Hi Guys,

So my new to me L405 is exhibiting a coolant leak down the back of the bell housing. It's been pressure tested and holds pressure fine but still a persistent leak.

So I'm comprising a list and will need some help a long the way but will update to help others in the future. Note I'm not a mechanic, but have owned 20+ BMW's in the past so am well versed in DIY. If beneficial I will attempt to take pictures along the way to help others looking to carryout this themselves.

So the part numbers I currently have are:

LR023072 - EGR Cooler to EGR Valve Gasket
LR023100 - EGR Cooler Gasket
LR022777 - Exhaust Manifold to EGR Cooler Gasket (Cooler Side)
LR023022 - Exhaust Manifold to EGR Cooler Gasket (Exhaust Side)
LR022718 - EGR Cooler Outlet Hose (Apparently this is prone to snapping)
LR113003 - Oil Filter Housing Gasket
LR023141 - Crossover Pipe and Thermostat Housing Gasket x2

So where I need help:
I'm looking to replace most of the coolant hose O-rings as a whilst I'm in there.
Search shows the larger ones are 45 x 3.5/4mm Not sure which to buy. Also smaller I believe are 8.73 x 1.78mm For the oil cooler. does anyone have a comprehensive list that I can use to replace all the little and large O-rings with Viton along the way?

Thanks in advance!
Phill