Parking brake adjuster issue, two remanufactured calipers

[midnite03]

Hi all,
I have an 03 P5 with about 125k on it. I was noticing that the right rear brake rotor wouldn't ever get cleaned by the pad- the inner half of the swept area stayed rusty. Tried new rotor and pads with no help, changing the caliper fixed this original issue. (I think it was to do with too much corrosion on the caliper body, the way the pads were being held.) I got a reman right rear caliper from Rockauto, brand A1 cardone. I know how the calipers work, I have a Miata as well - as in using the allen wrench to back the pads off and then adjust up to the rotor, back off a little bit and the adjuster in the piston takes care of the final adjustment and through the life of the pads. The issue I am seeing is that the parking brake tension on that side is going away after the initial adjustment, not getting better. I got another caliper, this time a reman Wagner. In actuality, they seem to have come out of the same house- the presentation of the part, the extras included, and the packing are the same, it is just a different label on the box. Day 3 with the new new reman caliper, and the handbrake tension is going away again. With the A1 Cardone, I adjusted the brake back up after the first time and it happened again.
Two possibilities, one I am doing something wrong, 2 both calipers have the same defect. To be honest I am leaning to the second. It occured to me to swap parts off the original caliper (swap the adjuster mechanism over) and that is probably what I will try unless you guys can set me straight (or it gets better by itself which would surprise me greatly).
Thanks in advance for any thoughts you can provide on this...!

 

[P-Funk!]

It was my experience as well (just on the left/rear caliper).

The pin had seized so I installed the replacement caliper (NAPA) and it required constant adjustment to keep the parking brake function. Right side was fine. [rolls eyes]

So, no help from me other than "I feel your pain"...

 

[stivine6]

Wondering if this is common issue with the pro? I'm having the same problem with my pro although i know that the rr caliper is seized opened. But the left is fine but doesnt grab as well as i would like...

 

[Maroon]

Are the guide pins sliding okay? Is the parking brake cable moving freely?

I have never adjusted my rear calipers after a pad change. I back the pistons as far as they go, install pads and caliper, and let pressure do the adjusting.

It does sound like you got another bad caliper.

 

[midnite03]

Are the guide pins sliding okay? Is the parking brake cable moving freely?

I have never adjusted my rear calipers after a pad change. I back the pistons as far as they go, install pads and caliper, and let pressure do the adjusting.

It does sound like you got another bad caliper.

Thanks to all for your replies.

Yes, the pins and the cable are fine. I looked at the first new caliper (off the car now) last night, the piston was all the way retracted. I didn't touch the adjuster when I took it off, because there was no need to. I could still extend the piston with the adjuster. It makes me wonder whether there is a left and right handed adjuster and if you mix them up in the rebuild, the self-adjust loosens rather than tightens. I did not have this issue with the old caliper (different issue with the pad body as I mentioned). It would be bad luck to get two bad in a row anyway, even if this is the explanation.

I will report back on how this works out and look out for any more suggestions. I am thinking of trying to swap the adjuster (which is in the piston). I could swap the whole piston (which would be easier) but I prefer to have the piston that was checked out during the rebuild. I am not sure how critical that would be actually. The piston seal is fit to the caliper body, not an o-ring on the piston (in case anyone was in doubt).

 

[TheSwapnessMonster]

I've had this problem at least twice. It's common for proteges. I have successfully taken the adjuster screw out of one rear caliper to use in the other.