P38A Heater matrix o-ring replacement guide

Just thought I’d repost this as I did it many moons ago (before YouTube, so maybe it’s been covered on there by now), and my pdf doc is still lurking around in my Dropbox. May be useful to some, given how long the P38’s last. Back on LZ hoping to get a D3 at some point soon. Best wishes to all, stay safe.

https://www.dropbox.com/s/wfbnzyrmz...ater Matrix O-ring Replacement Guide.pdf?dl=0

Good write up and pics mate nightmare job done mine 2018 but got all dash out now so going to replace with Audi matrix no o rings

pete12345 said:

Good write up and pics mate nightmare job done mine 2018 but got all dash out now so going to replace with Audi matrix no o rings

Click to expand...

Smart move, hope it goes ok, O ring design was always dodgy.

Just don’t want the aggro of doing them again my luck get all the dashboard back in then they would leak

Audi core all the way. Nissens 70230 is the right core.

Thanks for this man...... mine's not giving trouble- yet- but it's going to someday, and now I don't have a mechanic I'd trust to do the job anymore, it'll have to be DIY-ed.

There's this sort of dreaded inevitability about it all but this guide is going to help!

Marshall8hp said:

Audi core all the way. Nissens 70230 is the right core.

Click to expand...

I didn’t know alternative core replacement was a thing, but I’ve been away a while (from P38, not prison). Presume the pipe connection is much better?

Stufer said:

I didn’t know alternative core replacement was a thing, but I’ve been away a while (from P38, not prison). Presume the pipe connection is much better?

Click to expand...

The audi core is a little bit thicker so need a small amount of the inside of the heater box cut out and a strap to hold it in and then rubber hose from matrix through into the engine bay so no more orings and no solid pipes that get knocked upseting the orings.
on the kit i got there are two short brass pipes that then join the the new to the old hoses.

Here is the kit i have ready to fit

Mine never leaked after the new o rings and only took a lazy day to do, but I’d rather do this core change for a long term keeper which wasn’t a daily driver. Thanks.

"Dash Out" version is much better idea. No horrible cutting, etc. http://paulp38a.com/range-rover-p38/dash-removal/

pwood999 said:

"Dash Out" version is much better idea. No horrible cutting, etc. http://paulp38a.com/range-rover-p38/dash-removal/

Click to expand...

Indeed, if not a daily driver, I wouldn’t want to do that in a rush. Great guide tho.

There’s still cutting even with dash out I think to make new one fit in I read somewhere but lot easier I hope

Those two brass fittings Brian what size are they and what they called I didn’t get them supplied cheers

pete12345 said:

There’s still cutting even with dash out I think to make new one fit in I read somewhere but lot easier I hope

Click to expand...

The only cut is in the heater box side to allow the Audi core to fit. I was talking about the dash frame & plastics.

pete12345 said:

Those two brass fittings Brian what size are they and what they called I didn’t get them supplied cheers

Click to expand...

They are thick wall brass 18mm od 2mm wall 45mm long with two groves each end
if you stuck you could probably use two 15mm yorkshire soldered couplings with a short piece of pipe so the two fittings almost touch each other, make up two off those and the rubber hoses wil clamp in between the ridges an wont pull off becouse of the bead.

@pete12345 just found these ont the bay they say they will do what ever size you want or you may be able to to use the 19mm ones with a bit off lube and a push and ther a good price
https://www.ebay.co.uk/itm/Brass-pi...668035&hash=item2edac493e7:g:6GUAAMXQHxVRhiAw

Cheers Brian will have a look

pete12345 said:

Good write up and pics mate nightmare job done mine 2018 but got all dash out now so going to replace with Audi matrix no o rings

Click to expand...

@MrGorsky put an Audi core in his a year or two back.

I've got an Audi core on order, seems the best way to go. Well in my eyes it is anyway