 TR4 has had the heater matrix bypassed by a previous owner and whilst the dash is off I thought I'd investigate. I can't think why it would have been bypassed unless it leaked! I've removed the heater and disassembled it.

 

The heater matrix appears to be in reasonable condition but wondered what the best way to check for leaks would be. I don't really want to pressurise it without knowing its limits (I don't want to blow any joints etc). Any suggestions?

 

I've also put 12V across the motor and nothing happens, so I guess I need a new one of those. However, I'm not sure about the best way to remove the plastic fan from the motor. It's held on by a spring clip that is obviously designed to slide down the shaft, but not up. I've not seen any replacement fans, so don't want to be too heavy handed with it.

 

Also, there's a lot of remnants of foam seals. I've not found a supplier for these seals or the large circular seal at the top (where it mates with the bulkhead). I wondered about using draught excluder - is that a sensible?

 

I've not found much on the forums about refurbishing the heater, but I did stumble across this article: http://www.74tr6.com/heater.htm It's a good write up, but is TR6 specific (although it looks very similar). He refers to a refitting kit from The Roadster Factory, but again it's TR6. Does anyone know of a similar kit for the TR4 (preferably available from a UK supplier)? There's also a photo of the clip holding the fan on in his article.

 

Any suggestions much appreciated.

 

Thanks.

[littlejim]

You could fill the heater with water and look for leaks, but a plastic tube on one outlet, cork or finger in the other, hold it under water in a tub and blow. No bubbles no leak?

Dpending on your radiator cap psi it should be able to take 4-7 psi without busting so you could put a bit of pressure on it.

[stuart]

Use a cycle pump to put a bit of pressure into it and dunk in a bucket you will soon see if there are any bubbles,You will have to wait for a bit to get rid of any air trapped around the matrix first but dont put more than 4lbs in a TR4 unit. Your local hardware store may sell foam of varying sizes just make sure its a fire retardant type and use whats left of the original for pattern. Once you get it to bits its fairly obvious where the foam goes.

Stuart.

Edited December 8, 2010 by stuart

[ianc]

Revington TR can supply a much more powerful heater with 3 speed settings - Part RTR1396-1K for upgrade (fits inside existing casing), or suffix -2K for complete assembly.

Described by Neil as a toaster rather than a dog breathing on your knees!

Ian Cornish

[bob-menhennett]

Paul

As well as fire retardant, double check that the foam is of the closed cell variety.Ordinary foam will soak up water like a sponge.

I obtained the bevelled sponge ( at the top of the heater ) from Clayton Heaters when I did mine.

If the motor is US then a secondhand heater might be the solution, if all your money has been spent on Christmas shoping.The electric

motor rarely wears out.

You can remove the clip on the end of the shaft but very carefully.The thinest screwdriver blade you can find and work up each

fin ,a little at a time.A drop of thin oil, WD will help.

 

Bob

[Smokey]

I just replaced the core, motor and controls with a kit from Clayton. Squirrel cage fan and solid state controls. It required a bit of fiddling, but it sure works well.

[Smokey]

Victoria British in the US can supply a new core and motor for the original TR4 heater, so that's another option.

[adriantr4]

hi

 

There is/was a substitute fan motor from Moss, I think its an MG part. It is/was fantastically expensive, but I paid up & have never regretted it. The matrix is probably up to the job as it stands. My father brazed up a small leak in mine & after my refurb efforts its worked fine for years now.

 

I also put a smallish ball of foam in the passenger side demist pipe to persuade most of the blown air onto the drivers window area.

Edited December 9, 2010 by adriantr4

[MikeF]

My 1964 TR4 has had the heater matrix bypassed by a previous owner and whilst the dash is off I thought I'd investigate. I can't think why it would have been bypassed unless it leaked! I've removed the heater and disassembled it.

 

The heater matrix appears to be in reasonable condition but wondered what the best way to check for leaks would be. I don't really want to pressurise it without knowing its limits (I don't want to blow any joints etc). Any suggestions?

 

I've also put 12V across the motor and nothing happens, so I guess I need a new one of those. However, I'm not sure about the best way to remove the plastic fan from the motor. It's held on by a spring clip that is obviously designed to slide down the shaft, but not up. I've not seen any replacement fans, so don't want to be too heavy handed with it.

 

Also, there's a lot of remnants of foam seals. I've not found a supplier for these seals or the large circular seal at the top (where it mates with the bulkhead). I wondered about using draught excluder - is that a sensible?

 

I've not found much on the forums about refurbishing the heater, but I did stumble across this article: http://www.74tr6.com/heater.htm It's a good write up, but is TR6 specific (although it looks very similar). He refers to a refitting kit from The Roadster Factory, but again it's TR6. Does anyone know of a similar kit for the TR4 (preferably available from a UK supplier)? There's also a photo of the clip holding the fan on in his article.

 

Any suggestions much appreciated.

 

Thanks.

 

 

HI I am in the process of doing mine and happen to have a heater from the later car to do a two into one job.

The 6 heater is pretty well identical to that in the 4, the steps in the link you gave would be the same for earlier type. The later type has two additional pipe outlets let into the main box, which is otherwise identical. The two-speed motor with resistor is slightly larger than the one speed; the fan is the same. I would guess the 2-speed fan motor for the 5/6 is actually just the 2-speed option on the 4/4A.

When I tested my matrixes I just taped a pushbike pump thing into one inlet pipe and blocked the outlet pipe, then pumped it up after a dunk in soapy water, if there had been a leak it would have shown as foaming at the leak site.

I also flushed it through with some Killrock and detergent. (Saved going into town to get some radflush). And rinsed it with mains water using a hosepipe to inlet pipe. Quite a lot of Ratners came out.

 

Mike

Edited December 10, 2010 by MikeF

[MikeF]

Well I just put mine back together, based on that, FWIW here are my thoughts:

Forget about the foam used between the heater box parts, too fussy to assemble and as its only function seems to be as a sort of gasket I just lightly greased the flanges and used a silicone sealant. For the plate that the fan is assembled to I used thin rubber strips for a little damping.The heater matrix is buffered top and bottom with foam, I used draught excluder pieces (this is closed cell foam.) it compresses nicely. The matrix also has some foam inserts to either side to ensure airflow is through rather than round itself. I found it easier to put this in place after assembling the box/matrix (but before sealing with the fan plate). The foam can be compressed before sliding into place so goes in without damaging the fins.

I also understand now why the demist is so useless, the directional flap arrangement is a real triumph of optimism over reality. Who ever designed that did it in his tea break whilst thinking of some thing else. I am seriously thinking of some modification, as I am having real difficulty with putting it back as is.

Mike