Rear Disc conversion super noisy?

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redlinegw

redlinegw

Shannon
Joined
Aug 14, 2008
Messages
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Location
Newhall, CA
I just finished a rear disc conversion on my 69 Valiant with an 8 3/4 rear end. I used a kit from Right Stuff and it all went together very easy. It makes a super loud noise when you apply the brakes normal, when I hit the brakes hard it is fine. It so freakin loud it is embarrasing. I have tried everything, turned the new rotors, scuffed and tappered the pads, made sure that the pads are installed correctly with no vibration. Right now I am wishing I would have left the drums on it stopped great. The only thing I can think of now is that I mounted the calipers in front as per the instructions, however most pics I can find of other systems show the calipers on the back. The noise is not brake squeek but a loud whirring followed by a loud rattle. I am getting pissed!
 
You need to take it apart and see what is loose or damaged. As far as the location of the caliper, it usually doesn't make any difference. Can you post some pics showing what you did?
 
What type of calipers? If they are GM type sometimes you need to shim or anti squeel the pads. Especially the outside pad. I usually put a dollop of high temp silicone where the pad rests on the caliper.
 
Yeah they are the GM calipers. I used brake squeal spray and tightened the pads by bending the ears so they fit tight onto the caliper. The sound is not a squeal it is really really loud whir and vibration rattle.
 
Are they floating type of calipers? If not than I would think the Rotor is not centered in the caliper and when you are pressing on the brakes lightly only 1 side of the pad is touching the rotor, when you stomp on the pedal hard then both pads hit the rotor and the noise is LESS loud? Maybe the mounting brackets are on backwards? The Bearing issue I mentioned above?

Just throwing out Ideas, I am about to buy the same set up for mine.
 
Did you change your axle bearings? or were they changed to non adjustable ones before on your other set up? Sounds like you are getting Brake Chatter.
 
The spacing from front to back pad has to be centered on the rotor or they will apply pressure unevenly which will quickly warp the rotor when it is warmed up. Shims will fix this.
 
Your car is po'd for putting GM parts in it. And it's letting you know. Check to see if rotor is centered in the pads, greased the caliper pins?? Spray anti squeel might not be enough. Semi metallic pads or organics?
 
Yes it has the green bearings and yes on the floating caliper. Greased the pins as well. I am taking the car to the local brake guru on Monday. I am done! I have had the calipers on and off 10 times. The calipers are perfectly centered on the rotor, everything went together perfectly, the only customizing was the e brakes cables, I had to use a Lokar universal kit.
 
Before you do, remove the caliper and see if you've got any side (in and out) movement in the axle, the sound you're hearing could be the green bearings side loading. When you apply the brakes the piston pushes the disc, therefore the axle, out till it meets the outer pad (not much but it does). How old are the green bearings. This is why I like the Kelsey Hayes design on the front discs cuss that design squeezes the disc to stop.
 
Mad Dart said:
demon seed,

So what kit do you like for the Rear without breaking the bank?
Click to expand...

To be honest I've never entertained the idea of rear discs and A or B bodies, never had trouble with the big drums, but if I was I'd be looking at the Wilwood brakes which could yes "break the bank".
 
Just got off the phone with the guys at Right Stuff and they suggest that I check the mounting brackets so I will let you know what I find out.
 
Both brackets that mount to the axle housing are bent! Nice! How did that happen? Right Stuff is sending me new ones. Yeah!
 
Well I got the new brackets from Right Stuff on Monday, they sent them no charge which was cool. I installed them yesterday and used shims to space the brackets out a little but still hold the axles in firmy and "Voila" no more noise! I am also running the proportioning valve wide open and the car stops great! VERY HAPPY NOW! I have to commend the tech guys at Right Stuff for helping me figure out what was going on and they are going to address the issue with either providing shims or machining a small groove in the bracket. The company is top notch and the best bang for the buck when it comes to doing a drum to disc swap. Thank you to all who put up with my whinning, you would think that at 40 yrs old I would quit that! Hahahaha. Check out the newest issue of Car Craft magazine for a whole write up on the Hotchkis Suspension setup installed on my Valiant! I am going to drive the car to Orange County this weekend and enter it in an autocross event, hopefully beat up on some imports!
 
I just put the same Right Stuff rear kit on my cuda last night and it was easy. Everything fit fine with the exception of the e-brake cables. The kit gives you 2 that are the same size, one is about 6 inches too long for the drivers side, and the other one is about 4 feet short for the passenger side. I will call them this week and see about some different cables and see what they say. So far, it looks like a quality kit. I picked mine up from the Indy Cyl Head show form Right Stuff at their booth. Really nice guys to deal with. My cuda won't be running for quite a while yet so I can't tell you how they work yet.
Question for you, what master cyl are you using? and did you remove the green bearing retainer plate like the instructions said to? I left mine on because it looked like the bearing would slide out if I did. I have some pics of the install that I will try to post sometime soon.
 
I am using the stock master cylinder for manual brakes and it stops great, yes I did remove the stock retainer plate, I am pretty sure you have to. I bought a universal Lokar e brake kit from Summit that worked great but you have to get creative with the right side cable because it was still too short, I added a piece of cable from the left side to get the right length. I will take some pics when I get a chance. The Right Stuff guys are the best to deal with for sure. Ditch the big block idea and build you a nice 408ci 360. You dont need the extra weight or the lack of room in the engine compartment.
 
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