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6G Celicas Forums > 6th Generation Celica > Engine/Transmission/Maintenance
jms7436
do you need to replace the head bolts every time you take them out on a 7afe?
Bitter
is the torque spec a lb/ft +degrees of a turn? if so then yes.
garin
it is always a good idea to replace head bolts when they are being taken out, but it is not a must.
jms7436
ya you torque them to 22ft/lbs then 90 degrees and then another 90 degrees... so they need replaced every time??
Bitter
yes
Smaay
it is recommended to replace them, but i re-used them in erynns car and there is no problems. you can mic the bolts and if they are in spec, they are ok to re-use
presure2
OEM head bolts are torque to yeild bolts.
meaning, you tighten them to a specific # value, then another 90*. what that last 90* is stretching the bolt.
any bolt thats torque to yeild should be replaced. (especially if you dont know if they have ever been loosened and reused before.)
IMO reusing them is a bad idea. they are relitivly cheap, and if one were to bottom out from overstreching it and snap, it would get ugly.
Bitter
QUOTE (presure2 @ Jun 27, 2010 - 8:08 AM) *
OEM head bolts are torque to yeild bolts.
meaning, you tighten them to a specific # value, then another 90*. what that last 90* is stretching the bolt.
any bolt thats torque to yeild should be replaced. (especially if you dont know if they have ever been loosened and reused before.)
IMO reusing them is a bad idea. they are relitivly cheap, and if one were to bottom out from overstreching it and snap, it would get ugly.

having dealt with snapped head bolts...they're not THAT bad. you can usually lift the head directly off and then use vice grips to spin them out or a brass drift to get them turning and then out...or very delicately with a sharp steel punch.
jms7436
well the thing is i just rebuilt my 7a and i got performance head bolts. there was no compression so i had to remove the head before it was even started. and when i put it back together i used the same performance head bolts. and now my car is overheating. its boiling the water in the resevior. so i thought that maybe they didn't seal the head gasket... would that be the case or is it prob another problem...?
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