Help With Brakes

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Help With Brakes

Post by johncarrol » Tue Mar 13, 2018 6:07 pm

I've owned my 2005 M1123 since July 2017 and put around 1,500 miles a month on it carrying no cargo as a daily driver. I travel over a small ridge almost every day, and I'd say I use my brakes more than normal, but I wouldn't say I abuse them comparing it to previous 4x4 trucks I drove the same places and way with no brake issues. My GVWR is 10,300lbs and I have the 12 inch vented rotors. The first day I owned it, I looked at the pad thickness and rotor surface which both looked new. After a few weeks of driving it, I noticed when using moderate brake pressure, it felt like I was driving over a washboard that got so bad, after about 2 months it was vibrating the body so bad I thought the calipers and rotors were going to fall off. I removed, chamfered, and deglazed all the pads. I checked the rotor bolts and flange nuts which all were tight. I deglazed all the rotor surfaces which didn't look too different from normal. I polished and used antisieze on all the caliper slide pins which had all the bushings and thin sleeves in place. All that had a positive result for about a week, then got bad again like the way it was before. I then, had a friend with a brake machine cut all 4 rotors while I was present to see if there was anything out of the ordinary. That fixed the problem for about 2-3 weeks, then slowly back to the washboard. A couple days before writing this post, I checked and noticed hard spots on 3 rotors spaced somewhat evenly around the center of the pad surface and the pads look like they will be shot in about 2-3 months. What I don't want to do is spend money and end up with new rotors and pads that are no better than I have now. I would like to go with slotted, cross drilled rotors and noticed many of them being offered with pads on eBay cheap for H1s. The only thing I can find for a 12inch vented rotor HMMWV is expensive and looks no better than what I have. All the photos on eBay of H1 rotors and pads look different. I'm not familiar with H1s. I thought they used the same rotors and pads. If anyone can help me with choosing good replacement rotors and pads, it would be greatly appreciated.

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Re: Help With Brakes

Post by Action » Tue Mar 13, 2018 6:17 pm

Where did the 12" rotor you have on it come from? I thought the 10k trucks came with 10" rotors? Do you have 12k pads in there?

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Re: Help With Brakes

Post by johncarrol » Tue Mar 13, 2018 6:31 pm

That's confusing to me. Maybe 10K doesn't necessarily mean equipped with 10 inch rotors. The OD of my rotors are 12 inches, and by looking at a photo from another post, my pads look like the ones for 12 inch rotors.

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Re: Help With Brakes

Post by 86humv » Tue Mar 13, 2018 7:51 pm

Those trucks come with 12k X members and brakes.
They would have the rotor protection tubes between X members.
The H1's had 10k brakes, unless it was an Alpha 2005-2006
You could put 10k rotors and pads on.
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Re: Help With Brakes

Post by dilvoy » Tue Mar 13, 2018 8:09 pm

Action wrote:
Tue Mar 13, 2018 6:17 pm
Where did the 12" rotor you have on it come from? I thought the 10k trucks came with 10" rotors? Do you have 12k pads in there?

Jason

The A2 Humvees are rated at 10.3k, but have the 12" brake rotors and 12K Half Shafts like a Commercial 12K Hummers would have and I guess what the early ECV Humvees would have had too, I guess. I bet there are exceptions though, but what is being sold through GP is 10.3 rated A2 models with the large half shaft and 12" vented rotors with the skid tubes for the rotors like Gred said. I think a call to David at Hummerpartsguy.com would get the right parts the first time.
Last edited by dilvoy on Tue Mar 13, 2018 8:13 pm, edited 1 time in total.
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Re: Help With Brakes

Post by 86humv » Tue Mar 13, 2018 8:12 pm

I have 12k rotors and pad...nos available
And nos calipers.
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Re: Help With Brakes

Post by johncarrol » Wed Mar 14, 2018 5:58 am

Thanks guys for the info. And thanks for the offer of the nos stuff, but there's no way of telling if the replacement nos rotors may or may not be from bad castings until it's too late like I believe mine were. I used to machine castings for a living, and hard spots from impurities sometimes cannot be detected initially. I would rather take my chances on replacing them with 10 inch cross drilled/slotted H1 rotors and pads if my existing calipers will work. Can someone verify for me again if I purchased 4 rotors and pads for an H1 (not Alpha), the rotors will fit my flanges and the pads will fit my calipers. Thanks again,

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Re: Help With Brakes

Post by 86humv » Wed Mar 14, 2018 8:15 am

johncarrol wrote:
Wed Mar 14, 2018 5:58 am
Thanks guys for the info. And thanks for the offer of the nos stuff, but there's no way of telling if the replacement nos rotors may or may not be from bad castings until it's too late like I believe mine were. I used to machine castings for a living, and hard spots from impurities sometimes cannot be detected initially. I would rather take my chances on replacing them with 10 inch cross drilled/slotted H1 rotors and pads if my existing calipers will work. Can someone verify for me again if I purchased 4 rotors and pads for an H1 (not Alpha), the rotors will fit my flanges and the pads will fit my calipers. Thanks again,
They should fit.
The cross drilled are not OEM, so the odds are they are chinese..
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Re: Help With Brakes

Post by Retired War Horses » Wed Mar 14, 2018 9:19 am

You don’t have many options other then OEM....sounds like you have warped rotors. Put in NOS 12in vented rotors and the correct pads for the vented 12in rotor. Always replace in pairs...so that means either all fronts or all rears, not just a side.
Just takes one warped rotor to make the truck shudder...warpage is caused by riding the brakes on long down hills and overheating them, also sticky guide pins and this hangs up the caliper. I recommend anyone buying these trucks, especially the marine corp trucks to check there calipers and that they are still floating correctly, these truck have had a hard life near saltwater, the caliper should be a bit sloppy, pads should rise and fall easily, or at minimum move under no pressure.
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Re: Help With Brakes

Post by johncarrol » Wed Mar 14, 2018 9:44 am

I thought of this after my last post. If I go from 12 to 10 inch rotors, do I need to also change the brackets that the slide pins screw into, so my calipers will sit lower over the 2 inch smaller OD rotors?

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Re: Help With Brakes

Post by Retired War Horses » Wed Mar 14, 2018 9:51 am

You don’t want I go backwards...and yes, you will need to change out the caliper brackets on the diffs.
Stick with what it was designed for...
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Re: Help With Brakes

Post by johncarrol » Wed Mar 14, 2018 11:18 am

With all due respect and thank you for your service to this great country, I believe my M1123 came to me with the rotors that it was designed for that were recently replaced before I took possession of it. I believe those rotors are defective and do not want to risk replacing them with ones that could possibly have the same problem. They are not warped, but have impurities in them which make hard spots in them that make the pads shudder when applied. My experience with warped rotors gives a pulsing effect felt in the brake pedal when applied. Why shouldn't I try 10 inch rotors that are cross drilled and slotted. Proven to be better tech., that are a fraction of the cost with pads included, that are designed as a replacement for an H1 (not Alpha) that is much heavier going down the road than my HMMWV will ever be. And also will be much easier to replace the pads on vs the 12 inch ones in the future. I am so glad this problem is unique to me and is not a common problem.

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Re: Help With Brakes

Post by dilvoy » Wed Mar 14, 2018 11:29 am

You can go to the smaller 10" brake rotors. You need to change the Adaptors and the rest of your parts will work, except you need to get the brake pads for the 10,300 trucks. The bolts that hold the adaptors need to have locktite on them when you install them so they don't come loose. Driver's front Adaptor is unique, the other three are the same as each other. Lots of cheap rotors available for the 10.3 size. Here is a photo of a 12K Adaptor.
Image
Last edited by dilvoy on Wed Mar 14, 2018 12:25 pm, edited 1 time in total.
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Re: Help With Brakes

Post by artificer » Wed Mar 14, 2018 12:04 pm

Suggest the problem may be other than the rotors & pads, but that they are the result.
Solve the primary issue first, as replacing parts won't fix things, just like it didn't previously. Anti-lock system?

As for hard spots they occur because the brakes are held on when the brake rotors & pads are very hot....e.g. @ traffic lights after hard braking.
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Re: Help With Brakes

Post by johncarrol » Wed Mar 14, 2018 1:04 pm

Thanks so much dilvoy. I'm looking at a set: eBay 4 rotors with ceramic pads 1992-1995 H1 and 1996-2004 10,000GVW H1 with a 1 year warranty for $105.95 That's crazy. That's not the first $105.95 or more I'm willing to take the chance on vs. 4 new AMG 12 inch rotors w/pads. Can you or anyone tell me the part#s of the adapters I'll need, or does anyone have any lying around they want to sell?

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