caliper rebuild questions

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09-22-2009, 09:03 AM
nealb

caliper rebuild questions

I got 1994 brakes to put on my 1993 for a cheapo bigger brake setup

want to rebuild the calipers, so I get all the seal and hardware stuff from mazdaspeed

but, the caliper pistons won't pop out of the bores

tried pulling the outside boots and putting 120 psi air pressure into the brake line hole, but the calipers just move out a bit and won't budge

don't want to scar them up prying, so does anyone know "the trick" ?

looked on miata dot net in the garage section, but didn't see this kind of how-to
09-22-2009, 09:20 AM
POS Racing

Last ones I did just needed a "touch" of air and the pistons came out easy.

Is the piston square with the boar or is it hung in the boar??
09-22-2009, 09:42 AM
nealb

looks square

tried two calipers and 140 psi and slip joint pliers to twist and pull

no luck
09-22-2009, 09:46 AM
POS Racing

Yikes!

We are taking the front calipers?
09-22-2009, 09:50 AM
nealb

tried the rear first, haven't touched the fronts yet
09-22-2009, 10:05 AM
POS Racing

Quote:

Originally Posted by nealb

tried the rear first, haven't touched the fronts yet

Rears are a totally different animal!

Fronts are cake! But I buy rebuilt for the rear... YMMV
09-22-2009, 10:08 AM
POS Racing

Did ya did find this in your searching -> http://www.bigllama.com/miata/brake/bigbrake.htm

And this is good stuff on the rears -> http://www.miata.net/garage/ebrake/index.html
09-22-2009, 10:16 AM
jrj512

I rebuilt mine last winter. The fronts were easy. The rears are tough, so I just bought rebuilt calipers.
09-22-2009, 10:23 AM
ken o

Don't the have a screw connected to a worm gear on the rears?
09-22-2009, 11:08 AM
nealb

Quote:

Originally Posted by ken o

Don't the have a screw connected to a worm gear on the rears?

the 90-93 does, but I didn't see the same setup on the 94-97 that I got
09-22-2009, 11:12 AM
POS Racing

Quote:

Originally Posted by nealb

the 90-93 does, but I didn't see the same setup on the 94-97 that I got

They should be the same!

My '94 has the adjuster screw and so does my wife's '02.
09-22-2009, 11:19 AM
Titus

He has the brakes off of my '96M parts car (formally Chucka's car). They should have the same adjuster screw that all the rest have.
09-22-2009, 11:26 AM
POS Racing

From Mazdaspeed:

1991 Miata Rear Calipers
Caliper Assembly (R) NA01–26–980A Rear <A> NAY1-26-98ZR
Caliper Assembly (L) NA01–26–990A Rear <A> NAY1-26-99ZR

1993 Miata Rear Calipers
Caliper Assembly (R) NA01–26–980A Rear <A> NAY1-26-98ZR
Caliper Assembly (L) NA01–26–990A Rear <A> NAY1-26-99ZR

1994 Miata Rear Caliper
Caliper Assembly (R) NAY5–26–98ZR Rear
Caliper Assembly (L) NAY5–26–99ZR Rear

1997 Miata rear Caliper
Caliper Assembly (R) NAY5–26–98ZR Rear
Caliper Assembly (L) NAY5–26–99ZR Rear

Notice they are the exact same p/n.
09-22-2009, 01:47 PM
nealb

and the 94+ rear does have the hex adjuster screw thingie, duh

the rears took more than an hour each and were a PITA

fronts about 15 min each

glad that's done
09-22-2009, 01:51 PM
nealb

Quote:

Originally Posted by POS Racing

From Mazdaspeed:

1991 Miata Rear Calipers
Caliper Assembly (R) NA01–26–980A Rear <A> NAY1-26-98ZR
Caliper Assembly (L) NA01–26–990A Rear <A> NAY1-26-99ZR

1993 Miata Rear Calipers
Caliper Assembly (R) NA01–26–980A Rear <A> NAY1-26-98ZR
Caliper Assembly (L) NA01–26–990A Rear <A> NAY1-26-99ZR

1994 Miata Rear Caliper
Caliper Assembly (R) NAY5–26–98ZR Rear
Caliper Assembly (L) NAY5–26–99ZR Rear

1997 Miata rear Caliper
Caliper Assembly (R) NAY5–26–98ZR Rear
Caliper Assembly (L) NAY5–26–99ZR Rear

Notice they are the exact same p/n.

the 1994 and 1997 are the same

earlier # looks different to me -- NAY1 instead of NAY5

am I missing something (else) ?

could I have just bolted my OEM 1993 rear calipers to the 1994 brackets ?

have to look at the tech info and see

I see the rear brake pad # are different for 90-93 versus 94+ even tho when I put them side by side they look the same
09-22-2009, 03:10 PM
creek

All you need are the brackets and rotors. You can keep your calipers. I guess you have spares now.
09-22-2009, 03:14 PM
ken o

Quote:

Originally Posted by nealb

and the 94+ rear does have the hex adjuster screw thingie, duh

the rears took more than an hour each and were a PITA

fronts about 15 min each

glad that's done

Was it the screw?
09-22-2009, 03:56 PM
nealb

Quote:

Originally Posted by ken o

Was it the screw?

getting the pistons into the dust boot

needs more than two hands

and the screws and the snap ring thing
09-22-2009, 06:21 PM
POS Racing

Quote:

Originally Posted by nealb

could I have just bolted my OEM 1993 rear calipers to the 1994 brackets ?

Did you look at this -> http://www.bigllama.com/miata/brake/bigbrake.htm ;)
09-23-2009, 07:38 AM
nealb

Quote:

Originally Posted by POS Racing

Did you look at this -> http://www.bigllama.com/miata/brake/bigbrake.htm ;)

yes but this doesn't mention rears at all

I wanted fresh calipers anyway to replace 125,000 mile units (may be less, but don't know the history of the car)

and for sure the 1.6 rear pads will not fit the 1.8 rear caliper bracket

I compared new 1.6 rear pads to old 1.8 rear pads on the bracket

haven't looked at the front but the write up says they are different
12-19-2009, 01:17 PM
jeepinbanditrider

Is there a write up somewhere on how to rebuild the fronts. Seems straight forward. Just pull the piston and replace the seals.
12-19-2009, 03:37 PM
Titus

Quote:

Originally Posted by jeepinbanditrider

Is there a write up somewhere on how to rebuild the fronts. Seems straight forward. Just pull the piston and replace the seals.

I did it without instructions, and I had never done a caliper rebuild before. It is simple enough. It used the air compressor to shoot the piston out. That said, next time I will just buy a rebuilt caliper, as the price difference between the rebuild kit and the rebuilt caliper doesn't seem big enough to warrant the work.
12-19-2009, 04:23 PM
jeepinbanditrider

I dunno its about 20 bucks for a kit that will do both sides. Cheapest I could find rebuilt calipers for is 36 dollars a piece after I turn the cores in. I'm tempted to go that route just to have a fully rebuilt caliper but at half cost it's hard to beat lol.
12-19-2009, 04:32 PM
Titus

Quote:

Originally Posted by jeepinbanditrider

I dunno its about 20 bucks for a kit that will do both sides. Cheapest I could find rebuilt calipers for is 36 dollars a piece after I turn the cores in. I'm tempted to go that route just to have a fully rebuilt caliper but at half cost it's hard to beat lol.

Keep in mine that there is a chance you will get the calipers apart and find that the piston is pitted. It is my understanding that you are SOL if this is the case. Then you still have to put it back together to use as a core on the new caliper, and have found yourself paying for a caliper on top of the bag of seals that you no longer need. YMMV
12-19-2009, 08:39 PM
jeepinbanditrider

True. You can hone out the caliper but for that much effort I'd just get the refurbs.