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-   -   OPH Help Tweaking rear disc backing plates (https://forums.maxperformanceinc.com/forums/showthread.php?t=440636)

Skip Fix 02-10-2002 01:34 PM

OPH I know you have had to played with this. Just got my 12 bolt back form having ends welded, backing plates opened up, etc. Went to mock up the rear discs and teh drivers side has been tweaked. One side of the caliper is 0.2" further away then the other side. Been trying to use a cresent wrench to bend it but it seems to cock it at an angle . Seems like the base of the bracket needs some bend and its too stout there. Also bending one side separate may not keep the spacing perfect.

Any suggestions? I figure being a floating caliper it can have a little mis match but I remeber having one caliper squeal in reverse because the caliper was tweaked.

Skip Fix 02-10-2002 01:34 PM

OPH I know you have had to played with this. Just got my 12 bolt back form having ends welded, backing plates opened up, etc. Went to mock up the rear discs and teh drivers side has been tweaked. One side of the caliper is 0.2" further away then the other side. Been trying to use a cresent wrench to bend it but it seems to cock it at an angle . Seems like the base of the bracket needs some bend and its too stout there. Also bending one side separate may not keep the spacing perfect.

Any suggestions? I figure being a floating caliper it can have a little mis match but I remeber having one caliper squeal in reverse because the caliper was tweaked.

Tom Vaught 02-10-2002 05:41 PM

Skip, when they welded your housing ends on to the tubes, did they use a mandrel bar to make sure the ends were true to the axle centerline? Something smells here!! Tom

Skip Fix 02-11-2002 08:41 PM

Tom, Thye used a bar and ends were straight. The Drivers backing plate was used whne i got it an dhas some dings.

What finall worked after playing with it for hours was
1) bolt rotor on to axle for a reference
2) When using a cresent wrench to bend in the plate it cocks the bolt angle in too, when try to bend bolt hole back out palte moves out oot
3) After bending plate in then using a C clamp to hold most of plate up, then you can tweak bolt hole so it is straight. You can use a carpenters square also off the rotor to double check it.

As it is a floating caliper I'm sure it will "float" as it squeezes but I am not sure how "off" is tolerable for wear and squeal.

Tom Vaught 02-11-2002 09:09 PM

Skip, I was on a couple of brake sites over the weekend and they claimed for a fixed caliper .010
maximum to keep from pulling air past the seal. With a floating caliper, the spec can be a lot larger but might cause pistons to "work" more.
Maybe one of out brake experts will know as I am
interested in spec also Tom V.

'ol Pinion head 02-11-2002 09:23 PM

Skip,
I have been lucky but not run into this one... yet. Regret not getting back with you quicker.

Skip Fix 02-12-2002 02:50 PM

It took alot of tweaking and retweaking, and cussing! I also determined its been too long since I've been to the gym cause my arms were sore from it!Going to have to start pumping iron again.

'ol Pinion head 02-12-2002 02:55 PM

Skip,
How big a bore diam did you take the steel backing plate hole out to?

Skip Fix 02-13-2002 12:01 PM

Pyle Bros. did it . Looks just large enough to slip over the weld on ends. Maybe 3.150 as the dimension I rmemeber hearing from Moser. There was a special spacer that they also added from Moser, to help keep it centered it looks like. Moser knew exactly what they wanted and has them. I don't know why they didn't mention that when I ordered the axles and ends, as I said I was using the factory disc setup. They said they cut the flange diameter specifically for the factory rear discs.

What have you been using for brake lines on thses ? I only have one extra of the "blocks" that sandwiches with the copper gaskets that takes a plain flair line. Are you just adapting a "banjo" front caliper type fitting?


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