Rear Disc Brake Help

[GTOConno]

Hello,
I am assembling the rear brakes and have a slight problem with the location of the caliper. This is a GM 10 bolt with new moser axles, '79 Trans Am rotors, mid 80's Cadillac calipers and Steeltech brackets. It seems that the caliper is located too far in to fit the outside brake pad. I think I have everything right but I'm not sure.
Please check the pics in the link, they will explain the problem.

Any ideas??

Thanks,
Conno


http://www.cardomain.com/ride/2314745/6

[nowukno]

You may need to use spacers to move the caliper out a little if you haven't tried that already..

[GTOConno]

Where would the spacers go? The caliper doesn't look like it can move out any further, and the bracket is limited by the axle flange.

Thanks,
Conno

[yellowrallys]

Looking at the photo, looks like the rotor is not slid up onto the axle far enough. Is the inside of the rotor contacting the O.D. of the axle before it's seating against the axle flange? Some axles need to have the O.D.s turned down in order for the rotors to fit correctly.

[nowukno]

Looking at the photo, looks like the rotor is not slid up onto the axle far enough. Is the inside of the rotor contacting the O.D. of the axle before it's seating against the axle flange? Some axles need to have the O.D.s turned down in order for the rotors to fit correctly.

This is a true statement!! try this also see if you can mount the bracket on the outer part of the axle flange without the same interference.

[Skip Fix]

The Moser axles do not have as long a pilot as the stock axles. Mine also barely protrude out of the rotors. I told them I was using the factory rear dsic setup and my factory brackets line up fine.

There mat be a difference that Moser made for the actual flange distance. I want to think years ago when the Pontiac guys at HO Racing had a kit for A bodies they use a spacer between the bracket and the flange on the tubes.

[GTOConno]

Thanks for the replies, the rotors are snugged up to the face of the axle flange, but I will double check that. I told Moser that I was using T/A disc brakes on them when I ordered the axles.

Also I checked the distance from the face of the axle flange to the face of the axle flange (out to out width) and it is the same as another rear I have in my shed.

I'll try mounting the brackets on the outside of the axle flange, but I think it will hit the rotor.

Does anyone make offset brackets?

Thanks again

[Skip Fix]

The factory brackets go outside the flange.

[Samckitt]

My first thought was the same as what Skip said above. do you have the bracket on the wrong side of the flange? I have rear discs from Baer on the back of the Monte & their brackets go on the outside.

Scot

[GTOConno]

Thanks, I'll try that tonight and see if that works.

Thanks again,
Conno

[GTOConno]

O.K. I tried the bracket on the outside of the flange and it doesn't work. It's too close to the rotor to put the caliper on. I think it works better on the inside of the flange but still not right.

I checked the rotors and they are tight to the face of the axle.

So I need to push the caliper out about 1/4" somehow.

Thanks,
Conno

[Skip Fix]

Be sure the OD of the axle is smaller than the ID of the rotors, I think some drum flanges were larger.

[critter]

I had no luck with the Steel Tech brackets. Didn't fit worth a dang. I finally bought some factory brackets, fabbed up a 1/4 inch aluminum spacer to fit between them and the axle flange and life was good.

[GTOConno]

Thanks Critter,
Will the stock TA brackets fit the cadillac calipers?

Oh, and the axles flanges were created for a rotor, I ordered them that way, so the rotors fit tight to the flange face.

Thanks,
Conno

[Chad-1stGen]

I bought a kit that uses those caddilac rotors and different brackets. The brackets are flat metal like yours and mount on the outward side of the axle flange. Unless you are using different rotors that sit further in you will need different brackets or a way to mount them on the outside of the flange.

[Chad-1stGen]

Just read your last post (right above mine). there is your problem. The rotor flange relationship is not stock so you need a custom setup...

In the end I went with the later model style calipers from touring classics and while they include spacers to get the adjustment correct their brackets also mount on the outside of the flange...

[Skip Fix]

Another thing to remember they are "floating" calipers and self center on the sleeves under the mounting bolts.

Here's a picture of the factory brackets and a Moser axle. They look offset but when tightened down have enough slide to center on the rotor.

[GTOConno]

O.K., I think I'm going to try and locate some Cadillac backing plates and see if that works.

By the way, I emailed Steeltech with this question and the pics when I first posted this thread and haven't heard back yet. Hmmmmm.

If anyone knows how to get a hold of those Cadillac backing plates could you let me know.

Thanks,
Conno

[ks71z28]

you need the rear drive 79 and later seville backing plates, 78 used a full size caliper body.

[GTOConno]

Thanks, do you know if the cadillac backing plate bolts to the outside face of the axle flange? I can shim it for fit if it does. So far I've found a place that sells them for $75 ea. Seems kind of steep.

Looking back I probably should have gone with a complete setup, like Touring Classics or the others. Oh well, live and learn.

Thanks again for all the help guys.
Conno

[Grandpa Ronsy]

I had a similar alignment problem down here in oz and we don't have the range of choices you Yanks have. My way out was to press the axle bearings off and machine the shoulder for the bearing closer to the flange and in your case that would be an 1/8" or so. There should be enough spline length to slip the axle in further. Of course this would not work if the axles are retained by circlips in the diff centre. In my case I machined the axles 1/4" and used a drop saw to shorten the splines. I'm running a 9" ford axle.

I just love doing things the hard way.

Grandpa Ronsy