Toyota S12W caliper with Z31 vented disc, Brake conversion

atomman

Club Member
I'm not sure what the fixing hole PCD should be, does anybody have any advise? I don't think it's the same (114.3) and the wheel fixings.

Your right its not the same PDC as the wheel (114.3) it's smaller , also those 250mm disc's are probably the rears,
 

Peato40

Well-Known Forum User
Thanks @atomman, I clicked on the link and now there appears to be 2 x discs available, so I have just purchased them as they are already tried and tested by @toopy

Does anybody have any advice about the master cylinder ..... does it need to be upgraded to cater for these bigger calipers?
 

toopy

Club Member
Does anybody have any advice about the master cylinder ..... does it need to be upgraded to cater for these bigger calipers?

In a word...No, it may soften the pedal feel a tad, but a few months back i drove AliK's car, with these calipers fitted on the OEM master, and the pedal feel was absolutely fine, it actually felt no different to me, and the hard braking test i did (sorry Ali) was an eye opener in a good way ;)
 

Peato40

Well-Known Forum User
Thanks @toopy ..... I'm looking forward to getting mine completed and hard braking test of my own.

So I think I just need spacers now, is this something you have available for sale @atomman? or do I need to source from the US?
 

Breakzero

Active Forum User
OK So we are all now ordering the
BENDIX PRT1313. I just don't want the wrongs ones again.
That also makes sense @atomman they mount differently to any brakes i'm used to so. that explains the 4x103mm thing.
 

Peato40

Well-Known Forum User
Raybestos 9842R specification looks to be correct and is what I was initially going to buy but then I decided upon the Bendix PRT1313 because they are already tried and tested by toopy
 

johnymd

Club Member
I went for the stoptech dimpled and slotted disc's and better pads plus some good braided hoses. This puts the cost to around £500 which is exactly how much the silverline kit comes to without shipping and duty. If you can get them shipped over cheaply then its an easier option IMO.
 

johnymd

Club Member
I tried to do this conversion last night and I'm having a bit of trouble with spacing. Not sure if I've got the wrong callipers of the disk's are slightly different. My first attempt was with 240z hubs and 16mm spacer. This was pretty close but the disk bound on the calliper. Spacing the disk another 2mm just clears the calliper. One thing I have noticed is how tight the disk to calliper fit is. I have just over 1mm total clearance so the spacing has to be spot on or will rub 1 side or the other. I don't remember it being this close on the red car. I then tried the 260z hubs with a 9mm spacer it was nowhere near. I'll have another play tonight at get some proper measurements. Running out of time until the weekend so need to sort something.
 

toopy

Club Member
I tried to do this conversion last night and I'm having a bit of trouble with spacing. Not sure if I've got the wrong callipers of the disk's are slightly different. My first attempt was with 240z hubs and 16mm spacer. This was pretty close but the disk bound on the calliper. Spacing the disk another 2mm just clears the calliper. One thing I have noticed is how tight the disk to calliper fit is. I have just over 1mm total clearance so the spacing has to be spot on or will rub 1 side or the other. I don't remember it being this close on the red car. I then tried the 260z hubs with a 9mm spacer it was nowhere near. I'll have another play tonight at get some proper measurements. Running out of time until the weekend so need to sort something.

As you can see from this pic the clearance is tight!

What disc are you using? maybe it is a 1mm or 2 thicker!

HiluxCaliperZ31disc3.JPG
 

johnymd

Club Member
I cant really see the clearance from that picture. It's the back side where its machined to clearance the disk. I think the disks are 22mm.
 

toopy

Club Member
I cant really see the clearance from that picture. It's the back side where its machined to clearance the disk. I think the disks are 22mm.

Ah right, I havent got a pic of that side, but from memory, yes, it was tight. I remember looking at it as i was fitting the calipers and thinking will the pistons push in enough to fit the pads properly!
 
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