Rusted & Seized Front Brake Rotors

[Pohonasin]

I decided after 150K miles to change my front Wheel Bearings / Hubs. Watched 100 online videos, purchased the materials and got to work. Jacked up the truck, removed the front driver side wheel, and brake caliper then tried to remove the brake rotor....UGH. NJ salt belt has rusted it to the knuckle. Tried to pound it off with a hand sledge, then moved to a larger one, but no luck. Sprayed the Sh*t out of it with PB Blaster, let it sit and tried again, but nothing. I even heated it with a propane torch, but still nothing. If I can't get the rotor off, then I can't get the bearing off. I even looked for a screw holding it place, but found nothing. and yes, I removed the retaining clips, so that was not the issue. I saw a video online of a guy using a class 8 bolt and nut, going through the caliper mounting hole and pushing the rotor off from the back, but I am afraid to break the cast steel knuckle. Anyone have any suggestions? I have realized that I will have to replace the rotors anyway, so If I have to destroy them in the process, that is OK.

 

[Jeepwalker]

Two ideas:

1) Support the lower A-arm with a length of 2" square tube or pipe. If your truck is up on jackstands, put a length of square tube or pipe under the lower ball joint (the stem will fit inside the tube) and the other end on concrete. That way when you hammer you are transmitting a lot more of the force on the wheel hub ...rather than the lower control arm bouncing all over with each hammer blow. But you'll still have to hammer the heck out of them. Consider #2.

2) Remove the entire knuckle and take the knuckles/hubs to a machine shop and have them press the wheel bearing off the knuckle -- from the backside. At this point this #2 option would probably be the easiest thing for you. Just take the knuckles in and the shop will give them back to you with the hubs pressed off. Easy as that. The shop may do them while you wait if you are lucky. Cost shouldn't be too bad. Hand thread the hub retaining bolts back in so the shop can loosen & press on the bolts if they need to (but tell them you need those bolts back for SURE!!). When I've done mine I pressed on each bolt and worked the hub out gradually. Yeah ...they can be in TIGHT ..I agree, but a press makes easy work out of it w/o damaging anything.

I've done it both ways 1-2. If they're as tight as yours are #2 is the way to go. Why fight them? I've literally beat a hub for a couple hours in the past (taking breaks) ..and a press can work them of in minutes. Plus pressing out doesn't beat the crap out of the lower ball joints and honestly it's a lot less stressful on you and the truck. The only two things you need to do extra is undo the tie rod/s and lower B/J's. A Front End Suspension Removal Kit (Like below) makes that job quick & painless. I have a similar kit and over the yrs it's been one of the better things I've bought. But you can rent the same kit for free from a parts store. You basically only need to use the long puller on the right of the lower picture. That's the only puller you need for those joints.

It's also good to remove the knuckle so you can inspect the lower B-J's. Those were loose on my tk and needed replacing ....even though all the other steering parts were tight. I wouldn't be surprised with 150k if yours are loose and need replacing too. If they are, NOW is the time to replace them! Press out/in new ball joints (using a ball joint press which you can also rent from a part's store). TRW was the original supplier to Ram ...and their replacement B-J's are greaseable. Better than using no-namer imports. That's what I used. RockAuto has them. Good luck!!

 

[EdGs]

So glad I live where there's no road salt.

I wonder if you can spray the axle splines with PB Blaster, loosen the 3 hub bolts, and remove the hub with rotor attached.

If you have a 2wd, no axle splines to worry about.

 

[Jeepwalker]

I always check every rotor I install on my vehicles with a dial indicator. More often than you know rotors come pre-warped. No amount of indexing or swapping side to side will get them to run true (enough).

Once I have them where they are 'good' I put a mark on the rotors and end of lug stud with a paint marker. Then slatther a thin coating of anti-seize on the back of the rotor and hub face. Never have a problem with them rusting.

If the OP is into super-maintenance. Now would be a good time to remove the boots around each caliper piston and put some lube in there to prevent rusting where the inside of the boot rides. But this involves removing the calipar and popping out the pistons (with compressed air). Remove the dust boot and re-lube the piston bore ESPECIALLY the lip around where the dust boot sits. Because once rust creeps under and around the dust boot it can score the piston. Make it harder to retract. Keeping it lubed up (and/or removing any rust which HAS begun in that lip ...with a screwdriver or pick) should extend the life of your truck's rotors for many more years.

Plus it's a good time to replace all fluid. A caliper can be super-rusty on the outside but look brand new on the inside ..even if it's 30 years old. *If* a guy replaces the fluid once in a while. The weakness is when rust creeps around and under the dust boot after xx number of years. Putting in some grease over that (disc brake lube) will help prevent rust from doing that.

Hopefully your calipers are still good. But if you DO need to replace them, I would buy new, not rebuilt. Rebuilt calipers they usually sandblast the entire bore which ruins the bore. And use poorly chrome-plated pistons ...which quickly rust up (here in the North). Better to spend a little more and get a brand new Zinc-plated or galvanized caliper machined to spec.

 

[Mojo88]

I always check every rotor I install on my vehicles with a dial indicator. More often than you know rotors come pre-warped. No amount of indexing or swapping side to side will get them to run true (enough).......

I use the dial indicator trick every single time, on every single rotor. Regarding brand new rotors, I have NEVER found a 'warped' rotor. Rather I have found rust and/or crud somewhere on the mating surfaces, preventing the rotor from laying flat against the hub. Thorough cleaning of the inside of rotor and front surface of hub yields acceptable runout every time for me. I strive to get as close to .001" runout as possible.

Most shops are not taking the extra time for this step, which is a big mistake IMO. Just another reason I prefer doing things myself, if possible...........

@Pohonasin - for REALLY stuck rotors, I use oxy/acet torch. Heat up the rotor surface just around where the hub sticks through. Sometimes it takes a lot of heat. Obviously, don't melt things in the process. Regardless of how much rust, the heat will loosen it.

 

[Travis8352]

Buy a couple bolts nuts and washers amd use those to press the rotor off thru fhe caliper mounting holes. I had to do that with mine worked like a charm

 

[joesstripclub]

If there is a threaded hole on the face around the wheel studs, these work like a charm to remove the rotor. Just have to find a bolt with the correct threads and it will push it right off the hub. Otherwise I've had good luck spraying PB blaster into the holes around each wheel stud while you rotate it around. Let it sit for a bit then work your way around with a sledge. You might have success just by letting the PB Blaster sit for a day and trying again. Get new rotors with a coated face or put anti seize on the faces for the next time you take them off. If you do the outside it helps to get the wheels off if you have issues, but the tire shop will probably make a mess of it on your next tire change.

 

[Jeepwalker]

Regarding brand new rotors, I have NEVER found a 'warped' rotor.

Lucky you. I sure have. I have a lot of vehicles to feed though. And like you...they rust up our way.

Just last summer I bought a Pr of cheap Detroit axle rotors for a car. I think it was a pr for like $28 or $32. Definitely a good deal if they're legit. I never buy Detroit Axle stuff but I was tempted by cheap rotors. Both were 'warped'. One was like .006" ..maybe more. That was bench-tested on a brand new Moog hub/knuckle/bearing assembly in a vise which had no run-out at the outer hub face. Brand new assembly. I had two new knuck/hub assemblies and the rotors were the same on each no matter where you rotated them to. No crud under the rotor/s. I've had several pre-warped rotors over the yrs. There must have been chips under then when they were machined.

When Napa first came out with their 'Silver' line of import parts back in the early 00's the China rotors then were famous for being crap. I took a lot of rotors back any my buddy there said they were getting a lot back. Eventually Napa went with a different supplier and they were a lot better. But by then I'd stopped buying NAPA Silver rotors altogether.

I sent those Detroit Axle rotors back to Amazon last summer and bought a better set of Raybestos and they were perfectly on the money. I wouldn't install a rotor w/o checking run-out. Unless a guy doesn't mind wobbly brakes. The funny thing is a lot of drivers don't 'feel' wobbly brakes if they're just a little warped. I sure do!

Brakes with rotors which have 0" run-out are a thing of joy!

 

[Travis8352]

When i say it worked i mean i spent a weekend with the sledge and every penetrating oil known to man before trying the nuts and bolts press method and had both rotors off in 5 minutes

 

[Seedog]

Mixing acetone and reg trans fluid makes the best rust penetrating fluid. The gov did this test of all penetrating fluids, this mixture was the best by far.

 

[Tominator223]

Clean around the rotor and hub with a wire wheel really good. Then spray whatever you chose. Before trying to remove.

 

[Bob Horowski]

Mojo88 is 100% correct a propane torch is adequate for melting solder while doing plumbing work. Oxy/Acetylene or Oxy/Mapp is what is needed to get the heat you need. Just don't overdo it and start melting the metal. Keep the torch moving.

 

[Mojo88]

Mojo88 is 100% correct a propane torch is adequate for melting solder while doing plumbing work. Oxy/Acetylene or Oxy/Mapp is what is needed to get the heat you need. Just don't overdo it and start melting the metal. Keep the torch moving.

Haha, thanks. I used oxy/acet to get my first frozen brake drum off more than 50 years ago, and that method still works good for me!

 

[4xdad]

i just went through the same thing with my pw. it was apita the passenger side rotor was seized one of the pins were seized. the rubber was torn on the one pin. so a good amount of pounding and cursing spraying wd on one hit it came off. the pin was the same thing spraying pounded twisted cursing and swearing. so finally it came out. for the price i got the pins and put it all back together with the pins and pads all good now

 

[Mojo88]

i just went through the same thing with my pw. it was apita the passenger side rotor was seized one of the pins were seized. the rubber was torn on the one pin. so a good amount of pounding and cursing spraying wd on one hit it came off. the pin was the same thing spraying pounded twisted cursing and swearing. so finally it came out. for the price i got the pins and put it all back together with the pins and pads all good now

I've never liked heavy pounding, too easy to damage other components, mainly bearings. But you can also harm other components as well. Heat works wonders.............

 

[Jeepwalker]

I've never liked heavy pounding, too easy to damage other components, mainly bearings. But you can also harm other components as well.

For sure! He'll be ok in this case since he's replacing the hubs. But yeah, a guy would likely damage the bearings ..and vigorous pounding with a sledge doesn't do the ball joints any good either.

 

[4xdad]

stuff can be damaged by heat too. my thing is do what you have to do. i live in the country so it’s not a 5 minute drive to crappy tire. perseverance is key and a good supply of weed

 

[Wild one]

Mixing acetone and reg trans fluid makes the best rust penetrating fluid. The gov did this test of all penetrating fluids, this mixture was the best by far.

I've never seen a government test,but have seen the Machinists tests of penetrating fluids,reason why i never throw out old tranny fluid,i always have a spray bottle of it mixed 1/2 and 1/2 with either acetone or lacquer thinner,it's still the best penetrating fluid i've ever found

 

[Seedog]

I've never seen a government test,but have seen the Machinists tests of penetrating fluids,reason why i never throw out old tranny fluid,i always have a spray bottle of it mixed 1/2 and 1/2 with either acetone or lacquer thinner,it's still the best penetrating fluid i've ever found

The navy did the trst

 

[Wild one]

I can't find the Machinists Workshop test article from 2007 at the moment,but i did find their results on google.
It was a good read when i read it years ago.

A famous test conducted by Machinist's Workshop magazine measured the "break-out torque" required to remove rusted nuts and bolts after soaking them in various penetrants. The results proved that a simple homemade 50/50 mix of automatic transmission fluid (ATF) and acetone performed best, requiring significantly less force than commercial brands. [1]

Test Results
The test evaluated how many pounds of torque were required to loosen the rusted fasteners. The lower the torque, the more effective the fluid: [1, 2]

• ATF / Acetone Mix: 53 lbs
• Kano Kroil: 106 lbs
• Liquid Wrench: 127 lbs
• PB Blaster: 214 lbs
• WD-40: 238 lbs
• No Penetrant: 516 lbs [1]

Key Takeaways

• Any oil is better than none: Using even standard WD-40 cut the required force in half compared to trying to remove the seized hardware dry. [1, 2, 3]
• The homebrew champion: The 50/50 mix of ATF and Acetone is a long-time machinist's favorite that heavily outperformed every commercial product tested. [1]
• Machinist consensus: According to discussions on Practical Machinist, professionals agree the homemade blend penetrates exceptionally well but must be shaken before use and kept in a sealed container as the acetone evaporates quickly. [1, 2, 3]