font brake judder;brake warp or worn bushes

[Timbuick]

Hi guys, when i bought my GN last year, the brakes juddered when used. The vendor replaced the rotars, but they still judder and now its much worse.It just occurred to me, but do these cars suffer from badly worn front bushings that would cause judder under braking?
Rolled the car backwards (reverse) down a small incline and no judder when braking.
Whats the wise money on; bushes or brakes?

 

[charlief1]

Front end parts and rotor warpage are very hard to figure out for some. See how much play you have in the steering and it should tell you what you need to replace. If it's in the steering wheel then it's the rotors/steering assembly parts. If it's in the total car then it's the rear end.

Learning to sppeel is a good thin. LOL

 

[Timbuick]

Thanks for the advise, I already have the brake parts so it will have to be a part by part check. I.e if it continues, i'll dig deeper, but the car handles well except for the braking condition.

As for the spelling, what's the problem? 'Rotars'? we call'em 'discs' over here:wink:

 

[charlief1]

I was joking Tim. That's why there was a LOL at the end.

It sounds more like you have some linkage that may be loose than a warped rotor shudder.

 

[Timbuick]

Charlie, no offence take at all:smile:, thanks for the input. I think you are right about it possibly being the rear of the car.
I went for a highway blast today, pulled off and cruised to slow down and then applied only the E-brake to pull the car up. it juddered as much as ever! I'm going to pull the rear drums and check them. They are aluminum and I reckon they may be warped.

 

[charlief1]

Get rid of the the aluminum rear drums. They are prone to some serious problems. They warp much easier and will blow up if if they are pushed too hard. Not a pretty thing if you know what I mean.

 

[Timbuick]

ouch! Will do!
I couldn't see rear drums listed by my usual vendors, do I just order a pair for a 1986 Buick Regal to get the correct fit?
Thanks,
Tim

 

[charlief1]

Yep. Just a normal Regal is what you need.

 

[Timbuick]

Thanks,
I removed one of the rear drums tonight. No cracks or anything dangerous, but the brake shoe were worn down to a ragged edge on the lead in part of the shoe. The drums had deep marks from the shoes around the contact part of the drum. The pattern was not even so i'm thinking that they may well be warped. Also, dont recall seeing such wear patterns on any steel drums i've used. Almost appears to have welded the brake material into the aluminium hub.

 

[charlief1]

The aluminum drums have a cast iron liner in them. If you have a big groove on it they're probibly worn out. I'd also bet that if you put them on a lathe you'd get a lot of runout.

 

[Timbuick]

OK, I should have taken pics, but I reckon they're junk. I'll replace them anyway.

 

[Timbuick]

Just for the record, i changed out the rear drums for new ones. Brakes are now msth effective, very gratifying after weeks of brake judder. thanks to Charlie for the input.
Next time you think that the front brake are warped, check the rears first!