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-   -   Stock front FD calipers -- source (https://www.rx7club.com/race-car-tech-103/stock-front-fd-calipers-source-907550/)

AMRX7 06-07-10 01:04 PM

Stock front FD calipers -- source
 
Any one know a good source for good condition stock front calipers? I'm getting alot of flex in the brakes and am fairly sure that 15+ yrs of hard autocrossing has fatigued mine. Very uneven wear on the pads front to back, so something is moving around and I don't think it is the spindle.

Motorsports doesn't have any new stock calipers, they'd have to order from Japan. Any ideas on where to get replacements? I need to sick with stock given other clearance and modification issues with my setup.

Thanks,

Andy

AMRX7 06-07-10 01:11 PM

Nevermind. Fritz on the hookup.

As a secondary question, has anyone else seen this type of issue? Where pads are wearing much more on the leading edge vs. trailing?

-Andy

gkmccready 06-07-10 03:00 PM

We see the pad taper issue on the slide rail calipers on C5 and C6 Corvettes all the time. There're a couple of reason for it, one is caliper flex/spread issues, and the other is the brake piston sizing. You'll see most aftermarket calipers have pistons of different bore sizes to try to eliminate the latter, the former is just a fact of life as time goes on.

AMRX7 06-07-10 03:42 PM

That's the same feedback I got from some other sources as well. My car only does autocrosses, but it's seen 15 years of hard stops with big sticky rubber. Hopefully some less abused calipers do the trick.

-Andy

Gene 06-07-10 05:32 PM

You can get away with flipping the pads from side to side to counter the taper wear as long as you do it before they're too badly worn.

gracer7-rx7 06-07-10 06:08 PM

Neither Mazda Comp nor Ray have new stock front or rear calipers anymore. I replaced a rear last year and sourced it from the local NAPA.

I recently bought front calipers for my Miata and received a reman unit from Mazda Comp and a brand new one from a dealer in Louisiana or Mississippi. So not much availability of new parts on those cars either. Time to start hoarding brake parts. :)

j9fd3s 06-07-10 06:26 PM

want to know how many FC/FD calipers we sold in the 10 years i worked at the dealerships? zero.

rear miata calipers we used to stock though. occasionally someone would muck up a front too, but in CA, with no salted roads, calipers last forever.

although i did rebuild a set of really really abused FD calipers for an FC, the pads actually got hot enough to melt the pistons.

Japan2LA 06-07-10 06:31 PM

I have PLENTY of Low mile Used Jspec calipers

I can do pairs in the $65.00 Shipped range

All with less than 30,000 miles

Front and rears...

Did I already say I have Plenty?

dgeesaman 06-08-10 09:02 PM

The stock calipers are made of aluminum. Fatigue, technically speaking is the spread of cracks. If there was fatigue taking place the cracks would quickly accelerate and lead to significant breakage.

You might want to check the torque of the bolts that hold the calipers together.

Are you using low coefficient pad to help with pedal feel? While low friction pads help feel they can increase piston force and caliper deflection.

Dave

AMRX7 06-08-10 10:58 PM


Originally Posted by dgeesaman (Post 10046421)
The stock calipers are made of aluminum. Fatigue, technically speaking is the spread of cracks. If there was fatigue taking place the cracks would quickly accelerate and lead to significant breakage.

You might want to check the torque of the bolts that hold the calipers together.

Are you using low coefficient pad to help with pedal feel? While low friction pads help feel they can increase piston force and caliper deflection.

Dave

I actually did check the caliper bolts and they were all very tight. One thing I had noticed for quite some time though is that when bleeding and someone was pumping the brakes, there would be alot of creaking noises from both front calipers. Some of that was probably due to the pads uneven wear, but in retrospect probably due to other issues as well. I'll take a close look at the calipers for any visible problems when I take them off.

And I've used pretty high friction pads for years.

-Andy

dgeesaman 06-09-10 05:10 AM

Eh, just fishing for ideas. The cost of replacements from Japan2La is so reasonable you might as well change them and see if it helps.

Japan2LA 06-09-10 07:52 PM


Originally Posted by dgeesaman (Post 10046945)
eh, just fishing for ideas. The cost of replacements from japan2la is so reasonable you might as well change them and see if it helps.

+1

billyboy 06-12-10 06:39 PM

The S4/5 calipers are well known over here as going soft over time after repeated heat exposure - this is pulling up say 2200lb race cars. S6+ calipers are probably in the same category....and you've got more weight.

I'd caution about giving a tweak to the caliper bridge bolts, as there's no torque spec and I wouldn't be surprised they're a measured stretch type. As an aside, bought a set of RZ/RS brakes off a knucklehead on here, who'd disassembled the calipers to paint them. After a couple of thousand km of rally use, had complete loss of brakes after the bolts backed off....and was shocked to see the join line had a couple of mm of light visible between the halves.


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