Land Rover Repair/Discovery head bolt stuck
slow mechanic wrote at 2013-03-14 04:11:13
These type of bolts are typically stuck because they are tight. They don't rust into place like an exhaust bolt
I believe in this application it is 15ft/lbs then 90 degrees, and then another 90 degrees turn, The screwing action Stretches the bolt as it is installed.
If you are using a lot of force, like a long handle it can lead to the fastener head failing, or rounding off.
A solution is to heat the bolt head itself. About 200 degrees or less above ambiant should do it. Too hot and you could damage surronding parts/heads or melt the bolt head. Let the heat soak into the bolt. It should expand the bolt and lengthen it slightly. This will reduce the amount of force required to loosen it.
As a last shot removing the head of the bolt is an option, then remove the heads. The bolt will no longer have tension on it and shoul be easily removed. If the bolt head has been damaged by too much torque on say a 12 point socket this would be more expediant then filling down the bolt head to a smaller size. The smaller size would likely round out as well with the same amount of torque being applied to it as a larger head, that still would not let go.
Once again this works for bolts like head bolts that act as springs and the engine and heads contract and expand from heat. Not ones that are rusted or siezed into place.