Callipers leaking 6 months after rebuild

Luke · Postby **Luke** » Sat Dec 10, 2016 9:23 pm

Regarding pads moving up and down plus rattles, check if you still have your pads spring clips or that they are not broken.
I have lost a few over the years on track as they fatigue.
Mazda Australia do not sell them, neither does Amayama.
MX-5 Mania never have stock each time I ask.
You can get them from the States from various vendors.

My brakes have probably been abused more than yours have over the years.
My Dad and I rebuilt the front callipers for first time at the beginning of this year.
We changed everything except for the pistons with all genuine Mazda parts.
My dust seals were missing chunks and were crispy.
The inner ones were still good.
Not a single issue after 7 Supersprints, 3 Marulan days and 3 Motorkhanas.

I have had DBA rotors in the past and have burnt off all 3 colours.
No calliper issues. Have had the rotors crack though.
I'm just going to have to go with that lower quality parts have been used for your rebuild or not put together correctly.

I did put Trackspeed ducts in 2.5 years ago.
Pads last longer and no more cracking rotors after 6-8 sprint rounds. Also stopped using DBA 4000 slotted rotors. Now use Protex plain el cheapo rotors at 1/3 of the cost.

I also noted you are using Carobotech XP10 pads.
Are you using DBA 4000 T3's with these.
A couple of us had bad experiences a couple of years ago with this combo specifically on NB8B brakes with T3 rotors only.
The pads just left an uneven transfer layer over the rotor and then you would get high frequency vibrations whilst braking.
Old thread here.
viewtopic.php?f=30&t=53747&p=678874#p678874

I have used both XP10 and XP12 successfully on plain Protex rotors.

Roadrunner · Postby **Roadrunner** » Sat Dec 10, 2016 11:12 pm

Hey Luke, I've been reading your thread from a few years ago already today. Will have a chat tomorrow at the supersprints as I remembered you have ducting. Want to get some ideas for routing the pipes on an SE.
All the spring clips are intact and in place.
Rotors are DBA HD vented plain faced rotors.

What you have experienced is basically what I've had, except my seals roasted where yours didn't and I haven't experienced any brake shudder where you did (plain faced vs slotted)
The common thing in both cases was extreme heat!

In fact the common thing in that thread which struck me was SE's, xp10s and extreme heat.

I'm not entirely convinced the rotors melted from track day abuse as I've never witnessed smoking rotors after a session but track day abuse does make sense.
Will pick up a temperature gun and measure temps after every drive for the next week or so and see if they are roasting after a trip to the shops.

Ruling out faulty master cylinder valve at the moment as if it was this I'd imagine all 4 brakes would be dragging and overheating not just the fronts.

Nevyn72 · Postby **Nevyn72** » Sun Dec 11, 2016 11:23 am

Roadrunner wrote:Now other than a possible mechanical issue with the brake system that wasn't there (or apparent) before the rebuild, the only other thing that I can think of that has changed is the ducting I have done for the radiator.
I'm wondering if closing off the front bumper opening to just the radiator has scavenged air that would normally flow out the side to the rotors?

I suspect this is the cause of your excessive heat issues.... :wink:

Solution? -> Remove fog lights, install brake cooling ducts! :mrgreen:

Roadrunner · Postby **Roadrunner** » Sun Dec 11, 2016 4:00 pm

i was thinking that this morning, but I did a Wakefield day after the ducting but before the calliper rebuild and didn't have this issue.
Taking to a few people at the track today and getting thoughts and opinions and I think it's looking more and more like a bad rebuilt job or poor quality parts used, but have a few things to check first.

Tony · Postby **Tony** » Sun Dec 11, 2016 4:24 pm

Roadrunner wrote:a bad rebuilt job or poor quality parts used

More than likely that is all it will be. Use genuine parts only and rebuild again.

Don't overthink it.

Roadrunner · Postby **Roadrunner** » Mon Dec 12, 2016 1:07 pm

Do you think the heat could have damaged the caliper body?
And where can I get genuine rebuild kits from? A few build places are saying its aftermarket options only now?

Roadrunner · Postby **Roadrunner** » Mon Dec 12, 2016 3:44 pm

It's dead:
I'm just glad I discovered this before the track day on Sunday. Would hate to have gone into turn 2 or turn 10 with no brakes if the seal completely let go :shock:

Magpie · Postby **Magpie** » Mon Dec 12, 2016 4:49 pm

I doubt that the body of the caliper would be 'damaged' by heat. Before the caliper body itself was damaged rubber would melt, fluid would boil, hoses would burst and guess what next...

Warm up lap on the first practice run at WTAC 2016 (Thursday). This car caught fire when brake line failed

IMG_4772 by Eipeip, on Flickr

This is on the Friday of WTAC when the session was cut short and I could not do a warm down lap. I used my blower fan to cool down the brakes.

Consider that heat moves to colder areas. Therefore the heat from the rotors goes to the pads, the pads in turn heat up the calipers and the calipers heats up the brake fluid. Each part in the brakes has a maximum thermal capacity and once this is reached things start to fall apart. In the whole brake circuit the fluid is the item that cannot take heat. With my caliper at about 230°c there was a risk that the brake fluid had been pushed to it heat limits. If the brake fluid boils then the lines would have to be bled or even replaced. Also, brake fluid is hygroscopic and any moisture lowers its boiling point hence needs to be changed even more frequently if tracked (or abused).

The paint used on the DBA rotors is single use and shows the max temp reached. It needs to be replaced if you want to track the temperature of the rotors.

DSCN3500 by Eipeip, on Flickr

As said previously, get some temp strips and some heat paint and see what is happening down there.
http://www.racerindustries.com.au/afawcs0161690/CATID=80/ID=13487/SID=22324332/Racetech-Thermal-Paint-Indicator-Kit.html
http://www.racerindustries.com.au/afawcs0161690/CATID=80/ID=1165/SID=22324332/Thermal-Indicating-Temperature-Strips-10-Pack.html

Roadrunner · Postby **Roadrunner** » Tue Dec 13, 2016 5:08 pm

I'll order the heat strips tonight. Thanks :wink:

Luke · Postby **Luke** » Wed Dec 14, 2016 12:01 pm

I was about to say Amayama but just noticed when you look up the part number it now says Non-original replacement.
Oddly the part is still listed as made by Mazda with the same part number.
This is really strange because RX-8s and NC's use the same caliper rebuild kit as NB8B's.

This is the part number for the seal kit:
B2YD-33-26Z
It includes, 2 Caliper Seals, 2 Dust Seals, 2 Brake Bleeder Rubber Caps, 4 Slide Pin Rubber Seal Boots and some assembly goop.
I ordered my seal kit early this year and they were original back then in Mazda Packaging.
As a reference, Mazda AUS wanted $143.20 when I quoted them, Amayama was $39.44.

At the same time if you already didn't change these before you may as well purchase 4 new slide pins. They are about $9 a spin.
2x B25D-33-998
2x B25D-33-694
As well as 4 New Slide Pins Bolts. They are about $4 each.
4x B25D-33-698

I ordered this plus some other bits and pieces. The total shipped price was only $8 more than the sum of all parts. No idea how they did that from Japan.

Priority Mazda in the States still lists the B2YD-33-26Z kit. $36.70 USD.
Does not say if it original or not, you would have to ask them.
I have never needed to deal with them so far but they are supposed to be the Arlington Mazda Replacement since they shutdown shop. They have Mazda Diagrams on their site when you look up parts.

If you do go with Priority Mazda you may as well order N0Y7-33-29Z-MV as well. These are the front brakes clips for NB8B brakes which are a bit difficult to purchase locally.

Roadrunner · Postby **Roadrunner** » Wed Dec 14, 2016 3:47 pm

Thanks Luke!

manga_blue · Postby **manga_blue** » Wed Dec 14, 2016 4:15 pm

Mx5parts.co.uk sell the front seal kits for $41 per corner for standard brakes or $23 per corner for big brakes if you're in more of a hurry. I bought fronts and rears from them 2 or 3 years back and they were all genuine Mazda Made in Japan then.

http://www.mx5parts.co.uk/front-caliper-seal-mk1-25-standard-brake-p-304.html?currency=AUD

http://www.mx5parts.co.uk/front-caliper-seal-mk25-brake-p-2915.html

Amayama is better if you can wait but there's the whole process with them of requesting a quote, receiving a quote, accepting the quote, paying the invoice before they ship and then it takes about 2 weeks after that.

One thing about mx5parts is that you can Skype them and talk to someone who'll look at the packet for you.

Tony · Postby **Tony** » Wed Dec 14, 2016 5:18 pm

Luke wrote:I was about to say Amayama but just noticed when you look up the part number it now says Non-original replacement.

You should look at the Amayama page again Luke; it's not obvious upon first glance but OEM is still available ex UAE.

Luke · Postby **Luke** » Wed Dec 14, 2016 8:53 pm

Tony wrote:
Luke wrote:I was about to say Amayama but just noticed when you look up the part number it now says Non-original replacement.

You should look at the Amayama page again Luke; it's not obvious upon first glance but OEM is still available ex UAE.

My bad, I definitely should look again and again just to be sure. I can't read.
I misread the non original replacement section as being part of the Mazda genuine parts section. No wonder it seemed off to have the original part number and made by Mazda.
Non original replacement is the heading for the parts below Mazda Genuine such as Pitwork and Febest. DOH!!!

So I stand corrected, Amayama Japan, Australia and UAE all stock original Mazda seal kits.

Roadrunner · Postby **Roadrunner** » Wed Jan 18, 2017 3:26 pm

Just to follow up on this, I managed to find a decent set of low km calipers including pins and brackets etc so just swapped them straight over with new rotors and pads.
I'll post up photos later of the drivers side caliper too now it's off the car, it's just as melted if not more than the passenger side.
So both fronts have seriously overheated at the same time at some stage since the rebuild.
Still not totally convinced this happened at the track as I experienced zero brake or fluid fade.
Perhaps it melted just enough during a session to then slightly drag on the way home and melted everything on the freeway when I never pressed the brake pedal for hours.

Anyway, new gear installed, brakes XP12 bedded then a good cool down drive on the freeway. During bedding rotor face got to 260degs and then cooled to 40degs after the cool down drive so they aren't dragging significantly.
All looks good. Let's see how they go at sandown this weekend.
Have also installed temp strips on the Calipers to keep an eye after each session.

I can hear the pads touching the rotors slightly at very low speed but there doesn't seem to be any heat buildup after a drive so hopefully it's just the close clearances. Googling seems to suggest this disappears after a bit of pad wear down and is normal?
The wheels spin freely but not as freely as the NB I have in the garage (spinning hard by hand gets about 5 or so revolutions but stops about 2 revolutions short of the NB which doesn't seem to touch the rotors at all)