Jim
May 3rd, 2016, 10:15 PM
http://s7d9.scene7.com/is/image/GenuinePartsCompany/NWMDC?$Product=GenuinePartsCompany/930860
NAPA part number: CAL SE4689 (http://www.napaonline.com/napa/en/p/SEBSE4689/SEBSE4689_0248558257) (passenger side) & CAL SE4690 (http://www.napaonline.com/napa/en/p/SEBSE4690/SEBSE4690_0248558255) (driver side)
My 90 YJ rear axle has these "1982 Cadillac Eldorado" calipers on it. It seems they are fairly common on drum-to-disc conversions as they have an integrated parking brake system - a plus. The downside is they are unusual and not common and I'm hunting for "official" documentation.
Do you have any solid information on the operation or installation (bleed / adjust process) of them? I'd like to see factory print as all I've come to so far is "something posted on the Internet".
I am replacing both rear brake calipers. The driver's side installed and adjusted just as I have come to believe it should. The passenger side is proving quite problematic - as in - NAPA has, via their lifetime warranty, sourced the right side something like four times. We can't get a good right side caliper. I now "test them at the store" and if it fails the adjust test - they put it right back into the box and say they'll "get another one tomorrow". NAPA, I deal with Greg on this, is a nice guy but I'm getting tired of not getting a working caliper as he is likely getting tired of sourcing another caliper for me. He called his tech support on the issue and his support contacted their engineer - they agree with what I am saying - but I want more formal documentation/proof.
It is my belief (from "internet" research [which I desire to validate]) that the parking brake system is used to keep slack adjusted out of the pads - for these odd calipers. That the parking brake lever on the back of the caliper, when the parking brake system is activated, if the piston extends greater than 0.030", a one-way ratchet assembly inside of the caliper's piston will adjust the piston to take up slack from the pads as they wear.
It is due to this info that I, at the store, remove the parking brake return spring and run the parking brake lever through its full range of motion. Moving from at-rest to full-application, the piston extends outward from the caliper. On a good caliper, the piston should not retract to the original at-rest position - but should stay extended slightly - but noticeably enough by finger touch. On a "bad" caliper, the piston will retract to its original at-rest position.
It is my belief (from "internet" research [which I desire to validate]) that the driver needs to routinely use the parking brake to keep these calipers in proper adjustment.
It is my belief (from "internet" research [which I desire to validate]) that the re-builders might not test the one-way ratchet mechanism in the calipers. If this is true - and there is no real way to verify this - but at least I now test for piston actuation before leaving the store.
Anyone have experience with these calipers? Am I looking in the correct direction? Do you have any formal documentation to backup or refute my belief in these calipers?
Thanks,
Jim
NAPA part number: CAL SE4689 (http://www.napaonline.com/napa/en/p/SEBSE4689/SEBSE4689_0248558257) (passenger side) & CAL SE4690 (http://www.napaonline.com/napa/en/p/SEBSE4690/SEBSE4690_0248558255) (driver side)
My 90 YJ rear axle has these "1982 Cadillac Eldorado" calipers on it. It seems they are fairly common on drum-to-disc conversions as they have an integrated parking brake system - a plus. The downside is they are unusual and not common and I'm hunting for "official" documentation.
Do you have any solid information on the operation or installation (bleed / adjust process) of them? I'd like to see factory print as all I've come to so far is "something posted on the Internet".
I am replacing both rear brake calipers. The driver's side installed and adjusted just as I have come to believe it should. The passenger side is proving quite problematic - as in - NAPA has, via their lifetime warranty, sourced the right side something like four times. We can't get a good right side caliper. I now "test them at the store" and if it fails the adjust test - they put it right back into the box and say they'll "get another one tomorrow". NAPA, I deal with Greg on this, is a nice guy but I'm getting tired of not getting a working caliper as he is likely getting tired of sourcing another caliper for me. He called his tech support on the issue and his support contacted their engineer - they agree with what I am saying - but I want more formal documentation/proof.
It is my belief (from "internet" research [which I desire to validate]) that the parking brake system is used to keep slack adjusted out of the pads - for these odd calipers. That the parking brake lever on the back of the caliper, when the parking brake system is activated, if the piston extends greater than 0.030", a one-way ratchet assembly inside of the caliper's piston will adjust the piston to take up slack from the pads as they wear.
It is due to this info that I, at the store, remove the parking brake return spring and run the parking brake lever through its full range of motion. Moving from at-rest to full-application, the piston extends outward from the caliper. On a good caliper, the piston should not retract to the original at-rest position - but should stay extended slightly - but noticeably enough by finger touch. On a "bad" caliper, the piston will retract to its original at-rest position.
It is my belief (from "internet" research [which I desire to validate]) that the driver needs to routinely use the parking brake to keep these calipers in proper adjustment.
It is my belief (from "internet" research [which I desire to validate]) that the re-builders might not test the one-way ratchet mechanism in the calipers. If this is true - and there is no real way to verify this - but at least I now test for piston actuation before leaving the store.
Anyone have experience with these calipers? Am I looking in the correct direction? Do you have any formal documentation to backup or refute my belief in these calipers?
Thanks,
Jim