don't know if it makes it any better but on lhd they are a pain in the butt in to change. probably the same on a rhd as far as time goes. i'd say 10hrs if you do it quick 14-16 if you've never done one before imo

 

Most interior components (including the heater) on RHD models are a "mirror image" of the LHD models. Exceptions include the parking brake (mounted between beside shift lever seats on RHD). I sincerely hope that I don't have to resort to taking everything apart to change the core, but as time goes on it's looking increasingly likely.

 

Mine is almost identical...did you try the garden hose back into the radiator test? That will tell you if your core has an internal leak...can save you a few hundred bob, quid, pence or whatever you call it. Mine blew out enough heat to burn my hand so I know the core is working. I'm thinking that something is blocking the water from being drawn back into the pump.

 

Damn - that's the one thing I forgot to try. Thanks for reminding me.
Will go out & try that one tomorrow.
Will have to wait until this storm is over - boy have we got serious wind & rain today! Have just been out to get my mail out of the box & wind nearly blew me over.
Will let you know what I find - am kinda hoping it's the water pump as (apart from the expense) it'll be a lot easier to change that the heater core.

 

Hi again - finally got the problem sorted!
After a bit more testing I decided it WAS a partially blocked heater core. Although I had flow through it I could not help thinking it should flow better. Quite how it happended to get blocked so suddenly will always be a mystery - maybe some sludge let go from elsewhere in the system & lodged in the heater? Who knows?

Anyway, I decided to fill the heater up with acetic acid (white vinegar) I disconnected both heater hoses from the engine, tied them up as high as possible & filled up with 50/50 hot water & the vinegar. Left it for 24 hours. & then rinsed it thoroughly in both directions with a hose - I must have put 100 gallons of water through that thing! The crap that came out was unbelievable! I decided that using anything alkaline might attack the aluminum core so figured something acidic would be safer - although it was always at the back of my mind that I might cause a leak. Decided it was a risk worth taking.

Flushed the rest of the system & refilled with 50% Comma ethylene glycol 5 year antifreeze (not Dexcool - I hate the stuff), burped the system & heater is now hotter than it's ever been - even at idle it's plenty hot enough. Will keep an eye on the coolant level over the next few days & pray that I don't start smelling antifreeze in the cab. At least there's no mistaking the smell of that stuff.

I am one very pleased guy today - fingers crossed things stay that way!

 

glad to hear you got it fixed!!! hope you get no leaks, keep us informed

 

Thanks - when I finished my nightshift this morning at 6am we had a really hard frost so I was really glad of a decent heater again. Just been out & checked coolant level again - everything OK so far.
Will let you know if I have any problems.