water pump cover threads into block...help!

[Dom]

Hi,

I just attempted to put the water pump cover back on the block (replacing inlet manifold and cover gaskets to eliminate the water in eve).
The bolts that came out were pretty poor condition. One snapped and the others were very old so new gaskets, washer and bolts.
The problem is that despite the bolts screwing in perfectly with no cover on, they get to the tightening stage with the cover on and just lose grip and spin. I have tried a number of bolts and washer combinations and it seems the threads in the block have perished.
Would you guys recommend a helical set in the block to resolve this or is there a preferred method?

By the way, within the 3rd bolt hole at the rear of the pump (in the block), there is a small pool of water at the bottom, is this normal?
When I put a small screwdriver into the hole to fish out the muck, the water on the top of the pump reacted to the movement of the screwdriver leading me to conclude there is an open passage between the bolt hole and the water pump area. Im guessing it wont be a problem when the bolt is sat flush but I did begin to worry about bigger problems. Any advice would allow a peaceful nights sleep!
Thanks.
Dom

[flying farmer]

Helicoiling would be the obvious route to go here, or tapping the hole out to the next size up and using a bigger bolt.

I don't recall the bolt hole going right through into the water way. It may be that someone has drilled and tapped it deeper at some point in the past due to a stripped thread.

Best solution here after fixing the thread is use plenty of gasket compound on the bolt thread to stop any water working its way up the thread.

Neil

[stagmuffin]

as Neil said Dom, helicoil to std size and use a compound liquid from Loctite called 577 its a fit and forget sealant for threads use it on the bolts but not on gaskets, use another medium for them I use it daily for water oil gas and other fuels ,never had a failed joint yet .
steve

[Dom]

Thanks very much chaps.
Dom