Head bolt leak.

[Ian Williams]

This is an interesting thread for me, when I first got involved with sevens I only ever fitted head gaskets with a very light smear of grease, never with any problems. More recently I have been experiencing issues with failures between 2 and 3 as well as water seepage into the bores, I should add that some of these are gaskets fitted by others. There are two issues being discussed here, the first is leaking studs, a cure for that is always fit new studs with a sealant, I know some suggest loctite, I found success with a good pipe thread sealant. The other issue is water seeping across the gasket from waterways, this is a real problem if it goes unnoticed and water is getting into the bores, a lot of damage can occur throughout corrosion. I have suspected that the modern gaskets we get use a different composite to those from 30 or 40 years ago and that possibly this fails to compress as well under our modest torque settings. It is also vital that the head and block faces are completely flat, many blocks seem to have sunk slightly where they get extremely hot between 2 and 3. I have tried a few things to seal the gaskets but Hylomar spray has been the most successful for me. Now I fit a fair number of gaskets, however no where near as many as a well known contributor here who's opinion I trust, he tells me that he only ever fits gaskets with copper slip with complete success. It would be informative to hear from other's about success or failures.