New brake rotors too large (thick) ?

[ah1988ford]

I bought new front brake rotors from autozone. I installed them and the calpiers rub on the new rotors so much that it causes a major drag, so bad the truck isnt drivable. So I took the wheel off to see what was going on and the caliper dosent "retract" or "reset" back far enough to clear the rotors. When I was installing the rotors I used a c-clamp to compress the pistons so I could install them in the new rotors, they had plenty of clearace when I compressed them. But when I put the calpiers back on and pump the brake a few times they clamp down on the rotors and then retract just a little. Once I press the brake pedal the front wheels almost lock up to where I can free them by hand. I put the old rotor back on the passenger side and the calper self adjusts properly, it works fine with the old rotor. So are my new rotors too big, are they too thick? I noticed on of the rotors wasnt completley round I could spin ot with the calpier removed and clearly see a "whobble" it is obviously out of round.
I bought the rotors from auto zone and they said NEW the rotors should be 31.6mm thick.
I measured mine with a digital calpier and it measured 31.86mm

It is just slightly larger, should .2mm make that much of a diffrence? I am using my old brake pads and calipers so they are worn, I would thing the slightly worn pads would make up for the .2mm diffrence?

Thoughts, questions, comments?

 

[wildman7798]

It sounds as if you may have stuck calipers? Do you know how old they are or have you ever had them apart? It's possible as the old pads and rotors wore - the pistons extend farther and farther into the bore. If your brake system has excessive moisture or is old fluid as most do, the caliper cylinder bore could have corroded some. Now you are putting the pistons back into an area of the bore that hasn't been used for some time, the pistons could be clamping down and then getting hung up on the return. Pretty common problem once the calipers get to be 15 or 20 years old or older. They are easy to rebuild if you have air and a hone - kits for them are cheap.

 

[riotwarrior]

^^^ I cannot speak to AZ rotors sorry, however the above info is true especially in regards to OLD pads on NEW rotors, not the best that's for certain. I also agree with off center rotor, take that back and get another!

Those caliper slides need to be cleaned thoroughly and some form of lube used.

I personally use HI temp anti-seize myself on the slide surfaces on my vehicles, this has given me fantastic results for many years.

Do you have to rubber/steel encapsulated pins or the T plate and bowed spring lock bolt assembly? Regardless I'm sure a very clean slide surface and some lube will be your friend and go a long ways to making things better.

Also could it be a sticking caliper that's not functioning correctly? Just something to consider in your quest.

 

[OLDBULL8]

Brake fluid absorbs moisture like crazy, big word for it cant' remember it. Thats one reason why the MC was changed to a reservoir in place of the whole top of the MC removable, and a very small cap on the can of fluid. Really, brake system fluid should be changed/flushed every couple of years. That moisture tends to rust the insides, not quite as bad as they use to, specially disc brake caliper cylinders, they hold a lot of fluid as compared to drum brake cylinders. Synthetic brake fluid won't absorb moisture like DOT3 and 4, don't mix DOT5 synthetic with the other, they don't mix well.

Take your old and new rotors and lay them on a flat surface, they should be the same height. IIRC PSD rotors have more offset and a little thicker.

 

[tbrumm]

Brake fluid absorbs moisture like crazy, big word for it cant' remember it. QUOTE]

The big word you were looking for OLDBULL8 is "hydrophyllic" if I spelled it right - meaning "water loving". This is opposite of "hydrophobic" meaning "water fearing" or "water hating".

I know this post doesn't help the OP, but ya gotta love big words sometimes. I am with the other guys on this; if those slide rails are rough, rusty, grungy, etc. it can really affect the caliper movement.

 

[ah1988ford]

Alright, the plan is new calipers, brake pads and shoes. I will also clean the guides or where ever the calipers/pads rub and lube them.
Are there any brands of calipers, pads and shoes I should look out for and avoid before I drop the cash?
The calipers look like they are probably factory the truck has only 130,000mi. on it, and the rotors were heavily pitted and looked almost rotted same as the rear drums. The guys that inspected the truck said the pads were fine but they do look "glazed". Pads and shoes arent too expensive so I will just go ahead and replace them along with the calipers and have a completley re-built brake system except the booster. The new calipers are exactly the same size as the old ones, the new ones were just substantially thicker. This truck has been sitting for close to 4yrs in my possesion and who know how long it was sitting on the farm I got it off of. Everything seems to be falling apart, the brakes, tires, electrical, fuel system. I know it like the back of my hand now. This thing has been a major pita, hopefully it will be over with soon! I really appreaicate all of the help you guys keep me from getting rid of it, some days I feel like giving up and putting a for sale sign in the windowl lol.

I think the word is hydroscopic?????
I have flushed new fluid throught the system several time over, replacing all of the lines and wheel cyliders along with a master cylinder and having to bleed the air out everytime.I dont have fuzzy feeling twoards this truck.........

 

[tbrumm]

As long as you are installing new calipers and will have to bleed the brakes anyway, might be a good time to replace those front brake hoses to. It is easy for me to spend other peoples' money and make more work for them but now would be the time to do it. The hoses are probably dry rotted anyway.

 

[OLDBULL8]

Yeah "HYDROSCOPIC" thats it. When you get to be my age your lucky to remember to take your wiener out before ya ***.

 

[riotwarrior]

I"d look into buying loaded calipers in other words they come with pad's already, don't buy twice or pay more for separates!

How are those soft brake lines? Need replacement?? Nows a good time if they show signs of cracking and such, and also they may be degraded internally and causing caliper to stick too! Like a heart valve a small piece may be allowing fluid to caliper but acting like a valve and making the fluid return really slow acting like a locked caliper...don't ask ....it's for real this symptom..!!!!

 

[ah1988ford]

I"d look into buying loaded calipers in other words they come with pad's already, don't buy twice or pay more for separates!

How are those soft brake lines? Need replacement?? Nows a good time if they show signs of cracking and such, and also they may be degraded internally and causing caliper to stick too! Like a heart valve a small piece may be allowing fluid to caliper but acting like a valve and making the fluid return really slow acting like a locked caliper...don't ask ....it's for real this symptom..!!!!

I already replaced the rubber lines they were shot, probably factory. Thoes were a pita too, I would like to hit whoever designed that with a spiked bat. Its nearly impossibble to hold the hard line that is behind that bracket. I ended up not being able to get those little clip things on that hold the line in place back in their little slot so I just used a hose clamp on both sides ..... easy and holds prettly good.
Good to know, I was looking at the diffrent calipers some were loaded and others weren't I was like what does that mean?
Lmao Oldbull, Im 16 and I am constantly forgetting stuff..... I have a terrible memory my teachers hate me. I cant spell either if you havent noticed.

 

[chris142]

Use a stiff brush and brake cleaner to clean the brackets. Then buy new pins and instal those with grease on them where the caliper slides.

 

[cpdenton]

Absolutely buy the new pins that hold the calipers. The rubber in the center that holds them gets hard and for about 5 bucks you can replace them. Worth every penny.

 

[riotwarrior]

I already replaced the rubber lines they were shot, probably factory. Thoes were a pita too, I would like to hit whoever designed that with a spiked bat. Its nearly impossibble to hold the hard line that is behind that bracket. I ended up not being able to get those little clip things on that hold the line in place back in their little slot so I just used a hose clamp on both sides ..... easy and holds prettly good.
Good to know, I was looking at the diffrent calipers some were loaded and others weren't I was like what does that mean?
Lmao Oldbull, Im 16 and I am constantly forgetting stuff..... I have a terrible memory my teachers hate me. I cant spell either if you havent noticed.

I applaude your efforts as a young man working on yer ride! Kudos!

Memory what was I saying oh ya...look something shiny! ROFL

Yes a pair of loaded calipers could be less expensive than a set of pads and two calipers separate, look into it!!

Don't be shy about asking questions here, better to show how smart ya are and ask a silly question than to prove otherwise by having to fix a silly avoidable mistake!

We are here to help just remember READ lots!

 

[f-two-fiddy]

Raybestos Professional

The best out there, for a minimal amount more. rockauto.com has loaded calipers for $80/ea including a $10 core/ea.

I've never had a problem with a Raybestos Pro Rotor. Never had one warp. They run true, and long. They last twice as long as the cheap crap that most auto parts chains try to pawn off.

One thing though. IF the hub is integral with the rotor. Knock the bearing races out, and replace them with Timkens. Most rotors come with cheap Chinese races installed. I had one of them fail at a most inopportune time.

 

[Dave Barbieri]

Speaking of cheap Chinese parts.....

Yesterday, I received my Rock Auto order for pads (PGD668C) and rotors (96154R) for one of our cars. Both boxes are stamped Raybestos Professional Grade. Both are stamped "Made in China".

Finding non-Chinese aftermarket parts is becoming a real challenge. I was not able to find Made in America pads or rotors for my truck. Had to order them from RA and wait for them to get here. NO ONE (ABC, Pep Boys, AZ, O'Reilly's) carries American brands here in east Texas. When you hold the store brand box in your hands and check it, you find "Made in China" on the back. I didn't check NAPA, so I don't know about them.