thread lock on caliper bolts?

blurry

Original poster
Member
Sep 7, 2012
22
Our trailblazer gets used full time during the winter and part time during the summer. Every year about this time i go through the truck to make sure everything is good for the winter (mostly because I'm a wuss about working in the snow!). take it out and the brakes feel really mushy. No worries, every year I go through the suspension and brakes which includes cleaning the caliper pins and re-lube them. three wheels down and brakes look great. get to the fourth wheel and the pads are stuck, end up beating them out with a hammer. go to unbolt the caliper bracket and wow, those bolts are on there. finally break them loose and they fought the whole way out. look at the bolts and there is a ring of lock-tite on both of the bolts! clean the bolts, hardware, grooves in the caliper bracket, slider pins and put light coating of brake lubricant on the hardware... and the pads dont fit...ended up having to grind 1/16th to 1/8" off the pad ends to get them in there so they could move just a touch.

so the back story is that last year my wife was 3 hours from home and things went south. she called in a panic on the way to a meeting that the brake went to the floor and there was all sorts of racket from the back of the truck. She was in view of a Midas so the truck went there and they gave her a ride to the meeting. Midas put a new caliper, rotor, and pads on this corner after a catastrophic failure (which I have yet to have fully explained to me, it involved a broken rotor and caliper that was in pieces). apparently they beat the pads in and put lock-tite on the caliper bracket for a staggering $750.

Anyone else ever put lock-tite on a caliper bolt? I just use a torque wrench :smile:
 

MAY03LT

Member
Nov 18, 2011
3,420
Delmarva
blurry said:
Anyone else ever put lock-tite on a caliper bolt?

No way! In fact, I remove the loctite when I reinstall the brackets on these trucks. IMO it's unnecessary considering the 148ft/lb torque spec.

Also, I've seen the same "tight fit" issue with aftermarket pads and have had to grind off some of the coating for a better fit.
 

Boricua SS

Member
Nov 20, 2011
3,080
Ohio
never used it in my 10 years of workin on vehicles...
 

McGMT

Member
Jun 17, 2012
621
I had to use blue loctite on the caliper mount bolts on my wifes old 98 Regal GS she had. One time she had one of the bolts work its way out and she couldn't back up or the caliper would kick up and wedge against the inside of the rim. Had to go get a new bolt n stick in it. Never put one on since without a little drop.
 

Sparky

Member
Dec 4, 2011
12,927
I've never used locktite on any of my brake hardware. Heck in the past I've simply used the german torque spec gootentite (say it out loud :biggrin:) because I didn't used to own a torque wrench. Actually to be quite honest I still do a lot of work using that. I should probably use my torque wrench more, but so far none of my suspension, brakes, or drivetrain have fallen off so I must be getting it tight enough :rotfl:

Well, except those darn endlinks. I don't think those can ever be tight enough :hissyfit:
 

Lima Tango

Member
Dec 4, 2011
242
I use a dab of blue loctite in addition to my torque wrench. I have seen the aftermath of calipers falling off and it was nasty enough that I will always use blue loctite as insurance.
 
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JerryIrons

Member
Dec 20, 2011
434
No I never use loctite on my bolts in almost 30 years of working on my own vehicles. Actually I use some antiseize since I live here near buffalo in the rust belt with snow and ice 8 months out of year haha. Then the next time I need to change brakes the bolt actually comes off instead of snapping in half. I rotate my own tires and always check over my brakes and never had anything loosen up. I'm sure other people will not agree with me on this. You are right those back bracket bolts take some work to get off, between the yellow loctite and 150 lbish torque setting.

Just have people report to you when they hear a new clunk or rattle. Easier said than done sometimes I know.
 

DARKASS04EXT

Member
Nov 21, 2011
193
Just the other day I was actually thinking about putting locktite on my rear caliper bolts. I was coming back to DE from Mass, and as i came into DE my rear brakes started makes horrible noises. Luckily i was only 10 min from home when it started, I made it home and left it for the next day. I come out and pull the wheel off to find that a caliper mounting bracket lost a bolt. The sound was from the brake caliper hitting the rotor as it lifted on and off the rotor. Having the 22" SS repo's, the brakes had enough room to pivot back n forth w/o hitting the wheel. This makes the 3rd time i lost a bolt out of the rear calipers. Ive lost 2 caliper bolts (1 off ea side) and 1 caliper mounting bracket. I torqued them to spec(cant remember what was spec now) I cant figure out why ive had such a problem with them. The new bolts from the dealer actually had some goo on the bolt, so im assuming that was locktite but not sure.
 

blurry

Original poster
Member
Sep 7, 2012
22
interesting. I also use touch of anti-seize along with a torque wrench. the winters here make bolts hard to get off.

educational to hear that folks are putting lock-tite on brake HW.
 

Mooseman

Moderator
Dec 4, 2011
25,344
Ottawa, ON
I had a bracket to hub bolt work its way loose and fall off on my Montana van not long after I did a brake job on it. And I'm sure I put them good and tight. Closest place was a stealership who charged me like $35 for the bolt plus labour. I will use blue loctite from now on.
 
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Bub

Member
Nov 21, 2011
159
Lima Tango said:
I use a dab of blue loctite in addition to my torque wrench. I have seen the aftermath of calipers falling off and it was nasty enough that I will always use blue loctite as insurance.

happened to me, thought i had the caliper bracket torqued right but it worked itself out and the bracket quickly upgraded me to a 3-piece rim....now i always use blue loctite with that kind of shit
 

Sparky

Member
Dec 4, 2011
12,927
Good point about the rust. Rust is probably my locktite :rotfl:
 

meerschm

Member
Aug 26, 2012
1,079
Did you open the bleed valve and push the piston back? that made room for me to put shoes on.

and I did put a dab of blue locktite. probably not needed, but seemed like a good idea.
 

blurry

Original poster
Member
Sep 7, 2012
22
meerschm said:
Did you open the bleed valve and push the piston back? that made room for me to put shoes on.

and I did put a dab of blue locktite. probably not needed, but seemed like a good idea.

I usually crack the bleeder when pushing back pistons. The pads they put on just needed some grinding :smile:

Interesting to hear on the locative, not something I have ever done.
 

Mooseman

Moderator
Dec 4, 2011
25,344
Ottawa, ON
That is one of the biggest myths about ABS. You do not need to open the bleeder to push the piston back. It's not in any manual, including GM's.
 

Sparky

Member
Dec 4, 2011
12,927
Still it is easier to compress the pistons with the bleeder cracked vs pushing the fluid all the way back through the lines. I did have to push my front passenger side pistons back with the bleeder closed however since the bleeder is seized up. I didn't feel like busting it and having to replace the caliper that day.
 

AV8ER

Member
Apr 19, 2012
260
Easiest way to push the pistons back is to grab a good'ole trusty c clamp and slowly push the piston back. I recentally replaced the rear pads and didnt use any loctite. One side both bolts came off way easy the other side took a big cheater bar to get off.
 

blurry

Original poster
Member
Sep 7, 2012
22
Mooseman said:
That is one of the biggest myths about ABS. You do not need to open the bleeder to push the piston back. It's not in any manual, including GM's.

Any idea on what started this myth?
 

JerryIrons

Member
Dec 20, 2011
434
I'm not so sure it's a myth. The idea is to prevent contaminants in the old brake fluid, backflowing into the ABS unit and screwing it up. Personally I have always just used the c clamp and never opened the bleeder screws. You are right in the service manual it doesn't mention anything about opening up bleeder screws when compressing those pistons. But I wouldn't be surprised if other mfrs recommend differently.
 

meerschm

Member
Aug 26, 2012
1,079
probably a good observation by anyone who has bled the brakes, or changed the fluid. first bit can have a batch of nastyness in the fluid. I would not doubt that stuff could mess with the workings, esp anti-lock and traction control modulation. I cracked my bleed valve for the pad change, since I was going to pass a bit extra through anyway. ( I was going to change the fluid, but ended up dumping a good amount on the driveway, did not have the motive tool sealed properly. (a quick flush with some degreaser hopefully kept most of my paint on.)
 

McGMT

Member
Jun 17, 2012
621
meerschm said:
probably a good observation by anyone who has bled the brakes, or changed the fluid. first bit can have a batch of nastyness in the fluid. I would not doubt that stuff could mess with the workings, esp anti-lock and traction control modulation. I cracked my bleed valve for the pad change, since I was going to pass a bit extra through anyway. ( I was going to change the fluid, but ended up dumping a good amount on the driveway, did not have the motive tool sealed properly. (a quick flush with some degreaser hopefully kept most of my paint on.)

If there is a bunch of junk in your caliper then you have a bad seal somewhere.... The fluid in the caliper is the same as what is in the lines and all, that is the idea being flushing. As long as the caliper is good and the seals are uh well sealed haha then there is no more junk in that fluid than the rest of it.
 

MAY03LT

Member
Nov 18, 2011
3,420
Delmarva
My work had enough cases where they had to replace an abs module immediately after a brake service that cracking the bleeders is now mandatory. The best part was, every case was with a GM vehicle. Since the policy was put into force there hasn't been a single instance where the abs module had stuck/sticky valves after a brake service.
 

Sparky

Member
Dec 4, 2011
12,927
McGMT said:
If there is a bunch of junk in your caliper then you have a bad seal somewhere.... The fluid in the caliper is the same as what is in the lines and all, that is the idea being flushing. As long as the caliper is good and the seals are uh well sealed haha then there is no more junk in that fluid than the rest of it.

Not exactly. Brake heat will work on the fluid in the caliper and can make it get a little funky over time. I've seem some pretty nasty stuff come out of the bleeder for the first pedal press or two then clear up.
 

meerschm

Member
Aug 26, 2012
1,079
Sparky said:
Not exactly. Brake heat will work on the fluid in the caliper and can make it get a little funky over time. I've seem some pretty nasty stuff come out of the bleeder for the first pedal press or two then clear up.

Brake fluid is not like fuel, with return lines. in and out is the path, and not all that much.


next time you do brakes, get some tubing to fit over the bleed valve, put the C clamp (or tool) in place, crack the valve and then push the piston back. close the valve before removing the C clamp and you should not get any air back in the if you have any time at all on the fluid, you will probably not be too impressed with the clarity of fluid you get. might be motivated to change all the fluid. ( if the bleed valve has not moved for a while, you might want to crack it loose first using a six sided socket.)

I have one bleeder screw I think the dealer changed during a brake job, same size wrench, but the cover does not fit. would hate to mess one up using a crescent wrench in the driveway.

I also have a couple of these I got with a bleeder:
http://motiveproducts.3dcartstores.com/Single-Power-Bleeder-Catch-Bottle-1810_p_90.html
 

JerryIrons

Member
Dec 20, 2011
434
Yeah I have bled my brakes enough when doing brake jobs that the brake fluid that comes out of the bleeders looks *alot* different from what you poor into the master cylinder, enough to make me wonder just what has happened to it, and how does it affect current braking operations, etc.
 

OldSVTGuy

Member
Jan 1, 2013
3
I have had two MC's fail by pushing the caliper piston back. Since that time, I always loosen the bleeder screw when compressing the caliper piston and have not busted a MC since.

Food for thought.

- - - Updated - - -

I have had two MC's fail by pushing the caliper piston back. Since that time, I always loosen the bleeder screw when compressing the caliper piston and have not busted a MC since.

Food for thought.
 

IHZ05VOY

Member
Dec 8, 2011
73
I do remember that when Roadie help me change my OE rotors and brake pads we encountered lock-tite's on the rear.
 

Busterbrown

Member
Dec 4, 2011
253

mrphoenix80

Member
Jan 1, 2013
251
Here in western NY I find the caliper frames rust under the antirattle clips a good amount. If the pads are stuck in the frame I would(and DO) remove the anti rattle clips and clean the frame down to bare metal and then you can paint the surface to prevent rust again. Reinstall the clips and the pads. If you dont clean them properly you WILL have issues. I also dont grease the exposed sliding surfaces like where the pads touch the frames as grease collects dirt and gums things up more than it helps. I use antisieze on the pins covered by rubber boots to keep out the dirt.

As for the lock tite I normally just reinstall the bolts on the frame to the knuckle with the remaining FACTORY thread locker on them. Never had one sieze or fallout. The caliper to frame bolts normally dont have factory threadlock on them and if they are the slide pins also(like on fullsize trucks) I anti sieze them on the non threaded part.

And I Squeeze the caliper back with either the dual piston tool or a large pair of channel locks and an old brake pad to get both pistons evenly. And after 10+ years in the GM Dealerships and side work have NEVER had an ABS failure caused by this! The thing is that while in the GM/Honda store I found Honda recommends the Brake system flush every 60K and GM does not. The fluid can get nasty so flushing it is a good idea. Also brakefluid is hydroscopic meaning it can absorb moisture from the air. Brake fluid boils at 450F and the water at 212F so if the fluid has moisture in it the mositure boils into steam under heavy braking causing pedal fade. So that is why every thing you read on brakes says use clean fluid from a sealed contianer.
 

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