I am in the process of removing my heads and was wondering if it was absolutly nessary to drain the block before I break the head bolts loose? Thanks

 

thru the block drain holes that is...

 

You at least need the coolant level to be below the heads. If not you'll be dumping coolant down the bores and everywhere else

Why not drain the whole system? Engine work is always the perfect time to clean out the coolant system

 

just pulled my heads, and I didn't drain the block first, just the radiator. hope that helps. not a whole hell of a lot of coolant comes out.

 

When I pulled my heads off I had the waterpump off the front of the motor. If I remember correctly almost all of the water was out of the way of the heads. The little bit that did come out was from the very bottom bolts on the heads, meaning the coolant coming out was below the cylinders. If you have the waterpump off just go for it.

 

all of my coolant came out the bottom bolts so did not get in the cylinders but i did make a mess all over the floor, i would suggest draining the block.

 

when i pulled my heads, i had the water pump off. and the drain plugs still in.
some water will spill into the cylinder when you remove some head bolts.
jesse

 

Might as well drain the block.

 

 

If you can, do it. I didn't and coolant went everywhere very bad...