Draining the Engine Block

[Gray14]

Can anyone tell me if the cabin heater return hose is the best one to disconnect to drain coolant out of the bottom half of the engine block or is there better hose to disconnect.

TIA   Graham

[Escape]

The heater and it's return hose are too high up, they will not allow you to (easily) drain the entire engine block. If the radiator has a drain, that will be the lowest point in the system. But some coolant can still remain trapped in the engine block. You can get more out by applying (low) air pressure to one of the top hoses, for example into the small bleed hose from the expansion tank (and blocking the other side).

If you don't need to drain the system completely, you can get most of the coolant out by applying pressure into the expansion tank (cap on of course) and putting the other end of the bleed hose in a container. I always drain the coolant this way when changing a timing belt, water pump or such, very easy and very little spillage. Works on most engines, you just need to find the right hose somewhere at the top.

 

[EXCEL V8]

Also see reply on the other forum 😁

Pete

[Gray14]

Thanks Pete and Filip. Found a picture showing the location of the block drain/blanking plug located below the exhaust manifold at the rear of the block, looks hard to access.  Read on a Jensen Healy post that this is 0.64 inches between Hex sides. Location shown in pic:

Edited June 4 by Gray14

[Escape]

Yes, those drain plugs are hard to get to. Which is why they are rarely used unless you really need to. 😉