2nd Gen Non-Engine/Transmission Front disc rotors keep cracking

[Bseg]

I replaced my original front rotors at about 70k miles cause they had some bad cracks from over heating. I had talked to Sam Peterson, he's a great guy, real helpful and bought a set of stock rotors and some pads from him.



After about 25k miles I see these rotors are starting to develop the same small cracks.



Is this cracking normal?



I considered drilled rotors but some people say they won't help that much.



Only other suggestion so far is to put in the 1 ton rear cylinders to prevent from the fronts doing so much work.

 

[diesel DOG]

I am pretty rough on brakes 23 front and 27 on rears when replaced. I did the brake job but was amazed that the rotor was not worn just the pads. I put the same stock pads back it. Drilling won't help and may make them crack just from my race car experience. What type of pads did you get? Some may produce more heat than others.

 

[Bseg]

The pads I have now were purchased from Sam P. but I'm not sure what the composition of them is.



I had Raybestos before and had the same problem. In fact my front brakes got so hot one time that the fluid boiled in the caliper and the rotor was smoking.



I realize that the front brakes do the majority of the work and I have an auto trans too which doesn't aid in slowing down.



I'm just not sure if these cracks are something to worry about or if they are normal.

 

[diesel DOG]

I tow sometimes and have auto and as you see 23 isn't much on pads. Small crazing cracks or OK like on my track car but the rotor can change to a big crack Cracks are from heat. The stock pads were exspensive but the way they treated the rotors I figure it was worth it. Sure they are not dragging? Are both the same?

 

[illflem]

Easy way to crack/warp rotors is to hold your truck in one spot after an extended period of braking such as coming down an offramp slowing from highway speed then getting stuck at a red light. The pads against the rotors don't allow the rotors to cool evenly causing stress. Keep your foot off the brake or use your parking brake if that's what it takes. If you have an auto put it in N.

 

[Bseg]

Thanks Diesel DOG and Illflem for the suggestions.



Regarding the stock pads I had the same type of problem using them too. I made sure to grease the slide bolts so that the pads wouldn't drag on the rotor so I don't think that's the problem. It's probably mainly due to driving in stop and go traffic to and from work.



I know they get real hot from the on and off braking.



The cracks are real fine, you can barely feel them with a finger nail. I just don't recall ever seeing them on any other disc rotors on other vechicles. I can probably turn them and they will be gone.

 

[BStacy]

1 Ton Rear Brake Cylinders

How much work is involved in changing from the 2500 rear brake cylinders to the 3500 rear brake cylinders? Does it require a backing plate change or does it all bolt up?

 

[Joe G.]

The 3500 rear brake cylinders bolt right up. You should check the part numbers to see if your truck has the same size cylinders as the 3500 already. I don't know what year the 2500 changed to the big cylinders.

 

[jtwcummins]

The statement you made about how hot the pads and rotors get makes me think your calipers are shot. They might be dragging. I had the best results using EGR front brakes. Kinda expensive, but I don't have brake issues at all. They blue print the calipers and use silicon seals, better perfomance in heat.

 

[BWilson]

I don't know what the rears looked like when you changed them, but on my truck they just don't automatically adjust well so every 5000 miles or so I climb under it and give the adjusters a few cranks.



Oh yeah, the exhaust brake REALLY extended my brake life and I drive mostly unloaded in stop and go traffic.

 

[Bseg]

Well, unfortunately the reason I started this thread was because I heard a strange sound coming from my front brakes yesterday morning when I arrived at work. Sounded like a rotor on a brake lathe.



Turns out that the inboard pad disappeared from the backing plate and my rotor is now trashed.



All I can figure is that the pad tore off sometime on the way to work. I put some new pads on but will have to decide what to do about the rotors.



Do the 1 ton wheel cylinders help that much?



I have adjusted my rear shoes but they still don't seem to be doing anything to stop the truck.



Thanks everyone for your help.

 

[Mundgyver]

The pad tearing away from the backing plate is not that uncommon. I have a friend that has had this happen to him on his truck. Both front rotors were trashed hard.



I think it has to do with the way people brake. Not say this is the case here, its just an observaton. My friends wife drives his truck allot. She generally drive fairly quick and waits till the last second to put on the brakes, and then she is braking hard. They have a 2001 LB automatic with about 60,000 to 63,000 turns on it and have been through 3 sets of brakes and 2 sets of rotors.



I've got 106,000 turns on my 2001 and am still on my original factory brakes and rotors with about 50 percent of my pads left. Course mine is a 6 speed and I do have an exhaust brake, but I generally go light with my touch to the brakes and give myself distance for slowing.

 

[Bseg]

I agree with the braking easy, I try and slow down gently so I don't end up heating the brakes and causing them to wear.



I did call Sam and he was real helpful, he said the pad shouldn't have come off and he will get me a replacement set of pads. He gave me a good suggestion regarding whether or not they are heating up, what I need to do is run the truck up and down a few hills etc. to get the brakes hot and then use one of those infra red temp sensors (air conditioning people use them) and measure the temp of both rotors, they should be about 250 degrees or less but can take up to about 300 degrees if you run them real hard. Main thing is both sides should be within about 10 degrees of each other.



Regarding the cracking he said that if the cracks are very fine and consistent throughout the rotor they could be somewhat normal.



I am going to re-visit the rear brakes and make sure that they are doing their job and then I have to track down the temp tool.



He also gave me the Wagner part # for the 1 ton rear cylinders, F79767. They are a 1 1/16" cylinder and bolt right in.



Last of all I guess the standard trans and an exhaust brake would extend the life of the pads. Maybe if I ever get rich I can buy another truck!

 

[Jff24Gordn]

I lost a break pad a few years ago. All of a sudden, I had no breaks. I limped it the rest of the way home, rural area in the middle of the night. As i drive home, the adjuster made up for it and it drove better, but it was not a good feeling that first time they didnt work.

 

[willyslover]

rear adjustments are important, are rears glazred / oil soaked ? rear seal weeping ?... axel bearing shot allowing drum to move around ?

 

[dresslered]

I think that if 'Bad Brad' had made it to the meeting last night, he might have even had some personal attention. Good to see you again Gary.

 

[Bseg]

If Bad Brad had brakes he would have shown up.



Gary, last time I checked the rears they were fine and I even adjusted them. I will check them again in the next few days and will definitely tighten them up. They don't grab as well as they could cause even on the driveway the emergency brake doesn't always keep the truck from rolling back unless it's fully depressed.

 

[BWilson]

The emergency brake not working well is my indicator I use to know when to tighten up the rear adjusters. Most of time I just give each side a few clicks if it's not too bad; however, the right way to do it is to jack up the rear end, with the truck in neutral and keep tightening until the the brakes just begin to grab. You will know this by turning the wheel as you tighten the adjuster.



If you do happen to pull the rear drums, Illflems trick of jacking the truck up, taking off the rear wheels, putting some lug nuts back on each side, then run the truck 10-15 mph and hit the brakes. They pop right off. Just don't forget to put the lug nuts back on before trying this because they will launch the drums right off of the truck.

 

[Bseg]

I have used Illflems method to remove the drums, it works great. The first time I tried to remove them I couldn't get them off and thought there must be a special tool or something to get them off.

 

[daveshoe]

Illflem method-- stupid question

Does this method work on all brands of trucks? Reason I ask is a guy at a respected shop used a air hammer for 2 hours on my Chev before he got out an 8 pound sledge. After watching this, I decided to do my own work if possible. I used a Hilti demo hammer with good results. It seems to help the penetrating oil to do it's thing much quicker. Oh yea , and why in heck these pros do not use never seize for the next time mystifies me.