Georgia Fiero Club Forum

All Things Fiero => Tech Tips, Tech Questions => Topic started by: NoobKevin on October 10, 2019, 10:56:52 am

Title: Rear Brakes grinding
Post by: NoobKevin on October 10, 2019, 10:56:52 am

Hi All,

I have finished with the engine. Now when I test drive I get a very obvious grinding noise from the rear. It could be the parking brake. But how does the parking brake engage the rotor?

Kevin

Title: Re: Rear Brakes grinding
Post by: TopNotch on October 10, 2019, 01:21:56 pm

Does the noise happen all the time, or just when you apply the brakes? If all the time, could be a rubbing dust shield or a bearing.

Title: Re: Rear Brakes grinding
Post by: Fierofool on October 10, 2019, 03:36:11 pm

Is it more pronounced when turning one direction than in the other?  If so, it probably is the dust shield.

If you had the engine out and disconnected the hubs from the axels, not following the correct torquing procedure when reinstalling the axel can cause the hub bearings to fail.  In addition, if the nut was taken off the axel shaft, the nut should be replaced with a new one. 

Title: Re: Rear Brakes grinding
Post by: GTRS Fiero on October 10, 2019, 05:09:37 pm

The shields are easy to check, and you can do it on a stock Fiero, without lifting the Fiero.

Title: Re: Rear Brakes grinding
Post by: GTRS Fiero on October 10, 2019, 11:52:10 pm

Also check the insides of your wheels.  There is not a lot of clearance with the stock wheels.  Maybe a caliper or something is rubbing.

Title: Re: Rear Brakes grinding
Post by: NoobKevin on October 12, 2019, 02:03:38 pm

It is the shields. Is it normal for the rotors to move enough to press against the shields? I have bent the shields as far away as I can.

Title: Re: Rear Brakes grinding
Post by: Fierofool on October 12, 2019, 05:19:04 pm

There isn't a lot of clearance and the rotors can flex enough.  Even a little kink in the shield can cause a rub.  On the other side of the issue is that if you get them too far away, they can pick up stones that can hang against the brake pads and embed in the leading edge enough that it won't come out when you back up.  The rear brakes are very particular and they must be reassembled and installed in a particular way to prevent problems. 

Title: Re: Rear Brakes grinding
Post by: GTRS Fiero on October 12, 2019, 08:22:19 pm

I'd slide a piece of paper in there to find out where the rub is.

Title: Re: Rear Brakes grinding
Post by: mweldon on October 13, 2019, 03:59:14 pm

Furthermore sometimes a leading bit or chunk of a pad can chip off and embed itself further back and grind away....

You said it's more pronounced when turning one direction vs another.... Are you sure it's not a bearing?  Have you done a 3-9, 12-6 wobble test?

Title: Re: Rear Brakes grinding
Post by: GTRS Fiero on October 13, 2019, 11:07:56 pm

I wonder if the brakes are adjusted properly.