Hello,
my 4.4 diesel sdv8 is leaking coolant from were the top hose joins the engine does anyone know if I can just replace the o ring seal or is it a new top hose job, thanks in advance

Do you mean the thermostat housing if so don`t buy a new one just replace the `o` ring I had the same problem I bought the housing and it was just an `o` ring. 2017 SDV8 4.4 silicon silver AB
2012 TDV8 4.4 Stornaway Grey AB
2011 TDV8 4.4 Buckingham Blue
2012 VW V6 3.0 Tougreg

not the stat housing the actual top hose were it is fixed to the housing is leaking

Probably just an `o` ring  2017 SDV8 4.4 silicon silver AB
2012 TDV8 4.4 Stornaway Grey AB
2011 TDV8 4.4 Buckingham Blue
2012 VW V6 3.0 Tougreg

been in touch with the parts department local r/r dealers the o ring is part of the hose assembly apparently and of a tapered design and not available seperately £140 + vat is the price they reckon

Give these guys a go.https://www.barnwell.co.uk/o-rings-scotland/ 2017 SDV8 4.4 silicon silver AB
2012 TDV8 4.4 Stornaway Grey AB
2011 TDV8 4.4 Buckingham Blue
2012 VW V6 3.0 Tougreg

I used a 45mm x 3.5mm Viton 75 o-ring.

@GraemeS

Probably a good idea to use Viton as its much more temperature resistant.
I wonder if the original was, given the number of failures of this item?

 “If it ain’t broke, don’t fix it” -where’s the fun in that?

The original seal isn't an o-ring but I don't know of what it's made. The fitting for the top hose is subject to movement when the engine moves in its mounts so the seal wears, whereas the bottom hose can't move as it's braced to the engine. The 45x3.5mm o-ring makes the fitting very snug so perhaps won't move as much as the original, but I'll keep an eye on it as any leaks can be spotted without removing anything.

Now 2 of the 3 spring clamps on the same hose must have lost their tension as on a recent 36 degC day coolant seeped from 2 hoses so screw clamps will be fitted shortly.

Update: The leak wasn't from the spring clamps around the main hose, instead from the screw clamp that I had fitted to my replacement brass spout and small hose which wasn't tight enough. The screw clamps will stay fitted though.

The small hose is part of the main hose which is part number LR080119.

Hello GraemeS,
no, this hose clips on to the plastic elbow, not part of LR080119. It goes down behind the horns.

So it must be the other small hose that is part of the main assembly.

Does it connect to the overflow bottle?