Hi.
Hoping to change heater matrix orings on RHD.
YouTube makes it look possible.

Reading about others attempts....
One user suggesting using larger rings. Standard 22x2.5mm? Using 22x3mm instead?

One user is adding much sealant around standard rings.

Lots of cheap nitrile rings listed, but VXs ive bodged use silicone not nitrile rings (on cooling hoses). Are the LR parts nitrile or silicone?

Should I just stick to the standard rings? Am I likely to get 5+ years from standard parts?

If I do add sealant, can I use my favorite wellseal or should this be silicone? (Don't want silicone in the heater water/matrix).

Thanks again

do not use silicon anything unless its grease to help in assembly. use nitrile o rings , some recommend buying original o rings as they arnt that expensive. done properly they will last many years. do not over tighten them as you can crack the housing, just tighten and then loosen off half a turn for expansion!
PS if the screw is tight or corroded at the back of the screw you might have to drill the head of the screw and unwind the rest of the screw out the back of the retainer. you may have to buy a longer than usual drill bit to reach the screw.

Thanks madas.
I can see a few genuine orings around £12 a pair.
If these are 10 or 20 years old, wouldn't it be better to use recently made ones (providing I use good quality)?

What's the reason for rejecting silicone? Is it because of diy abominations that you've had to unpick, or is there an engineering problem (other than getting silicone in the cooling system)?

I've pulled silicone blobs from oil ways on small engines I've bought, it is saddening. And nothing is as ugly as big pile of silicone sticking out both sides of the gasket 😀.

My first thought was a little wellseal (the sticky brown trichloroethane solvent stuff). This might be a bit too sticky, almost like trying to seal it with epoxy 😀. A small amount of good quality silicone (not hylomar or bath sealent) will allow the orings to move as the assembly expands and contracts.

I'm all for fitting original gaskets with out sealent, it is what the manufacturer designed. But I'm from a jap motorcycle background. Gaskets are extremely expensive, casting gasket faces are a little rough (makes for a good seal) and it's usually very difficult to remove your expensive cover gasket in one peice (even when just fitted) unless you first coat in a thin layer of sealant (like wellseal).

Many thanks

I always use genuine LR ones and haven't had a leak yet. If you look at the way the connection is designed, the O rings aren't crushed into the joint but the clamp stops them from being bolted up tight which allows some movement which is taken up by the 'squashiness' of the O rings, so you don't want them glueing in place as they are more likely to leak than less.

Thanks Gilbertd. Agreed, we want the orings to move with expansion/contraction. A solid (expoy like) seal will fail sooner than nothing.

If you've had plenty of success with LR seals, I will use those.

I'm not going to try, but it would be interesting to see softer silicone orings inplace of the nitrile ones. I suspect silicone orings were rarely selected in those days. I think of nitrile orings as hard - great to grease and use to waterproof rotating switch shafts etc.
Cars etc from late 90s on, I think silicone orings and gaskets (thermostat covers etc) are common (softer, better temperature range, more forgiving providing there is very little movement)

Ordering LR today, wish me and my battered knuckles luck 😀