i was doing a valve job on a geo all was good till i started… tourqen down the headbolts. i broke the last one after doing the three steps in order. Now do i have to replace the head gasket again cuz the head has to come off
If you remove the cylinder head the gasket will have to be replaced again.
While it may not be required, I always coat head gaskets on aluminum head engines with aerosol CopperCoat (both sides). This helps to provide a better seal, fills in any minute pitting that may exist, and helps with heat transfer a little bit.
If it were me, I’d replace all of the head bolts. If one cracked others may not be far behind.
(I don’t know if a Geo uses head bolts of varying lengths but it would be a good idea to verify this and make sure a long bolt is not going into a shallow hole.)
It would be interesting to see if the gasket does fail to seal because it was used twice,the text books say don’t use them twice,I never have,but you can conduct a experiment and try,if you have more time then money.
You should check to see if the bolts are stretch bolts, a one time use item! If so get all new ones next time.