I am replacing my rotors & pads...particularly the rear today. Is it safe to tap the rotors with a hammer to get them to release. I've got the setting screws removed (both of them per wheel), but having trouble getting them to budge.

I realize this is a remedial level question for you novice home-mechanics, but I didn't want to do damage to e-brake components if they would be affected (the e-brake is not engaged at the moment).

I ask because when replacing rotors on my SAAB I had to release tension (star-shaped thing) on the e-brake under the rotor before I could bang with the hammer to remove it. Tapping with a hammer prior to releasing the e-brake tension would have damaged their components.

Thanks in advance for any help.

 

Best not to tap on them at all, especially if reusing.

Do you have a second pair of holes in the rotors (different than the ones with retaining screws)?
If so, look closely to confirm they are threaded.
If yes, you wind appropriate sized bolts into the holes, alternately, a bit at a time
They press against the hub flange and should help you remove the rotor.

This is how all mine work, including my honda and chevy, but I don't have the newer fine Pcars against which to compare, hence the tenativeness of the reply.

So long as ebrake is in the off position it shouldn't interfere.

 

The rotors will stick to the hub if they've not been removed in a long time.

It's safe to persuade them off with a hammer but make sure they're not stuck on because the handbrake (what you call the e-brake) is applied! If you do that you'll dislodge the shoes and it's a really fiddly job reassembling them onto the hub.

Better than the hammer is to press them off. The rotors have two holes in them which will take M8 bolts. Buy a pair around 40mm long, thread size 1.25. Just use a ratchet (13mm) to turn them into the holes and they'll press the rotor off the hub. Again even if you use the bolts make sure the e-brake has been released so the shoes aren't holding the rotor on.

 

I actually cracked a rotor hat trying to use the bolts to remove a rotor that was seized on the hub. On the fronts galvanic corrosion is the cause. Once you get them off the front and clean up some of the corrosion it's usually not a problem if the car driven somewhat regularly. I'm still not sure why the rears always seem to get stuck. But after cracking a rotor hat with the bolts, I just pound the **** out of them with a big hammer until they come free. It's not an ideal solution but it works.

 

He says he's replacing the rotors too so I'd say use the hammer but only for the purpose of breaking them free, not trying to actually move them (by tapping them from the inside).

I usually spin them and tap each stud lightly once or twice, then the space between the studs once or twice and then begin backing them off with the m8(I think) bolts) at 180 deg. 2 turns on one, 2 turns on the other, 2 turns on the first, repeat...

If you're replacing the rotors you're fine to do a little more persuading with the hammer, but you really only need to break them free so it shouldn't take much. I just did mine a couple of weeks ago and with the bolts to back it out it's not too bad (and the rotors were REALLY BAD). Wish my other cars were that easy.

 

Just did my front rotors last weekend.. My rear rotors came off using the M8 bolts no problem (just make sure you release the handbrake before you try to take off the rear rotors.. I didn't and had a ton of fun afterwards.. ). Teh rear bearing is a HONKING thing that will take a few whacks to the rotor with a rubber mallet.

My front rotors were FROZEN on the spindles and broke the bolts that threaded holes are supplied on the rotors AND broke bolts when I tried to place new threaded holes. So I actually had to remove the spindles and beat the heck out of them to break them free of the spindles... It took about 1 minute once the spindle was off the car.. protected the grease with a rag while doing it and put the bearing back on the car. Worked fantastic.

Good luck,

Curt
________
79 928 5sp silver blk
02 Boxster 5sp blk/blk/blk

 

Please replace the expression "hammer" with "large rubber hammer". Allows the user to accomplish the end purpose, plus take out accumulated frustration on the helpless vehicle, without leaving incriminating marks or damage.

 

"rubber hammer?" I prefer a nice 3-lb sledge for this purpose. One of my favorite tools along with my sawzall and big torque wrench.

Your consideration of the emergency brake hardware is insightful but that should not be a problem. It also does not freeze the rotor to the hub. It will need to be released to get the hub off but, since these are parking brakes and not "stopping" brakes, there will not be a groove cut into the drum and the shoes won't interfere with getting it off.

Squirt your favorite penetrating oil onto the centering flange and then tap, with increasing vigor, on the inside and outside of the rotor until it cracks free. Enjoy!

 

Wow, thanks guys. I typically don't get that much response in short order...especially with my remedial type questions. This was terrific and very insightful. Thank you guys VERY much.

I've bought new rotors to replace these (what look to be originals). So, I think I shall proceed with caution, but use the hammer as I do not have the required bolts you mention and I'm 45 min. away from the nearest hardware store that is likely to have something so specific in size....not to mention clouds look like they are trying to congregate outside to interrupt my job, so I had better get to it.

Thanks again!

 

They are pretty common you can probably find 2 somewhere on the car and "borrow".
Maybe off that Saab?

Its an important aid. You can put a little tension on them, then pop it with the hammer.

 

Nick--

The rotors are a fit on the hub and the wheel, loose on the studs. If the rears won't cooperate, put the wheels back on with half torque, then go do a few hard stops forward and back with foot on both pedals. You may be able to do this with the car still on stands, wheels off. There's usually enough movement that way to break them loose.

The e-brake grabs a mini-drum surface inside the rotor. If the pads have been dragging there's a risk that they've built a small lip that will make the rotor hang up. At a recent rear wheel bearing clinic, we found that it's essential to have the emergency brake released to get the rotors off... Imagine that! If the e-brake needs adjusting, you can reach in to the little start wheel through a convenient hole, and using a screwdriver turn the wheel to unload the shoes.

 

Rob Edwards: idiotproofing your 928 experience since 2006.

 

Rob, I was all for letting you continue in anonymity. It was my fault too.

 

I got them off and, like always, I was fretting a bit too much. I'm just the opposite of "heavy handed"...always afraid I'm gonna damage something and proceed with caution (too much of it). Turns out I just needed to drink a beer and butch it up a bit. A few good taps while rotating the rotor proved the remedy of the day.

BTW, I read how fragile the pad sensors are....NO JOKE. Even with my extra precautionary style, I still managed to flake off some of the material. I re-installed them with good affect so far. However, I plan on refinishing my calipers in the near future and will order some replacement sensors and new brake lines.

Thanks again guys....I've said it many times over, but I don't know what I would do without this resource and friendly people like yourselves.

 

On those wear sensors, they seem to go together a lot safer if you use a small file to clean all the paint out of the cutouts in the pad backing plate before installing the sensors. For later reuse, they come out easier if they don't have the paint in there, and also if the openings are scrubbed with a small wire brush or toothbrush to get the old brake dust and crud out.