Cylinder head bolts reuse

I have a few questions on cylinder head bolts:

1. Can they be reused (are they non-stretch)? I am pretty sure the answer is yes but just to confirm

2. Upon reuse, is it necessary to clean the threads? I don't have a table grinder but I could use a hand held 4-1/2" with a wire wheel.

3. Is it necessary or recommended to lube them before setting? If yes, regular machine oil or the engine 5W30 ?

4. Is it necessary or recommended to clean each socket with an air pistol (I think I have a primitive one that came with an air accessory kit) ?

5. I know there is a torque spec floating around somewhere (or is in my Hanes manual) but can you tell what the torquing sequence is? I am pretty sure you're not supposed to torque each to the final torque but do it in stages, bringing each bolt to a certain torque and I think there are three stages.

6. Should I lube the washers ? If yes, regular machine oil or the engine 5W30 ?

 

My guess is that once, something went bad when someone used a bolt twice. The lawyers kicked in and that was the beginning of the end for reuse.

If it hasn't been abused and heavily over torqued, it is still most likely still as good as new. "Most likely," now I sound like a lawyer.

 

I have reused non-stretch cylinder head bolts several times without problems. I use anti-seize compound on all critical bolts. If the threads are in good condition I wouldn't clean them. I'd use compressed air to clean everything before assembly.

By non-stretch bolts I assume you mean bolts that need to be re-torqued on engines with aluminum cylinder heads?

I have a 2nd generation 4 cyl, I've never seen anything about re-torquing the head bolts on this engine so I'm assuming it uses the stretch bolts and re-torquing is not necessary?

 

One of those things clean them up Inspect them if they look good reuse them

Myself if the heads come off either new bolts or studs.

 

It's not just a bean-counter/lawyer thing. Bolts stretch when torqued, and in some specifications this stretch is accounted for. The bolts may become one-time use since a re-torque may not apply the same pressure as when the bolt was new.

If the official Toyota manual says to use new bolts, I would. I don't trust anything Haynes has written for any vehicle past 1980 or so.

 

I too would use new bolts if Toyota specifies them.

 

Don't grease the bolts. It will change your torque reading.

 

New bolts and if using antisieze you need to adjust torque. Your this far along don't cheap out on something like this. It could cause you to have to start over. I never reuse head bolts.

 

I believe there is a measurement in the FSM for stretch. If they fall within spec, reuse them. Tork and twist can be reused as I have done on the Ford 4.6 with zero issues

 

The sevice manual says to check the bolts before reuse and replace any bolts that are damaged:

1. INSPECT CYLINDER HEAD SET BOLT
(a) Using vernier calipers, measure the outside diameter of the bolt thread.
Standard outside diameter: 10.85 to 11.00 mm (0.4272 to 0.4331 in.)
Minimum outside diameter: 10.7 mm (0.421 in.)

Measure all along the bolt threads, if any spots are measured below the minimum replace.

That being said, I would use new bolts.

 

I've never heard of stretch or non-stretch bolts.

I have heard of TTY, or torque to yield bolts. As the name would imply as you tighten TTY bolts to given torque numbers you have placed that bolt in the yielding section of its strength. It's been a while since I've taken mechanics of metals class, but iirc metals get stronger in the yielding section of their strength. A metal that has gone to yield will not have the elasticity to go back to normal. If it where me (an it has been on several other cars) I don't reuse TTY bolts. I've also never worked on a set of heads that the head bolts were not TTY.

 

Use new bolts, cheap insurance, you don't want to have to do this again or cause other damage. You go through the sequence of tightening them to a torque value, as it is listed in the manual, then the final step is tightening them 180 deg, regardless of the actual torque. I was using a 2' bar and giving it my all to get the last 90 deg. Oil the shit out them.

 

http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0070011.pdf

http://www.customtacos.com/tech.old.../06toyrm/06toypdf/06rmsrc/rm2006ta/007012.pdf

Theses are not indicated to be TTY (or stretch, as you call them) head bolts, and can be wire wheeled, oiled (allow excess to drain off), and reused if otherwise in good condition. Clean the threads in the block with the appropriate thread chaser or tap as well, and blow the holes clean. If you wish to buy new head bolts it certainly won't hurt anything but your wallet.

 

as said use new bolts

they cost far less than an engine rebuild

 

Yup agreed. After putting it together it would really be a waste of time and money to pull it apart again to put in new head bolts. BTW if I had to replace the head bolts I would spend a little bit more and get ARP head studs instead but that's me

 

I looked into those when I did my rebuild, seemed overkill for a motor of this size, but they sure wouldnt be going anywhere.

 

That's true, but for me if I have to crack open that block I'm going with quality hardware parts

 

I get a feeling that the whole buy new thing is B.S., partly legal CYA, partly to get you to buy more crap. I think I'm gonna try reusing just as a statement against consumeristic anti recycling propaganda (at least they should be made to be reusable). The rest of my questions remain.

 

Look up yielding region of steel, it may surprise you. Steel gets really strong in the yielding section of its strength and then completely fails. So if you look at a stress curve of steel it will have two peaks, a normal peak and then a second peak (higher then the first) in the yield. Your bolts if TTY are already in the yield section.

With all that being said I did reuse some TTY bolts on the suspension of my GTO. But like others have said, when replacing head gaskets I always got new bolts since it's such a PITA.

 

They are TTY head bolts. They are stretched during the installation process. By a degree which elongates and thins their diameter. Thus the same installation process a second time with not yield the same clamping pressure.

Buy new or buy ARP.

Toyota, in their detailed specs, has a tolerance which is allowable for thickness. If they are to stretched, and thus to thin, Toyota requires replacement. If you can find those specs,and have a caliper then you can test. Otherwise, buy new.