My brake issues

[Kraw]

had the front ball joints replaced a few weeks ago. Dealer said I needed new front brake pads and it would be $250. I said no thanks, I'll do it myself.

So, I search, read all the threads here. Read the bullitt archive info.

Take off old pads (front only), rotors were fine. Never had any peddle feel or warp feeling. Replaced pads, worked fine. After about 5 miles of driving I noticed that the wheel would shake when I hit the brakes in the 35-45mph range. Didn't feel anything in the peddle

Get home, I can feel the heat from the right front side. I also recall having to downshift going up hills and not really needing to hold the brakes on a hill.

So, I bleed the brakes, starting RR, LR, FR, FL. I noticed when I took the front right wheel off the ground, I could hardly turn it. So I pull the caliper, check the slides, cleaned everything real good, put them back on. Worked fine.

5 or so miles later on down the road, same thing.

My conclusion is the caliper is bad. It's not 100% intermittent, it's more "grabbing" then it's normal. Seems to not be an issue until I get a few miles and about 45mph.

Can it be rebuilt? What would cause it to do this. I used the old brake pad and a C Clamp to compress. One thing I didn't do was open the reservoir. I have since bled the system, if there was any excess pressure, wouldn't this resolve it?

Should I just buy a new one? What does a new one cost? The wife's pretty pissed thinking I can't do ****. She says take it to the dealer. I say **** that, I can spend $400 on something else. I would like to do the Bullitt brakes, but don't want to spend that sort of money on the car now, not knowing how much longer we may have it.

Ideas?

 

[BobHyatt]

fix

It is very rare for a caliper to go bad. It happens, but it usually is a result of the rubber dust/water boot cracking, allowing water (from rain) into the caliper where it can rust the piston to the cylinder.

I'd bet most anything your problem is related to the floating caliper pins. Remove the caliper and hang it from the front spring or something. Remove the caliper bracket. Clean both of the holes the pins go in. I use a rifle-cleaning brass brush, but most anything will do. Don't scratch it up or gouge it however. But get it clean. Take the caliper pins and clean them carefully. If they are rough, use crocus cloth or very find emory paper (or even a dremel with a fine steel brush wheel) and get the roughness off. Now use some good high-quality caliper brake grease (advance/auto-zone/etc sell this in a bottle with a brush on the cap) and grease both pins and slide them into their bores, turn them, repeat a couple of times to make sure everything is coated. re-assemble and I'll bet you won't have hanging.

But one warning. I have seen this same thing caused by the _rear_ calipers. One of them can stick (same floating pin problem) and overheat, causing the brake fluid in the caliper to boil and pressurize the rest of the brake system and make it look like the fronts are bad.

If you check all 4 wheels and follow the steps above, it is very unlikely you will have any further problems.

After the above, get in, pump the brakes up, then try to turn each wheel with it jacked off the ground. Resistance is normal, but not a lot. If the resistance goes way up after you pump, and does not go back down, something is still sticking and now I would look at the caliper piston very carefully to see if it is rusted/pitted or if there is trash in the line which can cause the piston to bind on return.

 

[Kraw]

I do plan on cleaning/lubing the pins. I checked them both, they still had grease on them and slid fine

I'll do that anyways, as I figure it won't hurt


isn't it odd that it didn't happen until I changed the pads? Could it have been this way with the worn pads (74k miles) and I never noticed?

The 2 pins are where the caliper bolts to the caliper bracket right?

 

[BobHyatt]

I do plan on cleaning/lubing the pins. I checked them both, they still had grease on them and slid fine

I'll do that anyways, as I figure it won't hurt


isn't it odd that it didn't happen until I changed the pads? Could it have been this way with the worn pads (74k miles) and I never noticed?

The 2 pins are where the caliper bolts to the caliper bracket right?

Right. the two pins are what the two small bolts go in that hold the caliper to the bracket.

This isn't that uncommon. You added thicker pads, which moves everything a bit, and any roughness or binding could easily be a result of that bit of movement... Or it could be something else. But almost certainly related to the pad replacement. If you only worked on the front, the problem is likely located on the front.

But don't forget the rear before you give up, and checking/cleaning all the pins/bores..

 

[Kilgore Trout]

The caliper slide pins must always be lubed and it sounds like they are freezing up.

AutoZone sells calipers for your car, they are very cheap and come powder coated in various colors.

Did the back of the pads have shims on them? Have the rotors never been turned? If the pads have shims and the rotors have never been turned then remove the shims you do not need them they are to take up the thickness that was machined off a turned rotor...

 

[BobHyatt]

The caliper slide pins must always be lubed and it sounds like they are freezing up.

AutoZone sells calipers for your car, they are very cheap and come powder coated in various colors.

Did the back of the pads have shims on them? Have the rotors never been turned? If the pads have shims and the rotors have never been turned then remove the shims you do not need them they are to take up the thickness that was machined off a turned rotor...

The shims are not there to provide accurate spacing. They quieten down the typical squealing disk brakes make, by providing a more "slippery" surface between the pad and the caliper itself that reduces the squeal factor significantly. Brand new vehicles come with those shims and their rotors are not undersized at all...

Typically you only turn a rotor .010-.020 to clean it up. Those shims are far thicker than that. The caliper piston has way more than enough travel to handle that extra .02 or so...

 

[Kraw]

the rotors weren't turned. I would order new ones before turning.

I don't recall any shims. What do they look like? I just bought pads that had the 4 gold color clips that go on the ends. I don't think that's the problem as the left side works fine, it's only the right side

and I didn't do anything on the rear. Just bled the brakes.

I'm 100% positive it's the front right. When you walk by it after you drive it, you can feel the heat come off of it. Also, when I had hte tire off, I could barely turn the rotor.

What sort of grease? Just any high temp grease? I think I read that in another post. I'll be going to Autozone this afternoon.

Ballpark price on a basic caliper?

 

[Kilgore Trout]

The shims are not there to provide accurate spacing. They quieten down the typical squealing disk brakes make, by providing a more "slippery" surface between the pad and the caliper itself that reduces the squeal factor significantly. Brand new vehicles come with those shims and their rotors are not undersized at all...

Typically you only turn a rotor .010-.020 to clean it up. Those shims are far thicker than that. The caliper piston has way more than enough travel to handle that extra .02 or so...

Nope, and I know this because I just did the brakes and had to remove the shims because the rotors had never been turned. The shims being there to quiet squeaks is a common misconception. They are there to fill space. The stock OEM have no shim the parts counter replacement has a shim. This is for the reasons I mentioned that you incorrectly corrected me on.

 

[Kraw]

well, I bought the motorcraft pads, do they have shims? what do they look like? I know what shims look like for carpentry

 

[Mustang5L5]

I vote slide pins binding up.


Was one pad on the frint right worn down more than the other??


Did both pistons push in all the way easily??

 

[Kraw]

pistons pushed fine, I didn't notice either pad wearing more

I picked up some grey snot, will try that one night when I have more time.

The more I thought about it, the more it made sense. The top bolt came out easy, I didn't even have to hold the pin. Granted, it did turn, but I could never get the bottom bolt out. It just turned and turned

 

[Mustang5L5]

top pin is my guess.

 

[ForPointSex]

Get some new rotors. Only $50/each for motorcraft at the dealer.

 

[1Phat5Liter]

Check out your local Autozone/PepBoys for some new brake caliper pins/hardware kits. They're about $5 per kit. And while you're at it, just get new Rotors, etc.

 

[BobHyatt]

Nope, and I know this because I just did the brakes and had to remove the shims because the rotors had never been turned. The shims being there to quiet squeaks is a common misconception. They are there to fill space. The stock OEM have no shim the parts counter replacement has a shim. This is for the reasons I mentioned that you incorrectly corrected me on.

Sorry but 99% of the stock cars I replace brakes on have shims right out of the dealer's showroom. I just did my ranger at 40K miles, and the factory pads had the usual clip-on shims... Ditto for my wife's honda accord, and several other recent brake jobs that were the first time those brakes had been adjusted. A quick check of a couple of service manuals will convince you almost everyone uses 'em. And not for clearance. The piston has at least 1"+ of travel. .020 of turning is not going to affect that at all.

 

[BobHyatt]

BTW, if you need rotors, you can't beat O'reilly now. They sell lifetime warranty rotors, something I have not found anywhere else. Advanced sells lifetime warranty Bendix ceramic pads as well, so buy 'em all once and then just replace as needed with no more cost...

 

[steve_stang2003]

BTW, if you need rotors, you can't beat O'reilly now. They sell lifetime warranty rotors, something I have not found anywhere else. Advanced sells lifetime warranty Bendix ceramic pads as well, so buy 'em all once and then just replace as needed with no more cost...

+1 on the Bendix pads.
I use them on all my cars and the kit for the Mustang comes with all the clips, shims, grease etc.
Very high quality ceramic stuff and the dust factor is pretty low.
Make sure to bed the brakes by making a couple of well timed panic stops and you will be good to go!

I agree that his pins are sticking and I would replace the rotors as well because if they overheated they might be warped.
Make sure to use the high temperature brake grease for the pins and not ordinary grease.

One comment on the rears sticking and causing the fluid to boil making it look like a front brake problem. I had this exact problem on a T-bird. It drove me crazy because it was intermittent. It was a drum rear but the result was the same.

Also I believe the REAR calipers or brackets have shims to center the caliper.

 

[Kilgore Trout]

Ah so now a THIRD use for the shims: "centering the caliper"

 

[steve_stang2003]

Ah so now a THIRD use for the shims: "centering the caliper"

Yep.
I believe MMFF or one of the rags did an SSB brake swap recently and they made a point of mentioning the shims on the rears to center the pads.
I'll see if I can find it.

Oh look at this, I did find it:

Here ya go:

http://www.mustang50magazine.com/techarticles/m5lp_0710_fox_mustang_5_lug_swap/brake_bleeding.html

It's for a Fox Body, but the principle is the same in that the caliper or rotor depending upon how you look at it, has to be centered.

BTW you can stop laughing now.......

 

[Kraw]

I plan on replacing the rotors at the same time.

now, what are these shims? Are they the brass colored pieces that clip in each end of the caliper bracket?