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View Full Version : When is it OK to re-use head bolts?


Aerovette
06-26-2021, 11:26am
Replacing the head gasket on a 2.2 inline 4 cylinder Rodeo. I have trusted Haynes manuals for a long time. It says to create a cardboard template and place the head bolts in it so they go back in to the same location.

But...the gasket kits on line all say to replace the head bolts.

I have re-used head bolts on my older cars, but these bolts are torqued using torque angle specs and not actual torque so maybe that makes a difference.

Stevedore
06-26-2021, 11:59am
I changed a lot of head gaskets in my younger days, & never replaced the bolts. I think some, if not all, newer bolts are torque-to-yield, & shouldn't be reused.

I'm old, & this is just one of many things that have likely changed since I thought I knew everything... :rofl:

DJ_Critterus
06-26-2021, 12:25pm
IF they are stretch bolts you definitely don't re-use them.

Datawiz
06-26-2021, 12:42pm
IF they are stretch bolts you definitely don't re-use them.

This.

Buy ARP bolts to replace them, and you won't have to replace those. :yesnod:

Rodnok1
06-26-2021, 12:47pm
Replacing the head gasket on a 2.2 inline 4 cylinder Rodeo. I have trusted Haynes manuals for a long time. It says to create a cardboard template and place the head bolts in it so they go back in to the same location.

But...the gasket kits on line all say to replace the head bolts.

I have re-used head bolts on my older cars, but these bolts are torqued using torque angle specs and not actual torque so maybe that makes a difference.

On a Redeo? I would reuse them as new bolts would cost more than its worth. :slap:

Datawiz
06-26-2021, 12:53pm
On a Redeo? I would reuse them as new bolts would cost more than its worth. :slap:

:rofl:

If he fills up the gas tank, he doubles the value of the car. :lol:

DAB
06-26-2021, 12:58pm
French used car salesman: but sir, it has fresh head bolts!

Aerovette
06-26-2021, 3:01pm
IF they are stretch bolts you definitely don't re-use them.

How can you tell?:island14:

Y2Kvert4me
06-26-2021, 3:11pm
How can you tell?:island14:

TTY bolts typically have a bulge just under the head of the bolt.

58370

58371


:cert:

Bill
06-26-2021, 4:58pm
TTY bolts typically have a bulge just under the head of the bolt.

58370

58371


:cert:

Thanks, I was wondering that, too.

markids77
06-26-2021, 6:06pm
How can you tell?:island14:

If the manual specifies tightening to a torque value then rotating the bolt x degrees, that is torque and turn (torque to yield) however the fastener is configured. Re-use and re-stretch will likely snap them. If it does not they certainly have less clamping force than when first installed.

DJ_Critterus
06-26-2021, 7:18pm
Barton Family used car salesman: but sir, it has fresh head bolts!
UniqueDoug

Aerovette
06-27-2021, 11:10am
TTY bolts typically have a bulge just under the head of the bolt.

58370

58371


:cert:

I was today years old when I learned these bulges were not for aligning a part so it is centered on the holes. :cert:

Aerovette
06-27-2021, 11:12am
If the manual specifies tightening to a torque value then rotating the bolt x degrees, that is torque and turn (torque to yield) however the fastener is configured. Re-use and re-stretch will likely snap them. If it does not they certainly have less clamping force than when first installed.

Exactly my fear. I bought new bolts, so the job is on hold until they get here.

Torque is 18, 90 degrees, 90 degrees, 90 degrees.

Rodnok1
06-27-2021, 11:46am
Exactly my fear. I bought new bolts, so the job is on hold until they get here.

Torque is 18, 90 degrees, 90 degrees, 90 degrees.

And it'll still be a blown up POS in a couple months.. Just with new head bolts. :seasix:

Strats-N-Vettes
06-27-2021, 12:12pm
Clean/tap/chase female threads...blow out to ensure no debris settled at bottom of threads to prevent accurate torqueing or TTY.