Front brake rotor tapped removal holes bolt size?

[Outdoors_Guy_88]

I have front brake rotors up here in the Northern US corrosion belt and they are seized on really well.

 

Normally I use the trick of installing bolts in the 2 tapped rotor holes to pop the rotor loose from the hub.

 

Anyone know the size bolts I need to fit the tapped holes in the factory brake rotor?

 

[Raleighkozey]

I am very interested in your problems, I will do more research to find the fastest answer for you.

 wordle hint

[swathdiver]

On my 2009-2013 trucks it is an M8 x 1.25 x 30

 

Hillman 44538

Crown Bolt 15888

Everbilt 844118

GM 11609271

[Outdoors_Guy_88]

2 hours ago, swathdiver said:

On my 2009-2013 trucks it is an M8 x 1.25 x 30

 

Hillman 44538

Crown Bolt 15888

Everbilt 844118

GM 11609271

Thanks for the information, but that's not what I was looking for.  That is the rotor retention bolt.

 

There are additional tapped holes in the factory rotors for forcing the rotor from the hub.  These are what I am interested in.

[mikeyk101]

A more simple way to try would be this. I'm assuming you are replacing the rotors. Although this isn't a Silverado/Sierra, the technique should work the same.

 

 

 

Another idea to try is after removing the caliper mounting bracket, put those bolts back into the holes and evenly tighten both and this may make the rotor pop free. 

 

Then before mounting new rotors, make sure to use wire brush to clean up the rust off the hub and spread on some high temp grease so this doesn't happen next time.

Edited January 17, 2023 by mikeyk101

[Salsa De Piña]

The caliper bolts should be the right size.  That's what I've used in the past.

Edited January 17, 2023 by Salsa De Piña

[swathdiver]

8 hours ago, Outdoors_Guy_88 said:

Thanks for the information, but that's not what I was looking for.  That is the rotor retention bolt.

 

There are additional tapped holes in the factory rotors for forcing the rotor from the hub.  These are what I am interested in.

 

Well, on mine (GMT900) they are one and the same.

[Outdoors_Guy_88]

6 hours ago, mikeyk101 said:

Another idea to try is after removing the caliper mounting bracket, put those bolts back into the holes and evenly tighten both and this may make the rotor pop free. 

 

Then before mounting new rotors, make sure to use wire brush to clean up the rust off the hub and spread on some high temp grease so this doesn't happen next time.

I have tried hammering around the rotor, hitting on the front side and back side, and vibrating around the lug bolts with an air hammer.  These rotors are stuck on good.

 

I'll have to try the bracket bolts (or even longer bolts) and push from the back side, but I am worried about the strength of those "ears" that hold the bracket on.

 

Yes, I'll be sure to clean up the hubs and put high-temp, anti-seize grease on them before the new rotors.

[Outdoors_Guy_88]

6 hours ago, Salsa De Piña said:

The caliper bolts should be the right size.  That's what I've used in the past.

The caliper bolts fit on the rear rotors, but too big diameter for the 2 tapped removal holes front rotors.  I just tried a M10x1.5 bolt and it only goes about two turns, so almost, but not quite correct size.

[mikeyk101]

Did you try spraying some decent penetrating oil around the lugs and exposed part of hub? Maybe also on back side of rotor where it mates to hub if you can get it in there. Maybe try that and let it sit overnight.

[richard wysong]

Heat it up

[Outdoors_Guy_88]

8 hours ago, richard wysong said:

Heat it up

Yep!  That's next.

[richard wysong]

Swathdiver is correct . they are 8x1.25 but you may have something different, if a 10x150 doesn't work try a 3/8 or a 10 x1.25

[16LT4]

Put the caliper and wheel back on, install the lug nuts until  they contact the wheel, then back them off 0.5-1 turn.  Hop in the truck, put in gear, roll a few feet forward, and stab the brakes.  Repeat in reverse.  Jack up, remove wheel, remove caliper/bracket, and catch rotor as it falls off.  As strong as one may be, a 6000 lb. Silverado is stronger.

 

The same process is used to free aluminum wheels that have galvanically attached themselves to steel hubs, and works every time.  I do something similar to free driveshafts that have frozen in place on pinion yokes.

Edited January 19, 2023 by 16LT4

[midwestdenaliguy]

On 1/15/2023 at 4:26 PM, Outdoors_Guy_88 said:

I have front brake rotors up here in the Northern US corrosion belt and they are seized on really well.

 

Normally I use the trick of installing bolts in the 2 tapped rotor holes to pop the rotor loose from the hub.

 

Anyone know the size bolts I need to fit the tapped holes in the factory brake rotor?

 

 

Can't help you with the bolt size, just want to wish you luck. Man I do not miss living in Michigan for this reason. Spent more time fighting seized parts and bolts than I'd like to admit. Haven't used a torch once since moving to Missouri.