Does anyone know of a reason not to replace the lower pin, the one with the rubber on it, with a solid one like the upper?
Less rubber to swell up and hinder movement.

Track only use, don't care about street manors.

 

I had constant issues with the rubber on the lower bushed pin swelling and binding the caliper slider. I replaced the lowers with another set of upper bolts about 4 track days ago with no issues.

I tried everything before going this route. A lot of moly based brake lubricants will have ceramics and silicone stuff that will cause rubber to swell. Even one's that list as safe for rubbers were causing issues. At any rate, I sourced some replacements from rock auto as they were much cheaper than the ones on mazdamotorsports and/or through a dealer source.

 

Thanks EE,
I replaced them with a set from NAPA. We will see how they feel. Just updated the fronts from NA8, so the feel should be differant from what I had.

Like you I have tried every lube listed "safe for rubber" and they all failed. At least now the only rubber is the small boot and it can't cause the caliper to stick.

 

Track only? Why no wilwood caliper replacement yet?

 

"Because TTD"

 

Is this a sport only thing? If I had a lathe I would have made my own bronze bushing's to replace the rubber on the front calipers by now. But if the big pin works in the little pin's spot on non-sport brakes thats even easier.

 

this is a great idea. my rubbers keep swelling too, causing issues. this is happening next time i have brakes apart.

 

Been running them like that for 4 years now. No problemo.

 

Doesnt work. The thread sizes are different, the big pin doesnt even fit through the thread. You'd need a pin like the one under the green cap on the rear calipers for this to work.