: Head bolt reuse? thread sealer



edb150
05-20-10, 12:11 AM
Anybody ever reused a head bolt or replaced the sealant? I have a customer whos car just had head gaskets and headbolts replaced but the threads pulled. I will be inserting it and the customer is wanting me to save some money somewhere since he already spent for a failed repair. The bolts are new and used once so the sealant is obviously gone. Any ideas on a sealant? I suggested we replace them and explained the theory behind replacing them because of the sealant but money is the concern at this point and I am trying to help him out.:rant2:

Ranger
05-20-10, 01:02 AM
Joe, I recall our old Guru (A GM powertrain engineer) saying never reuse head bolts. I understand his point, but it would be penny wise and dollar foolish, not to mention a damned shame to have it fail a third time.

YueIBM
05-20-10, 03:57 AM
The GM service manual says to use new bolts due to sealant, but there might be another reason. Not sure if these bolts undergo plastic deformation (doesn't return to unused length after being torqued). If it gets longer after use, you'll have to stretch it out even more, and possibly to where it almost breaks to get the same tension/clamping force on the second installation - and the 22lb-ft +60-degrees x3 torque procedure would be off. http://www.srs.org/professionals/glossary/images/gloss7.gif

If you can compare an old bolt with a new, unused one and see they're different lengths, that should convince him to get new ones.

zonie77
05-20-10, 10:46 AM
Joe, I recall our old Guru (A GM powertrain engineer) saying never reuse head bolts. I understand his point, but it would be penny wise and dollar foolish, not to mention a damned shame to have it fail a third time.

:yeah:

If you redoing it it's just silly to save that little bit and take the chance. If he doesn't put new bolts in DO NOT guarantee the job.

tateos
05-21-10, 12:33 PM
Or better yet, use Jake's studs

stoveguyy
05-21-10, 12:54 PM
interesting topic. are all bolts exactly the same length when new? say 6.250 long? so a used bolt will be 6.250 if it does not deform or 6.281 if it does deform and all the bolts will be 6.281 than? 2nd point. who did the 1st attempt at fixing the headgaskets? a shop? do they have a warranty? or was it a friend of a friend who did not offer a warranty?

NHRATA01
05-21-10, 01:30 PM
No,no,no. The headbolts are torque-to-yield as indicated by the angle specified in the torque sequence. What you are doing is stretching the bolt to achieve the correct clamping force, once loosened they will never have the original strength. Never, ever, reuse a torque to yield bolt on any application. They are 1 use only.

Submariner409
05-21-10, 03:54 PM
^^^^^ Truth

GM ducks the block/thread/head problems, BUT the manuals specifically say to use new head bolts during an overhaul or top overhaul.

Cylinder head removal and replacement, QUOTE: "Important - do NOT reuse the cylinder head bolts......."

zonie77
05-21-10, 03:56 PM
The N* head bolts are not TTY. They are regular normally reuseable bolts with special coatings on them. This has been beaten almost to death before. On test stand engines the bolts and HG's were sometimes reused but they weren't concerned with longevity in a driver, they were regularly pulling the heads to check the engines (this is per old guru).

A side note on the head bolts...you can remove and reinstall them as long as the engine is not run long. The coatings cure from heat.

zonie77
05-21-10, 04:07 PM
Anybody ever reused a head bolt or replaced the sealant? I have a customer whos car just had head gaskets and headbolts replaced but the threads pulled. I will be inserting it and the customer is wanting me to save some money somewhere since he already spent for a failed repair. The bolts are new and used once so the sealant is obviously gone. Any ideas on a sealant? I suggested we replace them and explained the theory behind replacing them because of the sealant but money is the concern at this point and I am trying to help him out.:rant2:


Was the original repair done without inserts? There have been a few people that thought they had good threads a long time ago someone had the last thread fail on the last tightening sequence! He tore it apart and inserted them all.

Submariner409
05-21-10, 04:19 PM
I believe you are misinformed. From the Seville 2002 Factory Service Manual, Volume 1, P. 6-445/6: (all punctuation format is exactly as shown in the GM Service manual. There is certainly no gray area here.......)

Cylinder head installation - left
Tools required:
J 36660-A Torque Angle meter
1. Ensure all the cylinder head locating pins are securely mounted in the cylinder block face.
Important: Failure to remove all the old thread sealant material from the cylinder block could cause false torque readings.
2. Ensure any old thread sealant material is removed from the cylinder block head bolt holes in the cylinder block.
3. Install a new cylinder head gasket using the deck face locating pins for retention.
4. Align the cylinder head with the deck face locating pins.
5. Place the cylinder head in position on the deck face.
Important: DO NOT reuse the old M11 cylinder head bolts.
6. Install new M11 cylinder head bolts in the cylinder head.
7. Install the M6 cylinder head bolts at the front of the cylinder head.
Notice: Refer to Fastener Notice on page P-9 in Cautions and Notices.

.........the torque sequence then is presented.

tateos
05-21-10, 11:35 PM
I think Zonie is saying that you should not re-use the bolts, but not because of the actual metal in the bolts is somehow compromised, but because of the sealant that comes on the threads, once installed and cured. In the end, the correct answer for the OP is do not re-use the bolts.

edb150
05-23-10, 12:31 AM
To answer some questions the hg and bolts were run for less than an hour and i understand the bolts themselves would be reusable if the sealant was not important. The head bolts as I understand are the same type as the main bolts, which the service manual does not say to replace.I guess I am wondering if the sealant can be duplicated. Its easy to throw money at the car when your not the one paying for it but my customer is trying to save some cash somewhere as his trip to Cadillac paradise has been very expensive. He just bought the car for 6k and now is going to spend another 2k.

Ranger
05-23-10, 09:24 AM
I guess I am wondering if the sealant can be duplicated.
Joe, I seem to recall our old Guru saying no to this question. I suspect if it was a simple matter of Loctite, the FSM would say so, but I have to admit, I've always wondered why that would not work. After all, don't Timeserts and Norm's inserts come with Loctite? If the bolts are not TTY and the thread locker is the only factor I suppose you could give it a shot as long as the costumer is willing to take the gamble. By the way, how much are we talking about for a set of head bolts?

Submariner409
05-23-10, 09:28 AM
2002 STS, Rock Auto, Fel-Pro head bolts with sealant and washers, $31 a head.

1998 STS, $26 a head.

Ranger
05-23-10, 09:43 AM
That's not worth the gamble.

Necrosan
05-23-10, 05:17 PM
I don't see any real choice but to buy the bolts.
A shame the threads didn't hold the first time; I _KNOW_ you don't wanna pull the heads off the same car 3 times.
Your options are pretty much reuse the old and give NO guarantee whatsoever or buy the new.
I know I hate losing money on work... especially when $70 would have ensured no problems to begin with.

edb150
05-23-10, 09:46 PM
70 bucks for both sets , felpro . I already put it together with new ones but I guess i still am wondering what the sealant is

Ranger
05-23-10, 09:54 PM
Joe, I think the sealant is merely a thread locker similar to Loctite.

tateos
05-24-10, 02:01 PM
Based on my observations, I think it's more than a thread locker - I think it's also a thread sealer - sort of like a pipe thread sealant - like Rector seal

edb150
05-26-10, 12:01 AM
I actually talked to someone at felpro and yes its just thread sealant like the parts store sells. Thanks for the info everyone. So many customers want me to save money somehow as if I have a magic wand to wave over it but in the end there just are no shortcuts with one of these head gasket projects.:tisk:

marcusmo172
10-23-10, 05:25 PM
can any one tell me where I can rent the J 36660-A torque angle meter. I have looked every where and it is expensive to buy. Or can you torgue the new bolts down with out the tool. I would appreciate some feedback. I am at a stand still and as much work this engine is. I don't want to go back and re do...Thanks

Submariner409
10-23-10, 07:07 PM
can any one tell me where I can rent the J 36660-A torque angle meter. I have looked every where and it is expensive to buy. Or can you torgue the new bolts down with out the tool. I would appreciate some feedback. I am at a stand still and as much work this engine is. I don't want to go back and re do...Thanks

The bolts have 6 flats (or 6 points) - 6 flats X 60 degrees = 360 degrees. Torque to initial setting, degree to magic marker reference marks.

Did you insert all 20 holes ???

Carroll Cadillac
10-24-10, 01:09 AM
can any one tell me where I can rent the J 36660-A torque angle meter. I have looked every where and it is expensive to buy. Or can you torgue the new bolts down with out the tool. I would appreciate some feedback. I am at a stand still and as much work this engine is. I don't want to go back and re do...Thanks

There is no reason to rent a torque meter, they in two types digital or manual the manual one is the most acurate and lasting.
The digital meter can run as much as 500.00 and the manual turn is around 17.00 and can be purchase at your local MCK tool supply.

zonie77
10-25-10, 12:43 PM
I've done several HG jobs and used the magic marker technique.

I know this is an old resurrected thread but the info I gave about bolts and sealants came from the old guru. His posts are gone so a lot of what he said is now handed down the old, old way. We storytellers are an important part of the tribe!

His info was: it was more than loctite and the bolts should be replaced if used for more than a short while. He also said they normally reused HG's and bolts on test engines. If you were testing something and planned to run the engine for a short time that would be acceptable, running it for years in your vehicle would warrant new bolts.