Quick :D are brake caliper bolts 3/8ths?
Turbo Mini Forums

Just a quick question, went to a nut and bolt supplier today to get new caliper bolts as the ones im using with my 4pots & vented disks were not long enough. He matched them as 3/8" UNF i think thats how you type it. I gave him the original bolt which only screwed in a few threads on the test 3/8"unf nut.

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

by the way just asking because im stuck at my mums house iwth the calipers off waiting to bolt htem back on, and didnt want to damage my hubs :)

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

Which hubs are you using? Mini hubs are 3/8 UNF, but Metro hubs are M10.

Also if you are using metro 4 pots on mini hubs you really need ERA turbo caliper bolts. The reason being that Metro calipers have a clearance hole for an M10 bolt. Putting a 3/8" bolt through to bolt a Metro caliper onto a Mini hub is a bit dangerous as the 3/8" bolt is slightly smaller than the M10 meaning the caliper is not located as well.

The ERA turbos used exactly that combination, Mini hubs with Metro 4 pot calipers, so Rover produced a special bolt that has a shank to suit the Metro caliper, and a thread to suit the Mini hub.

Edited by Tom Fenton on 15th Feb, 2005.

I have some here some era turbo caliper bolts, BUT to get the 4pots centralised over the disks i have to spacer them with washers, its been like this since i bought the car but with just 3/8bolts then. I will use the era bolts, but thats the problem im having that the bolt doesnt go far enough into the hub to keep me happy with piece of mind :)

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

so it is not possible to get some era bolts made up or do we need to order them from mini spares? i did buy a 4 pot kit and was told i had ERA bolts with them but they turned out to be normal 2 pot ones as i dint know what i was looking for. i guess a nut and bolt place would do them cheeper for a few sets than mini spares will do?

thanks, Dan

Why are you having to use washers to centralise the calipers on the discs? I have Metro 4 pots and Metro vented discs mounted on Mini hubs with no problems at all?

I think you will struggle to buy ERA type bolts from anywhere other than a Mini specialists or Rover. Nut and Bolt places are just retailers of manufactured goods they don't make stuff up generally. And the ERA bolts are such an oddball special that I think most places wouldn't want to do just a few, they would want to do a run of say 1,000 bolts......

Although thinking about it you could probably make some if you got some M10 bolts with a long enough shank to cut the threaded portion off, skim the shank to 3/8 UNF die size and then cut your own thread.....certainly possible but a lot less hassle to ring somewhere up and buy the correct thing......

mine are definately mini hubs, its just where the caliper sits, the hole that you look odwn to see pad wear isnt in the middle without the washers :/ i will be able to get a pic when i get home, do both pads have the same clearence on each side of the caliper on yours arround the disk? I use about 6-8 thin washers

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

What discs are you using? Are you using Metro or Mini drive flanges? Mine fit central to the disc e.g. equal space either side. To be honest they look like they could have been std equipment, e.g. fit properly with no bodgery needed.

ooh im confused now. I willbolts them together to get home to get camera and take a good photo tomorow. If it helps though i used a standard mini driveshaft & cv joint on one of them as a replacement last time. my wheels are an extra bit wider than using standard brakes though and my 13x7s are still wider than group5 euro arches.

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

As tom says, sounds like the drive flanges are the wrong type!

Oh ok! pot dan just mentioned that metro ones have a lip on them. Ill get a pic tomorow.

Next thing to think about though, if i go to the right flanges, i wont have bodged brakes but my wheels will scrub on the inner wings and i wont be able to get full lock. Ill have to decide whether i trust wheel spacers or bodged brakes the most :/

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

No the wheels will still be in the same place. What the right flanges will do is move the disc into the right place to line up with the caliper properly.

you sure tom?

Thinking (my memory is not too good) about the chamfer that the hub taper washer contacts, this is further inset on the metro vented, comapred to mini drive flange isn't it? So relative to the CV (a reference point) the outer face would be in a different place?
I could be wrong! LOL!!! Not even looked at a drive flange or touched a mini in months!!!

Edited by turbodave16v on 15th Feb, 2005.

I think you are right about the taper collar seat being more recessed into the drive flange, hence moving the face the wheel butts up to outboard (from the cv reference). But only moves it outboard a touch, from memory thinking about the difference in the flanges maybe 1/4"? But I also think that the flange itself is a bit thicker than the mini one, hence moving the face the disc bolts to inboard as well?

TBH that is the only variable I can think of that would cause the need for all the dodgy washers and longer bolts to make the calipers line up properly? I have only ever used vented discs or solid discs with their respective correct type flanges, but the calipers have always lined up correctly for me. As well if they didn't line up personally I would know something was wrong and wouldn't use them till I had found out why!
Just can't think of anything else that would cause the calipers not to line up?

i bought the original car with them like that i just accepted it :) tonite i have learnd its wrong and im glad to be honest that i know now. Going to ask dan if i can have the flanges off his black metro turbo when hes taking the engine out

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

BTW wasn't having a dig I can see it looks like I am.

But its worth making damm sure things like brakes etc are right, I am sure you know why!

With the metro flanges you need to cut off the 4 lugs that locate the metro wheels. Its not that hard a job you can make a good enough job of it with a hacksaw and a flat file, although if you can get access to a lathe or miller to finish them up then all the better.

oh yeah i know your not!!! your being really really helpfull on all my posts tonite i really am thankfull, you and turbodave always seem to bend over backwards to give me good advice, i can only get online a couple of nights a week. Usually it brakes down in the week, and ill ask the problems on the nights im online and fix it throguh the week :) I have a day off tomorow so im working on it all day :)

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3