• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

New Rotors? - Advice NEEDED

Share this page

mrstinson

mrstinson

Senior Member
Offline
I just took off my front wheel last night and found that the rotor has rust on the sided and front with pitting on both. My braking is not as good as it should be and I think this may be apart of the cause.

Do I really need to replace the rotors?
If so, what is the best way to take off the rotor bolts?

I took the dust cap off as well and the greese looks clean (if not new) and I do not feel any play. So no problem there.
 
never comprimise on the brakes. you may be able to get by with getting them turned, but IMO I would just buy new ones, and start anew
 
Adam is correct. If the rotors are pitted replace them and replace the pads. If there is any question as to the operation of the calipers or rear cylinders, rebuild or replace. Also a good time to replace the brake fluid. It is important to completely purge out the old fluid and replace it every 2 years. Often over looked and results in unwanted problems. Rick
 
Yeah, but let's just quantify this a bit.

The brand new vehicle in my driveway right now (with 222 miles on it) has rust on the rotors. Minor surface rust is to be expected on cast iron rotors, especially on a car that has sat for a little while. My Spridget sits indoors between races and it always develops a light coating of rust on the rotors.
Deep pitting or heavy rust is a different story, though I think rotor runout (wobble) is actually a worse problem.
(And for the record, I just bought new Brembo rotors for my Spridget last week).
I took my rotors off the hubs with ordinary hand tools (socket set).
Changing brake fluid regularly is an excellent idea...not enough people do this.
 
Ditto to Nials comments. My rotors will rust overnight in the high humidity we've been going through lately. If you've been driving the car, and notice rust immediately afterward, then there is a caliper problem. After a drive, the rotors should be shiny on both sides. If not, then something isn't working correctly, and bears further investigation.
How many of you have noticed that your brakes grab the first time you stop after sitting overnight? Happens all the time on my Chevy van, and when I was driving new development vehicles at GM, you always made the first stop of the day a very gentle one because of the rust on the drums and rotors.
Jeff
 
The rust I see on my rotors is not surface only. The is a good deal of pitting and the rust does not rub off after a drive. I jsut ordered two new rotors and will be installing this weekend.

As far as the reemoval of the rotor bolts, how do you keep the hub from spinning? I may be able to use the brakes to stop the spinning but is there a better way? I am not sure if the brakes will hold the rotors secure enough.

I pulled the drums lastnight and found a couple of things interesting. The boot over the "calaper" ends (sorry don't know the part is accually called) is torn from when the drums were put on. That part also wobbles. Is the wobble normal?

btw: a lesson was learned lastnight. Do not remove the screw that is in the rear hub unless you intend on replacing the axle and lose some fluid. /ubbthreads/images/graemlins/grin.gif I learned this hard way. Also, if you are like me and do this the axle is a little hard to replace because it has to go back in the same way it came out. And all that time you are finding the right place, fluid is running onto your garage floor.
 
The brake cylinders do actually float a bit. The method of fastening them doesn't lend itself to anything stronger. I think it is only supposed to hold them into position and a certain amount of float is expected to kinda balance out the pressure. I haven't tried to remove the front rotors yet so I can't help you there but I'm sure someone will be along who has tackled this job. Oh and as far as the rubber boot on the end of the cylinder, I've noticed that mine are "scratched" as well. They aren't being torn all the way through but instead grooved by something that I can't remember what is right at this moment. I was very concerned when I first saw it but I've been watching it and it doesn't seem to be getting any worse. As long as they aren't being cut all the way through, this may be normal as well.
HTH,
JC
 
When I said rust on the surface, I did not mean rust forming from sitting. I meant that after driving, if rust still was on the surface of the rotors that you have a problem with the caliper(s).

Also remember that MG's have dual piston calipers. Pressure is applied to each side of the disc. There are no caliper slides as you would find on most cars. Check both sides of both discs.
 
Re: New Rotors - HUB WON'T COME OFF

I received my new rotors last night (a day early) and started on the switch. I was able to remove the rotor bolts, dust cap, cotter pin, large nut and two washers. After that, THE HUB WILL NOT BUDGE.

How can do I remove the hub and bearings? I already need to rebuild the hub due to a click when it turns. But the hub will not move and I do not see anything to grab the race and bearings.
 
Re: New Rotors - HUB WON'T COME OFF

I'll assume you have also removed the brake caliper, The hub should come off with a good tug. You should be able to wiggle the hub to the point that the front bearing should come loose and can be removed. If all that fails rig up a puller on the hub and use the small recess in the axle end and pull it off. Once it moves it should come off easy.
 
Hubs off BUT . . .

I finally got the first hub off and replaced the rotor /ubbthreads/images/graemlins/grin.gif. I finished the passenger side up and moved onto the driver side. That hub came off without a problem, but the grease is black.

Do I need to remove the bearings and regrease or is there an alternative?

Also, if i do need to pull the bearings, what is the best way to do so?

Thanks again for your help and advise.
 
Re: Hubs off BUT . . .

I just finished a complete brake rebuild on my midget, and I decided to just fit new bearings while I had everything apart. I will tell you this: I was using a piece of red oak as a drift to take the old bearings out (actually, many pieces, as they splinter after a couple hard hits), and the bearings still did not come out in one piece and they were not useable after. I've done bearings before on other cars, so I know it was not my technique, but possibly the bearings were shot, despite the absence of play in the hub. I noticed a BIG difference with the new bearings, and am glad I did them.
 
Re: Hubs off BUT . . .

If I had it apart this far I would at the very least grease the bearings but better to remove them, check them, replace them if any questions. If not replaced then clean thoroughly and grease.

Are there any shims etc?

Bruce
 
Re: Hubs off BUT . . .

Thanks for the advice. I will try tonight to remove the bearings. I do not have a piece of wood small enough to fit into the hub, but I will come up with something.

As far as shims, I did not see any or know of any. I have a 71 Midget.

I did not replace the bearings on the passanger side, I may rethink that descision and open her back up for more surgery.

I will post my progress.
 
Re: Hubs off BUT . . .

My 77 didn't have any shims either. I was able to tighten them up for a preload, and then back them off to line the cotter pin right up. There was no play at all, and the rotation was nice and smooth. If you do decide to replace the bearings, pay mind to the side labeled "thrust". That side faces the tapered spacer (the outside bearing thrust side faces in, and vice versa for the inner bearing). This is because the bearing sides, inner and outer, are not identical. I got the 411 on that in another thread when I was replacing mine. The info should also be in your shop manual.
 
Re: Hubs off BUT . . .

I don't think I seated the bearings all the way because now there is a wobble when I turn the wheel. Now I have to take it apart again and try to seat the bearings fully.

I also ready about the "thrust" side of the bearings, but thanks for the reminder.
 
Re: Hubs off BUT . . .

I think I may have bent part of the driver side hub. /ubbthreads/images/graemlins/frown.gif

I have looked around and cannot seem to find one on the internet. I am going to call some of the salvege yards around here, but I am not sure. Does anyone know where I could pick one up?
 
Re: Hubs off BUT . . .

How did you check for trueness?
 
Re: Hubs off BUT . . .

The end of the hub has been bent in. There is a definite ridge shown when I hold it next to a straight edge.
 
Back
Top