Necessity of Loctite on Brake Caliper Bolts?

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This is a question that I have had for quite some time.

On the Hondas and Toyotas I have worked on, no where in the shop manual does it state to use Loctite on the caliper bracket to knuckle bolts or on the caliper assembly to bracket bolts. And to this day, I have never had an issue with the bolts backing out, knock on wood.

However, back when I had my Saturn, I remember that GM recommended that threadlocker be used on the caliper bracket to knuckle bolts. Of course, I never used any when I reassembled mine since whoever watched over me at the time said it was not needed. I never had any problems, either.

If you google "loctite on brake caliper," you will come across a number of threads about this topic, almost exclusively on GM forums. There are a number of posts about brake calipers falling off due to a tech's failure to use loctite. It is difficult to believe that floating calipers are significantly different on GM cars, and require the use of threadlocker for the bolts to not back out. (For instance, the only difference I remember about my Saturn's calipers were that the slide pins bolted the caliper to the bracket, unlike most other cars where the slide pins remain in the bracket itself.)

With that said, these are the questions that I have:

1) Is Loctite really needed for brake caliper bolts?

2) Is it good insurance to put some on anyway? If so, would Loctite blue be a good product to use for this?

3) On the GM applications that require it, what is the origin of the requirement? How is there more stress on the caliper bracket bolts in those applications? What makes them more prone to backing out?

4) Is Loctite red the best product for the bracket to knuckle bolts? I've been told that heat is not always needed for removal, and is more critical on smaller bolts where breakage is a greater concern.

Let's discuss.

Thanks!
 
Brake bolts need Loctite?

Not on my Chrysler. Never used it. Never had an issue. Odd. Must depend on designs.
 
shocked.gif
How timely........

I just did the front pads, caliper bolts & rotors on my Saturn SL2!

I am hearing some odd noise when stopping now, like something's loose. No Loctite on the new bolts.

Think I'll leave the Saturn at home today & drive in the GTO, then check it out when I get home...
 
My recent experience is limited to Corvette brakes with aluminum steering knuckles. I've always used a Loctite product when reinstalling my caliper brackets with the OEM bolts when changing out rotors. (Factory service manual says to discard the old bolts and install new one which come with an OEM-applied thread locker.)

Since I auto-x and track my Corvette, I use Loctite as an added precaution due to the heat and vibration the calipers generate during hard use and the higher expansion rate of aluminum (versus cast iron). If the steering knuckle were cast iron as was the case with the older '65 to '82 Corvettes, I probably wouldn't use a Loctite product unless the Corvette was a dedicated track car.

If you're going to use Loctite "Red" (271 or 272), you should apply some heat to the bolt prior to removing it (although I'm sure someone out there has used gorilla torque to remove bolts without applying any heat).

Hope this helps!
 
If it specs the use of it then by all means use it. True its probably a disclaimer for safety reasons but you never know.
Try the new Loctite blue tape it works well on larger diameter bolts.
 
Believe the bolts on my BMW are specced to use.

In fact you are supposed to change the bolts themselves!
 
I believe that on my Hondas and other vehicles, using the proper torque on the caliper bolts is sufficient. A touch of Loctite "blue", however, gives me a bit more confidence as my wife and kids drive my vehicles in both city and interstate situations. Having done my own brakes for 30 years, (purely as an amateur), without a failure, I don't see a downside to using it.
 
More than likely the factory does it as a quality control thing, then everyone since then says well jeez there was already some on there.
 
Never thought about putting it on the caliper bolts, because I would never use loctite on anything I plan to remove repeatedly. My brakes will tell me when they don't like what I've done, ist usually not enough grease.
 
Originally Posted By: MrBeachcomber
My recent experience is limited to Corvette brakes with aluminum steering knuckles. I've always used a Loctite product when reinstalling my caliper brackets with the OEM bolts when changing out rotors. (Factory service manual says to discard the old bolts and install new one which come with an OEM-applied thread locker.)

Since I auto-x and track my Corvette, I use Loctite as an added precaution due to the heat and vibration the calipers generate during hard use and the higher expansion rate of aluminum (versus cast iron). If the steering knuckle were cast iron as was the case with the older '65 to '82 Corvettes, I probably wouldn't use a Loctite product unless the Corvette was a dedicated track car.

If you're going to use Loctite "Red" (271 or 272), you should apply some heat to the bolt prior to removing it (although I'm sure someone out there has used gorilla torque to remove bolts without applying any heat).

Hope this helps!


Locktite here seems wise. For most cars, I never use it or even consider it.
 
On the very first brake job I did on my '97 SAAB 900, I didn't use Loctite.

The next morning, a caliper bolt when flying as I decelerated down the interstate off ramp... Thankfully, I still carried a full toolbox in my trunk (gas was still just around $1.40 a gallon) so all that day I had to jump out and retighten the remaining bolt after so many stops, as you could hear the caliper start to wobble as that last bolt backed out
 
Originally Posted By: The Critic
Garagejournal thread:

http://www.garagejournal.com/forum/showthread.php?t=162529

Over there, there's an overwhelming recommendation to use it for insurance.


I wouldn't call it "overwhelming." A couple people more have said use it.

Here's the breakdown in the GJ thread as of now:
Use it: 11
Don't use it, or I never have used it: 9
Do what manufacturer says: 3

Personally, I fall into the camp that says use it if the manufacturer says to. I would guess the anecdotes about bolts coming out are more due to incorrect torque than a lack of thread locker.
 
Not only do I not use it, I use neverseize because of the horrible corrosion we get.

I did have one bolt back off 22 years ago on my 85 Omni.
 
I use it, mostly because GM tells me to and their service instructions are often the most thoughtful.

Specifically, they call for Loctite 272, which is medium-high strength, high temperature. Unlike 271 (high strength), hand tools can break the bond of 272.

In my Peugeot, there's a metal plate that goes under the bolt heads. After tightening, you're supposed to bend the plate in a manner that obstructs the hex head from turning. It's a pain in the rear to bend those things, so I use the Loctite 272 instead. It works great.
 
Originally Posted By: BrianWC
On the very first brake job I did on my '97 SAAB 900, I didn't use Loctite.

The next morning, a caliper bolt when flying as I decelerated down the interstate off ramp... Thankfully, I still carried a full toolbox in my trunk (gas was still just around $1.40 a gallon) so all that day I had to jump out and retighten the remaining bolt after so many stops, as you could hear the caliper start to wobble as that last bolt backed out


This is obviously from a bad job, not a lack of Locktite.
C'mon now... the next morning?
 
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