Changing Brake Pads On M1123

[Hummer Guy]

Im currently on the job of changing the brake pads and notice that the top bolt on the caliper is almost impossible to get without remove the radiator. My rotors are good so Im not worried about them, I just want to change the pads out. Is there any other way to that top bolt without taking the whole radiator and oil coolers off?

 

[frauhansen]

For heaven's sake... you definitely don't need to remove it. In front, it's a gift victory anyway... you changed them both within 1 hour and drank 2 beers on the side!
You can get to the upper screws with the right wrench. If you don't have one, then buy one.

Just likk this but not in metric.



For the rear brakes, reaching the upper bolts is even worse. And as you not only have to push the brake pistons back but also turn them, you need a special tool.
This is either a wrench (cheap) or a press with an integrated wrench (expensive). Either way, you should definitely remove the brake calliper.

Rear Brake Tool - RD4x4

This tool properly rotates and compresses the rear brake caliper piston for rear pad replacement. A must have tool when servicing the rear brakes.

www.rubberduck4x4.com

Economy Rear Brake Tool

Economy rear brake tool. This simple tool makes compressing the rear brake caliper piston simple and easy.

modmafia.com

The manual work involved in resetting and turning the pistons puts so much strain on the fixed brake lines that they have already broken once for a customer. Then the fun really starts as the lines are made of steel and are usually not easy to re-flange.
So it's better to remove them and then change the brake fluid at the same time.

 

[Hummer Guy]

For heaven's sake... you definitely don't need to remove it. In front, it's a gift victory anyway... you changed them both within 1 hour and drank 2 beers on the side!
You can get to the upper screws with the right wrench. If you don't have one, then buy one.

Just likk this but not in metric.
View attachment 914453


For the rear brakes, reaching the upper bolts is even worse. And as you not only have to push the brake pistons back but also turn them, you need a special tool.
This is either a wrench (cheap) or a press with an integrated wrench (expensive). Either way, you should definitely remove the brake calliper.

Rear Brake Tool - RD4x4

This tool properly rotates and compresses the rear brake caliper piston for rear pad replacement. A must have tool when servicing the rear brakes.

www.rubberduck4x4.com

Economy Rear Brake Tool

Economy rear brake tool. This simple tool makes compressing the rear brake caliper piston simple and easy.

modmafia.com

The manual work involved in resetting and turning the pistons puts so much strain on the fixed brake lines that they have already broken once for a customer. Then the fun really starts as the lines are made of steel and are usually not easy to re-flange.
So it's better to remove them and then change the brake fluid at the same time.

Seems like I got lucky since my rear pads seems to be good. Is this the correct wrench Sunex 994002 7/16-Inch x 1/2-Inch S-Style Box Wrench - Box End Wrenches - Amazon.com ?

 

[mgFray]

This is what I used on my M998.

Brake Pad Replacement Tool Set

All the “special” tools required to change the Hummer brake pads. Contents: Front Caliper Compressor Rear Caliper Compressor with Adapter “T” Handle Ratchet Wrench Caliper Guide Pin Lube Plastic scraper…

modmafia.com

The main reason I'm posting this is the T-handle wrench. It makes getting to the top bolt, loosening and tightening it a breeze.. (It was a snapon part in the kit I bought.)

(Note I didn't pay $252 for all of those parts, closer to about $150 and the most expensive bit was the T-handle wrench.)

 

[Mogman]

The snap-on tool they sell for that job is 9/16 as linked above so that 1/2" X 7/16" might not work
I am a little confused as the bolts that hold the calipers on my M998s are allen head.

 

[Mogman]

There is a REAL danger in using a tool like this.
You can put it on a bolt, then back it out to a point that you cannot get the bolt out OR remove the wrench because it gets jammed into something and because it is not reversible you have just seriously painted yourself in a corner, you are now totally screwed as in time to get a torch.
I have no idea if that could be the case in this application I am just saying any time you pick up a ratcheting wrench that is not reversible just be very careful and pay attention!!

 

[mgFray]

The snap-on tool they sell for that job is 9/16 as linked above so that 1/2" X 7/16" might not work
I am a little confused as the bolts that hold the calipers on my M998s are allen head.

No allen head on any of my calipers on my M998.. Everything was standard hex. M1123 and other newer units might be different.

 

[mgFray]

There is a REAL danger in using a tool like this.
You can put it on a bolt, then back it out to a point that you cannot get the bolt out OR remove the wrench because it gets jammed into something and because it is not reversible you have just seriously painted yourself in a corner, you are now totally screwed as in time to get a torch.
I have no idea if that could be the case in this application I am just saying any time you pick up a ratcheting wrench that is not reversible just be very careful and pay attention!!
View attachment 914472

Ya, I always use these one way wrenches for getting the bolt loose or the (near) final tighten, but you definitely have to make sure you don't work yourself into a corner. With that said, I didn't have any issues when I did my brakes with it.

 

[frauhansen]

with the right bent wrench, I think it's 9/16, you don't need this fancy wrench. But I have to admit, I always do this kind of work on the lift.
To make sure that one of only two screws holding my brake in secure, I prefer to have a classic wrench in my hand.
But I may be oldschool or too European. It would never occur to me to work on the vehicle with an electric wrench, except on the wheel bolts.

 

[mgFray]

with the right bent wrench, I think it's 9/16, you don't need this fancy wrench. But I have to admit, I always do this kind of work on the lift.
To make sure that one of only two screws holding my brake is secure, I prefer to have a classic wrench in my hand.
But I may be oldschool or too European. It would never occur to me to work on the vehicle with an electric wrench, except on the wheel bolts.

It's not electric, the t-handle is just a ratcheting (one direction) wrench. The nice bit with the t-handle you can pull it down with a reasonable mount of force/body weight while under the vehicle to get the bolts loose.

Think of it as a ratcheting closed wrench cut to be about 1/4 to 1/2 the norm length with a swivel attached there and a handle at the end of a good 12" bar.

 

[frauhansen]

I know it's not electric. You can see it from the ship.
Perhaps I expressed myself incorrectly in the second part.
The small lever alone is only useful for inserting the screw. You should tighten it to torque with a proper wrench.

 

[Hummer Guy]

The weather finally gave me a good chance to go back and finish this. I got the passenger side pads but my angle wrench ain't long enough for the driver side. I have a question for this one, how do you even move the Caliper on this one? The caliper is almost right on the winch bumper, do you guys remove that whole front bumper off?

 

[Retiredwarhorses]

The weather finally gave me a good chance to go back and finish this. I got the passenger side pads but my angle wrench ain't long enough for the driver side. I have a question for this one, how do you even move the Caliper on this one? The caliper is almost right on the winch bumper, do you guys remove that whole front bumper off?

drop the halfshaft, remove the rotor

 

[Hummer Guy]

drop the halfshaft, remove the rotor

So, I got the bolt off by removing the radiator, but I'm now having issues with removing the caliper since its wedged in the frame. Should I just take off the frame piece above the caliper or remove the half shaft? The frame piece above it seems like it just has 4 bolts holding it, but I don't want to run across one of those "Got you moments" where its more to it than that to remove that piece.

 

[Retiredwarhorses]

So, I got the bolt off by removing the radiator, but I'm now having issues with removing the caliper since its wedged in the frame. Should I just take off the frame piece above the caliper or remove the half shaft? The frame piece above it seems like it just has 4 bolts holding it, but I don't want to run across one of those "Got you moments" where its more to it than that to remove that piece.

you have gone waaaay down a rabbit hole….

 

[Hummer Guy]

you have gone waaaay down a rabbit hole….

Yes but had the plans to remove it anyways to change the quick disconnect hose going to the fan clutch. I think it has a slow leak

 

[Retiredwarhorses]

Yes but had the plans to remove it anyways to change the quick disconnect hose going to the fan clutch. I think it has a slow leak

You don’t need to remove the radiator to replace that either

 

[Hummer Guy]

drop the halfshaft, remove the rotor

I drop the half shaft but my rotor and caliper is wedged between the frame, anything I'm missing in removing it?

 

[mgFray]

Do you have a picture? I know some models have a bracket that sits below the rotors that need to be removed... but I can't think of anything else.

 

[Hummer Guy]

Do you have a picture? I know some models have a bracket that sits below the rotors that need to be removed... but I can't think of anything else.

I ended up just fighting with it and got the rotor removed and new pads on. Do you guys use locktite on the half shaft bolts or just let it go with the lock washers?

I know shitty pictures but my good flashlight had died.