Warped Rotors, ABS or Master Cylinder?

Dillyo82

Original poster
Member
Aug 17, 2012
80
I have noticed a pulsation while braking. I can't say it's constant either. I replaced my Front rotors, Turned the Rear and replaced with Ceramic Pads. Seemed to be eliminated, until about a year later. I also Flushed/replaced the Brake fluid. Could the rotors be Warped again? I make sure to torque them down correctly when I rotate as I have read this can cause Warpage. I did just get new tires a couple months ago. I assume they torqued the nuts correctly, but as they say..."If you want something done right, do it yourself" Could this be the Master Cylinder or ABS system or just another Warped issue?
The only other thing I'm thinking is the Master Cylinder "Test" in my Haynes Manual (Holding Brake while Starting up).
 

Hatchet

Member
Nov 21, 2011
2,405
You said it isn't constant. Does it pulse slower and lower speeds and faster at higher speeds?

My last pulsating was depending on the speed of the vehicle. So I replaced all 4 rotors and it disappeared.
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
Hatchet said:
You said it isn't constant. Does it pulse slower and lower speeds and faster at higher speeds?

My last pulsating was depending on the speed of the vehicle. So I replaced all 4 rotors and it disappeared.

Yes it's like the rotors are warped again, but I don't notice it all the time. You would think they would do it all the time if this were the case.
I replaced the Front Rotors and Turned the Rear a little over a year ago and it seemed to be solved until recently. I'll be really pissed if I have to do this again!:hissyfit::mad:
FYI: I only drive about 12k mi a year...95% Highway.
 

Hatchet

Member
Nov 21, 2011
2,405
Yea mine were constant and ended up being my front ones. Does seem odd to be doing them again. If you have a magnetic dial meter like this one.

View attachment 22656

Then you can test it your self.
 

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Dillyo82

Original poster
Member
Aug 17, 2012
80
I'll have to buy one...A guy can never have enough tools!
Why magnetic?
 

Hatchet

Member
Nov 21, 2011
2,405
Doesnt have to be. I have used them before and those where easier to use then trying to clamp it or have it sitting on a table and hope it dont move. Just mag it to the body/frame/anything steel that doesnt move. And set the dial on the rotor and spin...
 

6716

Member
Jul 24, 2012
822
Dillyo82 said:
I have noticed a pulsation while braking. I can't say it's constant either. I replaced my Front rotors, Turned the Rear and replaced with Ceramic Pads. Seemed to be eliminated, until about a year later. I also Flushed/replaced the Brake fluid. Could the rotors be Warped again? I make sure to torque them down correctly when I rotate as I have read this can cause Warpage. I did just get new tires a couple months ago. I assume they torqued the nuts correctly, but as they say..."If you want something done right, do it yourself" Could this be the Master Cylinder or ABS system or just another Warped issue?
The only other thing I'm thinking is the Master Cylinder "Test" in my Haynes Manual (Holding Brake while Starting up).

I had pretty significant pulsating that got worse as the pads and rotors got older, but I was pig headed about getting my money's worth and rode it out until the wear indicators on the pads started to screech.

One thing I read that seemed to square with my experience was that in some cases, like stopping hard and fast while towing a heavy trailer that doesn't have its own brakes, the pads can make an imprint or leave some residue on the rotor because it got so hot on a fast, complete stop with a long compression once stopped. I don't know if that's true, but it made sense in my situation.

This situation was likely the source of my pulsating. When I had the vehicle in for another problem I had them check the rotors, and they came back "unwarped".

Complete new pads & rotors got rid of the problem for me.

Do you tow?

Willing to try completely new rotors on the back?
 

Jkust

Member
Dec 4, 2011
946
I'm wondering why you would resurface rotors? Even non-Chinese, upper end rotors are inexpensive. I think my rears were $60 if I recall and they were one notch under slotted which I didn't want. Look for a wholesale to public brake equipment sales place where everything is a lot less than a parts store or shop.
 

6716

Member
Jul 24, 2012
822
Jkust said:
I'm wondering why you would resurface rotors? Even non-Chinese, upper end rotors are inexpensive. I think my rears were $60 if I recall and they were one notch under slotted which I didn't want. Look for a wholesale to public brake equipment sales place where everything is a lot less than a parts store or shop.

:iagree:

rockauto.com takes a few days, but the pricing is pretty good.
 

Jkust

Member
Dec 4, 2011
946
6716 said:
:iagree:

rockauto.com takes a few days, but the pricing is pretty good.

Retail auto parts stores (don't mean auto shops) can be a good financial investment as their profits are astronomical. You can just feel you are going to get ripped off as soon as you walk in the door. They've been written up in Money type magazines as some of the highest profit businesses.
 

NJTB

Member
Aug 27, 2012
612
Flemington, NJ
FWIW, try sticking to American made rotors. I got pads and rotors from Autozone about 5,000 miles ago and they're starting to warp already. Should have gone to the dealer and got OEM.
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
NJTB said:
FWIW, try sticking to American made rotors. I got pads and rotors from Autozone about 5,000 miles ago and they're starting to warp already. Should have gone to the dealer and got OEM.

Yeah...that's where I got them, Autozone. The fronts were about $50 a piece new and got the Rear Turned for $14 for both...better than $100 right? I thought at the time it was good get the "upgraded" vented DuraLast option (Part Number: 55079) as opposed to the non-vented option. If they end up being warped, I'll be pissed, but stick with USA Parts for now on. I just don't see why they don't pulsate all the time like before.

P.S.
I saw this in the description and went for it...
  • Manufactured in TS16949 certified facilities
  • Engineered to reduce brake noise
  • High strength alloy for long life and increased resistance to warping
  • Balanced for smooth stopping
 

SBUBandit

Member
Dec 5, 2011
597
Dillyo82 said:
I did just get new tires a couple months ago. I assume they torqued the nuts correctly

Don't. I've seen idiots at the tire places just put them on with the impact wrench cranked all the way up. Then you need a breaker bar to get them off
 

Hatchet

Member
Nov 21, 2011
2,405
I bought my drilled and slotted front and back for 130. There is a thread about them on here. I'm on my phone so can't search. But they are great. I'll find ya a link in the morning so you can have it just in case
 
Mar 15, 2012
45
I have experienced a come and go with my rotors also. Even if you torqued them correctly, one trip to a shop uising high powered impact wrenches can cause them to go off. I usually retorque my wheels after any shop visit as I usally torque my own wheels too. Even when you are not using the cheapies, the rotors seems sensitive to even minor torque differences. I usually will retorque if they become too jerky when slowing, you may want to retorque and see if that solves your problem.

Just as SBU Bandit stated, I have had to stand on a breaker bar to get them loose before and I am no lightweight, don't ever assume they torqued them right unless you are right there as they do it. Our trucks only need 103 ft/lbs, my kids can do that.
 

NJTB

Member
Aug 27, 2012
612
Flemington, NJ
When installing rotors, check the axle flange they sit on. It has a few holes in it (the axle flange) that, over time, will fill with dirt/rust and make a 'bump'. If you put new rotors on, this 'bump' will make them seem warped. Use a piece of sandpaper to make sure the surface where the rotor sits is flat.
 

Hatchet

Member
Nov 21, 2011
2,405

Jkust

Member
Dec 4, 2011
946
Also, the 'hat' portion of the better rotors won't rust like the cheap Chinese ones will or so that's what I understand. Time will tell on mine but both of my 360's are 07's and actually didn't get purchased until 08 yet one has completely corrotsion free brake parts and the other's parts were all corroded. Assuming they both came off the same assembly line and both came from salty conditions one lived in Michigan and the other in Minnesota, I wonder why the corrosion differences.
 

Hatchet

Member
Nov 21, 2011
2,405

Dillyo82

Original poster
Member
Aug 17, 2012
80
Hatchet said:
Yea that is what i paid. I was wrong in my first post. I corrected tho.

That's a great deal! How long have you had these on? Any noticeable performance gains from OEM? Seems to good to be true for under $40 ea, but if you and others like them, I guess it's better than Paying more at AutoZone for something that has seemed to have failed me already. I'll get them if they are warped.:thumbsup:
 

SBUBandit

Member
Dec 5, 2011
597
Dillyo82 said:
That's a great deal! How long have you had these on? Any noticeable performance gains from OEM? Seems to good to be true for under $40 ea, but if you and others like them, I guess it's better than Paying more at AutoZone for something that has seemed to have failed me already. I'll get them if they are warped.:thumbsup:

I have the Brakemotive's too. Love them. I like the performance and they look great too.
 

Hatchet

Member
Nov 21, 2011
2,405
I haven't had OEM since I bought the truck. And even then it was for a week before i got some drilled and slotted. But these new pairs I got from brakemotive Ive had on for a few months now. They work great so far for me. I have done a few panic stops, and they f***ing stop you.


http://gmtnation.com/f78/brakemotive-drilled-slotted-rotors-pics-2274/

heres the thread. It shows pics of the rotors and what not to so you can see them.
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
Hatchet said:
I haven't had OEM since I bought the truck. And even then it was for a week before i got some drilled and slotted. But these new pairs I got from brakemotive Ive had on for a few months now. They work great so far for me. I have done a few panic stops, and they f***ing stop you.


http://gmtnation.com/f78/brakemotive-drilled-slotted-rotors-pics-2274/

heres the thread. It shows pics of the rotors and what not to so you can see them.

Look great....Made in China Huh?
 

Hatchet

Member
Nov 21, 2011
2,405
Dillyo82 said:
Look great....Made in China Huh?

Hmmm never saw that. I'm guessing they get the blanks from there then. Unless this is a total lie...

Our engineering team uses advanced CAD (computer aided design) software to configure the drill holes and slots for optimum braking. We machine the rotors with state-of-the-art CNC (computer numerical controlled) machines in our mid-west plant with strict quality control. We guarantee a perfect fit to your vehicle, but please check the fitment information in this listing before you order. We never request a restocking fee if you do order the wrong parts.

They are local in Chicago.
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
Since posting this, I have replaced my Driver's side Tie-Rod End. While Changing it, I noticed my Rotor was Glazed.
I sanded the outer. It seems better now. I also noticed my Drive selection switch at A4wd! Not sure how long this was on! Maybe a day? Week? Is this bad?

Now that I have been paying close attention to the Pulsation, it's feels like the transmission shifting into lower gears. That would explain me not noticing it all the time. Maybe the effect is worse because I need to replace my Shocks and Motor Mounts also. I'll check my Trans Fluid as well.
 

Jkust

Member
Dec 4, 2011
946
Dillyo82 said:
Since posting this, I have replaced my Driver's side Tie-Rod End. While Changing it, I noticed my Rotor was Glazed.
I sanded the outer. It seems better now. I also noticed my Drive selection switch at A4wd! Not sure how long this was on! Maybe a day? Week? Is this bad?

Now that I have been paying close attention to the Pulsation, it's feels like the transmission shifting into lower gears. That would explain me not noticing it all the time. Maybe the effect is worse because I need to replace my Shocks and Motor Mounts also. I'll check my Trans Fluid as well.

The A4wd can be on all the time if you wish. The truck is meant for that.
 

SBUBandit

Member
Dec 5, 2011
597
Dillyo82 said:
Since posting this, I have replaced my Driver's side Tie-Rod End. While Changing it, I noticed my Rotor was Glazed.
I sanded the outer. It seems better now. I also noticed my Drive selection switch at A4wd! Not sure how long this was on! Maybe a day? Week? Is this bad?

Now that I have been paying close attention to the Pulsation, it's feels like the transmission shifting into lower gears. That would explain me not noticing it all the time. Maybe the effect is worse because I need to replace my Shocks and Motor Mounts also. I'll check my Trans Fluid as well.

The A4WD thing is no big deal, That's Automatic Four Wheel Drive. If the rear tires slip, it will automatically switch to 4WD. I prefer to keep my truck in 2WD Hi, and when I need it switch straight to 4WD. There is a potential problem some folks have found with A4WD. Let's say you pull up to an intersection in A4WD, and you get on it accelerating away. The rear tires are in some loose sand at the corner, and the fronts are on nice dry clean pavement. The Rear slips, and switches to 4WD while you are under power. The front doesn't slip AT ALL. That's alot of stress on the Transfer Case all of a sudden. I think a few have grenaded the TC when it switched suddenly. A little geometry (Roadie can even post the pretty schematic if you'd like) tells us 4WD really counts on some degree of slippage. When there's no slip, something has to break
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
Jkust said:
The A4wd can be on all the time if you wish. The truck is meant for that.

That's what I thought. I usually drive in 2WD. My wife drives it most of the time...:lipsrsealed:
 

JerryIrons

Member
Dec 20, 2011
434
I was under the impression that you should never use A4WD. Either put it in 4W when you need it, or leave it in 2W. Something to do that under certain circumstances, say the rear wheels hit a patch of ice, and the front wheels are engaged while still on dry pavement you can break the transfer case or differential.

Also for the brakes. When you resurface rotors, they are that much thinner, and easier to warp. I have noticed the cheaper rotors bought at napa warp easier. Plus my EXT weighs over 5,000 pounds with nobody in it, doesn't take much to heat up the breaks. That's when the rotors warp, when they got hot.
Also very import to make sure that where the rotors mount, you have a nice clean surface, no bumps and no "globs" of antiseize - can cause a warp.

Lastly, I don't think anybody torques the lug nuts anymore except me. Remember they will take a wheel off when your vehicle is inspected...

-Jerry
 

MAY03LT

Member
Nov 18, 2011
3,420
Delmarva
JerryIrons said:
I was under the impression that you should never use A4WD. Either put it in 4W when you need it, or leave it in 2W.

x2

JerryIrons said:
I don't think anybody torques the lug nuts anymore except me.

I do too:wootwoot:
 

Dillyo82

Original poster
Member
Aug 17, 2012
80
I was taking off my Tires and wheels to do the Bilstein HDs, Ball Joints and Sway Links.

I noticed the Brake pad Passenger Front squeaking when parking to do the work. I checked the pads and rotors in the Front. When comparing the Two Sets for the Front, the Passenger was completely gone and the Rotor was worse than the Drivers side. Also, the Driver's side had almost half of a Pad left.

Checked slide pins and brackets...all OK.

What could be causing this? This might be my Rotor Warpage problem. If the Passenger side is wearing at twice the rate, this means it is hanging on the Rotor right? Is there a proportioning adjustment or valve that could be bad? Could the Caliper need rebuilding?
 

SBUBandit

Member
Dec 5, 2011
597
Dillyo82 said:
I was taking off my Tires and wheels to do the Bilstein HDs, Ball Joints and Sway Links.

I noticed the Brake pad Passenger Front squeaking when parking to do the work. I checked the pads and rotors in the Front. When comparing the Two Sets for the Front, the Passenger was completely gone and the Rotor was worse than the Drivers side. Also, the Driver's side had almost half of a Pad left.

Checked slide pins and brackets...all OK.

What could be causing this? This might be my Rotor Warpage problem. If the Passenger side is wearing at twice the rate, this means it is hanging on the Rotor right? Is there a proportioning adjustment or valve that could be bad? Could the Caliper need rebuilding?

I have a similar issue on my Taurus, when i hit the brakes it tries to hang a left, which tells me the left front brake is grabbing first. My guess in both my case and yours is a caliper.
 

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