Heater Tap Replacement - How To

Frequently asked technical questions and common modifications/improvements
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DLM
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Re: Heater Tap Replacement - How To

Post by DLM »

=D>
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Re: Heater Tap Replacement - How To

Post by paulwitchard »

I've just had a timely look at this - and found a couple of things I hadn't done putting a replacement heater radiator in. A couple of questions though -generally speaking is it more likely for the 2 seals between the tap and heater to leak, or the operating 'gate'? The gate goes up and down so I assumed it wasn't stuck.
Is there any way to test for leaks before the engine goes back in - by connecting a a garden hose and operating the on / off valve for example.
Engine's out, and car is LHD so access is a bit better.
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Re: Heater Tap Replacement - How To

Post by RobC »

garden hose would work to an extent, but bear in mind that the cooling system operates at 1 bar/ 15PSI, so you'd need to be able to get the pressure up to that amount to be sure of no leaks
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Re: Heater Tap Replacement - How To

Post by Vanny »

As Rob says, you'll need a bit of pressure to go with the hose. I'd run the hose in the top port, then slowly put a bung on the bottom port. Use an old tyre valve in the hose and you should be able to add some pressure. Dont over do it though.

if you've put a replacement rad in, then the connection between the tap and the rad will likely be leaking. Probably didn't flip the seals and or put sufficient RTV at the bottom of the tap side groove.

They do leak through the gate shaft. there is an o-ring in the tap where the metal bar passes through. You can replace the o-ring, but oh is it fiddly.
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Re: Heater Tap Replacement - How To

Post by paulwitchard »

Some further information - apparently the seals are called 'Nu-lip seals' and are an X section (according to my brother who has recently retired after a long career in the bearing and seals trade) and I've managed to acquire some from a firm in Loughborough. They will be on their way to Normandy by the end of the month after I pick them up on a visit to the UK.
I'll report back on how they fit when I've had a further fiddle with it.
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Re: Heater Tap Replacement - How To

Post by Jaba »

paulwitchard wrote: Fri Jan 24, 2025 3:21 pm Some further information - apparently the seals are called 'Nu-lip seals' and are an X section (according to my brother who has recently retired after a long career in the bearing and seals trade) and I've managed to acquire some from a firm in Loughborough. They will be on their way to Normandy by the end of the month after I pick them up on a visit to the UK.
I'll report back on how they fit when I've had a further fiddle with it.
A good bit of detective work there. Just what we need when we have to make do and mend to keep our BXs fully functional. Don't forget to let us have full details when it is all done.
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Re: Heater Tap Replacement - How To

Post by Vanny »

The original seals are simple square-cut seals, they take a set on one side because of the plastic moulding line. So, while it looks like the seals are grooved when they come out, they don't go in with a groove. I understood that X-ring seals (NuLip) are for sealing linear motion shafts, so stop the seal from turning out when moved in one direction and then the other. X-ring are certainly not the orignal seal type, but i'm intrigued to see how you get on with them.