M1123 brakes

[FMFHMMWV]

Does anyone have any idea on how to disassemble the brakes without taking the caliper off. My goal is to just swap out pads. The rears look easy (there's a lot of room). The fronts are tight in there especially the driver side.

 

[Coug]

Does anyone have any idea on how to disassemble the brakes without taking the caliper off. My goal is to just swap out pads. The rears look easy (there's a lot of room). The fronts are tight in there especially the driver side.

In the manual it specifically states that on the left side to remove the brake pads the halfshaft must be removed.

 

[jake20]

Does anyone have any idea on how to disassemble the brakes without taking the caliper off. My goal is to just swap out pads. The rears look easy (there's a lot of room). The fronts are tight in there especially the driver side.

The rears are easier to get to but you need a special tool to retract the pistons. Only other way is to remove the calipers completely and retract them with channel locks in a vise.

Don’t take the rear apart until you’ve got a plan to retract the pistons. Here’s the tool I used

Rear Brake Caliper Compression Tool

Essential tool for changing rear brake pads. The rear brake on the Hummer / H1 must be alternately turned and compressed to release the parking brake and collapse the piston.…

modmafia.com

I don’t recall if I was able to do the fronts without dropping the half shafts, though it’s not that hard and nord lock washers are cheap from HPG.

 

[87cr250r]

Don't use lock washers if you don't need them. They provide a moisture path to the threads of the bolts and cause seized fasteners. Locking compounds work better if you think they need them. Wedge lock type washers are for high temperature where compounds don't work.

 

[jake20]

Don't use lock washers if you don't need them. They provide a moisture path to the threads of the bolts and cause seized fasteners. Locking compounds work better if you think they need them. Wedge lock type washers are for high temperature where compounds don't work.

That’s an interesting point, so you’d suggest using red or blue loctite on the halfshafts instead?

 

[Coug]

That’s an interesting point, so you’d suggest using red or blue loctite on the halfshafts instead?

halfshaft bolts are also open on the backside, so using split lock washers doesn't change anything there. You should use both locking washers (whether the split ring type or nordlock) as well as threadlocker, or use the locking bolt kit (it's kind of spendy though, so unless you foresee yourself removing the halfshaft at least a half dozen or more times then cheaper/easier to just keep replacement bolts on hand (and yes, the bolts should be replaced every time if possible, as the torque spec in the manual is in excess of the standard torque rating for that size/grade of bolt.)

You are supposed to use sealing compound on the caliper bolts
full description of the thread sealing as found in appendix C item 45:
SEALING COMPOUND: thread-locking, high strength (80244) MIL-S-46163, type I, grade K
Which is just the military specification for Loctite 271, red high strength type.

 

[juanprado]

I would not use red on caliper bolts as you might have a rough time if you need to go in there again.
Maybe blue or yellow ...
But I don't use any on caliper bolts. Civy caliper bolts don't need them. Civy calipers don't fall off....
Ymmv

 

[Mogman]

The TM calls for red, I use red and Nordlock, it does take allot of torque to remove but that has never been a problem, mostly it is just the head locked with the washers.
I too use new bolts every time, I have now gone to flanged bolts and the larger dia. Nordlocks just for a little extra grip, just cuz....
TM calls for Blue on the 3/8' end bolt, I also use Nordlocks there, stainless ones so I do not have to worry about the galv. flaking off, you do want to be careful when removing the end bolt top make sure the washer or washers in the case of Nordlocks come out with the bolt.
I beat the heck out of my half shafts and never had an issue with them coming loose, slinging all the boots off is another story, in fact I am about to go out and abuse them some more today, the perks of being retired...

 

[FMFHMMWV]

Thanks for the update on threadless and washers.
- I got the caliper off and the old pads out.
- I c-clamped the caliper to push the piston in.
- I put the new pads in
The caliper doesn't want to squeeze around the new pads even with piston all the way in.

 

[papakb]

Make sure you put some lube on the back side (steel) of the pads or they'll squeal on you when you step on the brakes. I personally have always used Lubriplate white lithium grease but there are plenty of brands to chose from.

BTW, the allen head in the caliper slide screws is a 7mm. Not a size commonly found in wrench sets.

 

[juanprado]

Take master cyl cap off to make sure you can retract the piston fully by trying c clamp again with system open.

The caliper moves back and forth on the pins. Use brake silicone grease to make sure caliper can slide easily.

 

[Coug]

if it's all the way compressed and won't fit, then it's possible you have the wrong brake pads.
There are multiple different 12k brake pads, and the ones for solid rotors are too thick to work with the vented rotors.

EDIT: you wouldn't be the first one to order the wrong pads; I've seen several other posts/threads in the past where that ended up being the issue.

 

[jake20]

I would not use red on caliper bolts as you might have a rough time if you need to go in there again.
Maybe blue or yellow ...
But I don't use any on caliper bolts. Civy caliper bolts don't need them. Civy calipers don't fall off....
Ymmv

The front top caliper bolts especially, those are very tight to squeeze a wrench into. I put blue on them and haven’t had issues yet.

Where I have had issues is the actual entire assembly coming loose from the differential. I used red on those, whatever maintenance shop took them apart before me didn’t do it right.

 

[Coug]

The front top caliper bolts especially, those are very tight to squeeze a wrench into. I put blue on them and haven’t had issues yet.

Where I have had issues is the actual entire assembly coming loose from the differential. I used red on those, whatever maintenance shop took them apart before me didn’t do it right.

I've had that happen on 3 of my 4 caliper brackets so far. I used both loctite and nordlock washers on them to prevent another occurrence. First time the caliper bracket came loose I was 100 miles from home and 9pm during covid when every store was shutting down for the night. Got to wallyworld before they closed and used some long needle nose I bought there to thread them in enough that they no longer hit the halfshaft bolt ends

 

[jake20]

I've had that happen on 3 of my 4 caliper brackets so far. I used both loctite and nordlock washers on them to prevent another occurrence. First time the caliper bracket came loose I was 100 miles from home and 9pm during covid when every store was shutting down for the night. Got to wallyworld before they closed and used some long needle nose I bought there to thread them in enough that they no longer hit the halfshaft bolt ends

Yea I first noticed when I crawled under my truck to inspect it, I like to randomly try and move/shake things and I noticed that both my fronts were sliding around on the diff.

Sounds like your situation was a little more dire though if they were whacking the halfshaft bolts. Definitely not fun having an issue away from home base lol

I’ve been thinking of making a permanent tool kit to keep in the truck for situations like this.

 

[FMFHMMWV]

Thanks everyone got her buttoned up tight with nordlocks and red thread locker. Word to the wise...wear a respirator and eye protection. I got covered in brake dust and all I was wearing were some shorts

 

[FMFHMMWV]

So update:

1. Made my own brake tool.

2. Had some custom steel braided lines installed to get rid of the crappy hard lines and multiple fitting/failure points

 

[Mogman]

So update:

1. Made my own brake tool.

2. Had some custom steel braided lines installed to get rid of the crappy hard lines and multiple fitting/failure points

Tell us where you got the brake lines..

 

[jake20]

Tell us where you got the brake lines..

lol I too have the same inquiry

Pics? Worth a thousand words

 

[FMFHMMWV]

Old hmmwv line problems...https://youtu.be/5B_qlqO0dvM