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I have some new drilled/slotted front discs. The service manual says that you *must* replace the break caliper mounting bracket bolts (and washers).

But I have heard some people say that you can re-use the bolts with Locktite. These bolts are only 4-5 months old. But they are torqued to 125 ft-lbs.

What's the word on this? These bolts cost $5+ from the dealer, and you need 8.

TIA for your help.
 

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JimGreen said:
I have some new drilled/slotted front discs. The service manual says that you *must* replace the break caliper mounting bracket bolts (and washers).

But I have heard some people say that you can re-use the bolts with Locktite. These bolts are only 4-5 months old. But they are torqued to 125 ft-lbs.

What's the word on this? These bolts cost $5+ from the dealer, and you need 8.

TIA for your help.
Well, yer not supposed to, but I have. Use the blue locktite, not the red.
 

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What is the diameter and length of the bolt?

125 ft/lbs is a Lot. Sounds like a Torque To Yield fastener. If so, they will have a finite number of cycles (as the manual implies).

Or, they could be a self locking fastener. I'd hope that is the only issue. If so, drilling and safety wiring them wouldn't be a bad idea..

I'm sure that drilling them would be a bear.
 

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I was at the track....

.... (AutoX) and I had to pop the rotors off, do some work and get back on the track. I finished the work put the rotors and calipers back inplace then looked for the torque specs and noticed the "one time" use notice on the bolts. It was a Sunday morning and I didn't have spare bolts. I did have some red Locktite. I used it and reapplied the used bolts and step torqued them to 125 ft lbs. Everything has held together so far. After a hard summer of racing I am waiting new pads and will change the rotors when they come in. Just to be sure I am going to remove the old bolts and put the new ones in for the new season coming up. I got away with it but I wouldn't recommend it.
 

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BrianK said:
What is the diameter and length of the bolt?

125 ft/lbs is a Lot. Sounds like a Torque To Yield fastener. If so, they will have a finite number of cycles (as the manual implies).

Or, they could be a self locking fastener. I'd hope that is the only issue. If so, drilling and safety wiring them wouldn't be a bad idea..

I'm sure that drilling them would be a bear.
Yep, they're torque-to-yield. I'd feel most comfortable replacing them, but that wasn't an option last time. And there is probably some safety margin in there.
 

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Just as another reference.. Ford 302/351 TTY head bolts are rated for 3 torque cycles. They were engineered to last 5. I usually only use them for 2 on my track car. They are *awesome* head bolts for the application - lots of stretch and preload.

I suspect there is a tiny bit of margin built into the caliper bolts. I would *guess* they were engineered for 3 and that 2 is probably okay.

But can you imagine the grief you'll have if you twist the head off of one? :eek:
 

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We go through a lot of TTY bolts at the machine shop. I never reuse a TTY bolt. I have not seen the brake bolts, but 125Lbs/Ft is a LOT of load on a bolt. It has better be the size of a head stud if you are going to be cranking down on it that hard.

Most of the TTY stuff is obvious on say a head bolt, it is threaded much higher than a regular bolt, and the instructions for instance say "torque in three steps at 45, 65, and 85 and then for your final sequence turn the fasterner 90 degrees."

If the bolts are TTY or they just get stresses heavily because of the load it might not be a bad idea to have a set lying around.
 

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Anybody got the part# on those bolts? I'm gonna throw some new rotors on the Z and figured I'd play it safe and replace them.

Thanx.
 

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I re-used them 3 or 4 times on my '99 and took it on the track (Mid-Ohio) several times. I always torqued them properly but never used locktite.
Whenever I took them off, they always were very tight.
I re-used the bolts probably 6 or 7 times on my '94 and also tracked it. Same story. No problems.
Then I didn't know not to re-use them. I know now.
Maybe I just got lucky.
 

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DJ, say it

Ain't so........................:(
Red??????
As in 271???????
You may have to get a torch to take them out.....IF you can..............:roll:
Hope it's not the Perm red............:eek:
 

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Re: DJ, say it

ZO6LS6 said:
Ain't so........................:(
Red??????
As in 271???????
You may have to get a torch to take them out.....IF you can..............:roll:
Hope it's not the Perm red............:eek:
Bah, 271 isn't that scary. With a decent sized breaker bar you're fine.
 

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Re: Mike

ZO6LS6 said:
Easy for you to say they aren't your Caliper bolts!!!!!!!!!:D
Hehe... True, and I do use blue on those bolts... But remember, 271 says "heat or special tools" to remove.
 

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MG

Yep.........how much heat you wanna throw on YOUR calipers?????:D
Special tools??........as in 6" cheater........can you imagine SNAPPING one off in the caliper??.:eek:
All I can say, is keep that crap AWAY from anything on an automobile.......that you don't intend to KEEP it there........for "Like", always:roll:
 

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The bolts don't actually thread into the caliper, but rather the pad abutment bracket, which isn't aluminum like the caliper. Since the threads aren't aluminum, they may not be destroyed when you remove the locktighted bolts, if you can. But I would surely remove the caliper from the bracket before heating the bracket.

I just bought a new pad abutment bracket for $ 27.40. The bolts which attach the caliper to the pad abutment bracket are also TTY, but are touqued to only 23 lbs/ft.

Bob Bishop
 

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Reused the bolts 3 or 4 times on my '96 without any problems. Used red loctitie too. Used a breaker bar to take them off. It was easy.
 
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