Recent Topics
Oil For High Sustained RPM on BMW S52
by ZEK
Yesterday at 10:41 PM
Chevy brought the blazer back
by WiskyBadger
Yesterday at 10:07 PM
LC20 and uses in modern motor oil
by synman
Yesterday at 10:01 PM
Full Synthetic CJ-4 or > 5W-30 or 10W-30
by LeTempt
Yesterday at 09:57 PM
2018 RAM 1500 EcoDiesel
by OVERKILL
Yesterday at 08:37 PM
Fram SureGrip coating
by mobilaltima
Yesterday at 08:24 PM
Manual transmissioned electric car
by mjoekingz28
Yesterday at 06:45 PM
1991 Toyota Previa New JDM engine Redline
by Kurtatron
Yesterday at 06:26 PM
8 yr old channeling John Bonham
by Toy4x4
Yesterday at 06:02 PM
Traveller nlgi 2
by Spitter
Yesterday at 05:33 PM
Upgrading the Kohler 7000 series air cleaner
by Patrick0525
Yesterday at 05:08 PM
Any nano reefers here?
by RichardS
Yesterday at 05:04 PM
ARC remanufactured Power Steering Pump
by Pajero
Yesterday at 04:58 PM
John Deere "Easy Change" System gimmick
by SnowmanCO
Yesterday at 04:55 PM
Oz Planstic Bag Bans - not so green.
by Shannow
Yesterday at 04:31 PM
help me choose...
by chaindrive
Yesterday at 04:07 PM
France F1 Grand Prix
by DeepFriar
Yesterday at 03:16 PM
Valvoline High Mileage with maxlife tech semi-syn
by bradtech
Yesterday at 03:16 PM
Best additive in oil to clean sludge?
by ffgb
Yesterday at 02:19 PM
Who is a Dirt Track regular?
by thooks
Yesterday at 01:39 PM
Newest Members
ZEK, Dudewayne, kmdz, harborbirds, frascati
65292 Registered Users
Who's Online
23 registered (dishdude, Char Baby, buffalobob, bmod305, David_g, 2 invisible), 493 Guests and 30 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
65292 Members
67 Forums
285749 Topics
4768887 Posts

Max Online: 3590 @ 01/24/17 08:07 PM
Donate to BITOG
Topic Options
#4585186 - 11/26/17 06:39 AM Saab 9-5 Caliper Bracket Bolts
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
I had to take a rotor off of my 05 Saab 9-5 yesterday and got into a confusing situation with the bracket bolts going back on. Torque spec is 103 ft. lbs plus 45 degrees. I took the bolt to 100 (limit) with my clicker torque wrench and then went over to my beam wrench. Torque climbed to about 120 and then leveled off. I was able to get about 20-25 degrees of the 45 (car was on jack stands). I ended up doing all this twice because I didn't like how the quarter turn was going.

I'm wonder if I'm okay with where I left things. I'm short of where the specs are, but I'm a little concerned about the flattening of the torque as I was attempting the quarter turn. Was the bolt stretching or a washer flattening? I haven't seen anywhere where it says that these bolts are single use, but am wondering.

Top
#4585196 - 11/26/17 06:54 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
Ducked Offline


Registered: 10/25/12
Posts: 4366
Loc: Taiwan
If I don't like the way something like that is feeling I stop. Last time I remember doing so was with caliper bolts. I'd rather they be under-torque than broken.

I don't use a torque wrench very often and regard the specs as rather rough guidelines, given all the uncertanties re thread lubing and condition. Brakes seem OK.

Top
#4585211 - 11/26/17 07:24 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
If I didn't break them, they won't snap by themselves, will they?

Top
#4585301 - 11/26/17 08:53 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
mk378 Offline


Registered: 09/27/15
Posts: 1420
Loc: USA
45 degrees is 1/8 turn not 1/4. It would be like the hour hand going from 3:00 to 4:30 on a clock dial.


Edited by mk378 (11/26/17 08:59 AM)

Top
#4585328 - 11/26/17 09:28 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
Ethan1 Offline


Registered: 12/29/14
Posts: 1632
Loc: 'murica
Originally Posted By: ET16
If I didn't break them, they won't snap by themselves, will they?


A stretched caliper bolt absolutely can break while you're driving. It's there for a reason: it gets loaded every time you brake. And if something is tightened to a torque-angle, it's likely to be one-time-use!

Top
#4585366 - 11/26/17 10:05 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: mk378]
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
Originally Posted By: mk378
45 degrees is 1/8 turn not 1/4. It would be like the hour hand going from 3:00 to 4:30 on a clock dial.


yes, my mistake. That's about what I did.


Edited by ET16 (11/26/17 10:10 AM)

Top
#4585367 - 11/26/17 10:06 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: Ethan1]
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
Originally Posted By: Ethan1
Originally Posted By: ET16
If I didn't break them, they won't snap by themselves, will they?


A stretched caliper bolt absolutely can break while you're driving. It's there for a reason: it gets loaded every time you brake. And if something is tightened to a torque-angle, it's likely to be one-time-use!


I thought that this might be the case, but I find no mention of it.

Top
#4585368 - 11/26/17 10:07 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
I'll order new bolts. Should I retorque to a lower value in the meantime?

Top
#4585564 - 11/26/17 12:44 PM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
Johnny2Bad Offline


Registered: 05/20/13
Posts: 1810
Loc: Saskatchewan, Canada
Leave them as is; playing with the bolt stresses it further, and either it's OK at the current value or it isn't. Regardless, it won't be stronger if you go back in there. Replacing them as is your plan will be fine when you get the parts.*

All bolts stretch and all bolts are weakened from the first installation to be weaker on the second (or subsequent) stretches. It's got nothing to do with "Stretch To Yield" except insofar as they are designed to survive only the first stretch, while with other fasteners it's dependent on the actual use at what torque / stretch in what location how closely the fastener is to replacement.

I know that re-using bolts is a time-honoured shadetree tradition, but those who don't mind spending a bit more to be sure of a repair will always replace stressed fasteners in critical locations with new.

* I'm so thankful for the Bolt Supply House here in my city, they have everything .... and I mean everything ... available in stock, just drive and pick them up. There are fasteners purchased from there flying on the Space Shuttle as we speak. Plus prices are better than OEM almost all of the time.
_________________________
'57 FL Straight 50 wt
'90 Miata 1.8L w/Rotrex Supercharger [Mobil1 0W-40]
'96 Ram 1500 [3.7L Mobil1 0W-20 / 1L 15W-50]
'01 PT Cruiser [Mobil1 0W-40]

Top
#4585999 - 11/26/17 06:51 PM Re: Saab 9-5 Caliper Bracket Bolts [Re: Johnny2Bad]
Ducked Offline


Registered: 10/25/12
Posts: 4366
Loc: Taiwan
Originally Posted By: Johnny2Bad


There are fasteners purchased from there flying on the Space Shuttle as we speak.


Think its retired. Probably too late to ask for your bolts back though.

Top
#4586418 - 11/27/17 09:25 AM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
ET16 Offline


Registered: 10/28/08
Posts: 1270
Loc: MD
Folks at Saabcentral say that the bolts are reusable, nothing in the manual about single use.

Before I read the last messages, I went back in and examined the bolts, cleaned them and retorqued to 100 lbs with loctite blue. I have new bolts on order just to be extra safe.

Top
#4586539 - 11/27/17 12:07 PM Re: Saab 9-5 Caliper Bracket Bolts [Re: ET16]
Merkava_4 Offline


Registered: 01/30/07
Posts: 17501
Loc: Clovis, CA
The problem with using a torque wrench on everything is you never develop a feel for what tight is.

I use torque wrenches primarily on applications that involve gaskets.

Top