Expansion bottle filling up

[stevep]

Recently refitted my YPVS engine after a top end rebuild , soon after starting the expansion bottle fills to the brim and starts leaking out , I did check the level in the bottle was correct first, any ideas , head gasket maybe

[bazzer5115]

Yep,head gasket.
Make sure head flat,400grit wet and dry on piece of glass,
Some use a little sealer,nip barrels down then torque head,then tighten barrels down(the base gaskets are more forgiving than head gasket on any slight height differences)
Start engine and gently warm for a couple of minutes(hand hot on barrels)with no water in.
Allow to cool,re-torque head then add water/coolant.
Run a couple of times to remove any trapped air.
Should be fine,don't forget the washers under the head bolts or else the shouldered bolts bottom out before head tight on skimmed heads(I know I"ve done it!!!)

[sandpiper]

hi before stripping head off just take off radiator cap run on tick over till warm to expell air locks this may be pushing your water out, refill to level try again if water still keeps coming out then head gasket is favourit. did it not do this till you top ended her?? other issues is cracked liners or head but if run ok before then these are not the issue good luck.

[stevep]

Thanks for the info guys , will check for airlock first , I reckon its the head though .