rear brake calipers.....MOT WOES

For all technical questions. VIEWABLE without login, you need to register (free) to be able to post a question.
el plates
Full Member
Posts: 190
Joined: Thu Sep 06, 2018 9:24 pm

Re: rear brake calipers.....MOT WOES

Post by el plates » Sat Oct 24, 2020 11:21 pm

OK,

sorry has taken an age to get this sorted.

But now MOT'd and good.

ended up buying another probe and swapping the caliper off that.
(yes you did hear that right).... lol lol

Not ideal as i still have a caliper problem but now just on the donor car....

But i am now on the road and can get to work.
and i have the time to source and test other calipers in my parts store....
to get the donor back on the road.

working through them as we speak.

putting them on and taking the car to the garage for the rolling road test.

three tested three failed..... so far
(and this is on a different car to the original car that failed the MOT on the rear pass caliper....)


So here's a question:
and i think that i asked it some time ago, but cant remember the response.....

I have the Mazda front caliper, rotor, and pad upgrade.

but is there a rear upgrade that might get past this rear caliper issue???

any answers gratefully received.

:)

jrh
Full Member
Posts: 507
Joined: Thu Sep 20, 2018 3:08 pm
Been thanked: 14 times

Re: rear brake calipers.....MOT WOES

Post by jrh » Sun Oct 25, 2020 8:50 am

The Sherlock Holmes way, eliminate what is working well and you are left with............what isn't.
So, using the foot brake, everything was ok ?
YES , eliminates pads and disc and hydraulics , they are ok.
So, it is purely a 'mechanical' problem.
As said, the way the movement of 'pull' ( handbrake cable ) , to' turn' ( spindle which goes into caliper ) , then 'push' ( mechanical adjustment screw -the one you adjust ) to the brake piston is the work of an evil genius.
If you have ever managed to deconstruct the caliper down to it's component parts you have achieved ' Grand Master' status of Zen Brake Parts.
The spindle lip seal leaks, salt water rusts the spindle and bore it turns in, clean it all up and it is still useless because of too much 'slop' everywhere.
Proper adjustment and free working not possible.
I really wonder what they do with these 'refurbished calipers.
Re-sleeving spindle bore and fitting oversize spindle minimum, but do they ?
If there is the slightest shake or movement in those components it is 'doomed'.
You will have seen that you only have less than 1/4 turn of 'push' available on that adjusting screw between handbrake off and fully on.
Maximum 'push' is at 90 deg .
It really needs to be solid contact between disc and pad at 80 to 85deg ie max torque . 0deg would exert 0 torque no matter how hard you pulled the handbrake.
IF you get contact earlier than that , maximum pressure WILL NOT be applied to the piston/pads.
Maybe that is what is happening in your case .
'

el plates
Full Member
Posts: 190
Joined: Thu Sep 06, 2018 9:24 pm

Re: rear brake calipers.....MOT WOES

Post by el plates » Wed Oct 28, 2020 7:11 am

WOW,

Many thanks there's an answer and a half... lol lol

So bottom line old calipers once past it are difficult if neigh on impossible to easily refurb....

Many thanks
-----------------------------------------------


So back to my second question:


is there a rear upgrade (like the front mazda upgrade) that might get past this rear caliper issue???

any answers gratefully received.

Micron
Site Admin
Posts: 1091
Joined: Thu Sep 06, 2018 6:08 pm
Been thanked: 9 times

Re: rear brake calipers.....MOT WOES

Post by Micron » Wed Oct 28, 2020 8:00 am

el plates wrote:
Wed Oct 28, 2020 7:11 am

-----------------------------------------------


So back to my second question:


is there a rear upgrade (like the front mazda upgrade) that might get past this rear caliper issue???

any answers gratefully received.
Wayne,

I would think that the issue you will have is trying to get something mounted on to the hub, the calliper bracket is going to be the issue and once that has been done the hand brake.
Have you asked on any of the US Facebook sites, as they do a lot more things to their cars than we ever do, being British and all that :lol: :lol: (Apart from Jon G, he's always doing stuff :lol: :lol: )

Kit
Tech Rep
Posts: 1267
Joined: Fri Sep 07, 2018 8:16 pm
Has thanked: 14 times
Been thanked: 17 times

Re: rear brake calipers.....MOT WOES

Post by Kit » Wed Oct 28, 2020 3:09 pm

The late Mazda 625, does have a similar rear calliper, but different ( like I found out).
The body & mounting the Sam, but the pads are different, there’s not adjustment screw, so you need the wind back the cylinder when you put new pads in. The action of the handbrake, keeps them adjusted

So, this might be worth looking into

Kit

cpt black
Tech Rep
Posts: 1021
Joined: Fri Sep 07, 2018 8:28 am
Has thanked: 1 time
Been thanked: 12 times

Re: rear brake calipers.....MOT WOES

Post by cpt black » Wed Oct 28, 2020 4:45 pm

Believe i have 2 brand new OEM 626 Calipers surprise surprise :lol:

Micron
Site Admin
Posts: 1091
Joined: Thu Sep 06, 2018 6:08 pm
Been thanked: 9 times

Re: rear brake calipers.....MOT WOES

Post by Micron » Wed Oct 28, 2020 5:16 pm

I was looking at Mazda 6 rear brakes earlier, but not sure if the mounting bracket would fit, or if you need different discs because they are larger?
Would need to measure both to see?
The actual operation of them looks the same?

Kit
Tech Rep
Posts: 1267
Joined: Fri Sep 07, 2018 8:16 pm
Has thanked: 14 times
Been thanked: 17 times

Re: rear brake calipers.....MOT WOES

Post by Kit » Wed Oct 28, 2020 5:31 pm

Micron wrote:
Wed Oct 28, 2020 5:16 pm
I was looking at Mazda 6 rear brakes earlier, but not sure if the mounting bracket would fit, or if you need different discs because they are larger?
Would need to measure both to see?
The actual operation of them looks the same?
Any one with a Mazda 6 in the club :?:
That could take a look & compared ;)

Kit

Incognito
Full Member
Posts: 1082
Joined: Thu Sep 06, 2018 9:27 pm
Has thanked: 8 times
Been thanked: 1 time

Re: rear brake calipers.....MOT WOES

Post by Incognito » Wed Oct 28, 2020 6:09 pm

Kit wrote:
Wed Oct 28, 2020 5:31 pm
Micron wrote:
Wed Oct 28, 2020 5:16 pm
I was looking at Mazda 6 rear brakes earlier, but not sure if the mounting bracket would fit, or if you need different discs because they are larger?
Would need to measure both to see?
The actual operation of them looks the same?
Any one with a Mazda 6 in the club :?:
That could take a look & compared ;)

Kit
John , JRH.

Micron
Site Admin
Posts: 1091
Joined: Thu Sep 06, 2018 6:08 pm
Been thanked: 9 times

Re: rear brake calipers.....MOT WOES

Post by Micron » Wed Oct 28, 2020 6:16 pm

Incognito wrote:
Wed Oct 28, 2020 6:09 pm
Kit wrote:
Wed Oct 28, 2020 5:31 pm
Micron wrote:
Wed Oct 28, 2020 5:16 pm
I was looking at Mazda 6 rear brakes earlier, but not sure if the mounting bracket would fit, or if you need different discs because they are larger?
Would need to measure both to see?
The actual operation of them looks the same?
Any one with a Mazda 6 in the club :?:
That could take a look & compared ;)

Kit
John , JRH.
Now why didn't we think of that 🤔🤣🤣🤣

Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 12 guests