R32 brake fun...

[predator]

This afternoon I had a bit of a play with the brakes, to see how difficult it is going to be to change my single-pot "non-mspec" to "m-spec" 4 piston jobs, and also at the same time change over for the slotted rotors I have picked up.

Few things I discovered..

* "M spec" discs are much thicker than the non-mspec.. they won't fit at all with the single-pot calipers due to the width. Basically m-spec and non-mspec I believe are totally different discs... Unless the DBA ones I have are especially wide(??)

* The non-mspec and m-spec are same diameter discs.

* "M spec" and "non-M spec" pads are totally different. The single pots don't look too much different to the brakes on my R31.. maybe even the same.

* It appears as if the brackets for the "M-spec" are different to the non-mspec and means the calipers won't swap over due to the different bolt positioning.. interestingly actually the non-mspec is wider apart.. Looks like I am going to have to track down these brackets - and if they don't fit into the standard hub position don't know what I am going to do :-s

* The 4 pot R32 brakes are a curious one.. with pins and clip arrangement actually slipping through the pre-defined holes in the pads to hold them in place (to prevent slippage?). Very strange, never seen this before.. and in my old R33 I believe there wasn't this arragement at all.. the pads just sat in the caliper held firm in place, like any other car I have seen.

* Looks like the brake line bolt on the 4 calipers is the same as the single pot caliper. So the brake line at least shouldn't post a problem.

[predator]

p.s. looking at the conditon of the old you can probably see why I want to change them over..

Also.. my question from this thread is .. how do I remember the actual front hubs?

The rears generally you just slip off over the studs.. but the front ones is firmly be held in place.

In the last photo you can see the huge bolt (22mm?) off the back, which is covered by a dust bracket. Is this what I have to unbolt to get the old hub off? There is stuff all room to manuver there. So do I have to brace the front of the wheel, whilst using a socket wrench on it?

Or do you just bash the hub forward with a rubber mallet?? Unfortunately the damn bracket bolts are going to require a breaker bar or something :-s as they are budged tight. Nearly snapped my 3/8 socket wrench trying to get them off!

[SteveL]

* It appears as if the brackets for the "M-spec" are different to the non-mspec and means the calipers won't swap over due to the different bolt positioning.. interestingly actually the non-mspec is wider apart.. Looks like I am going to have to track down these brackets - and if they don't fit into the standard hub position don't know what I am going to do :-s

Perhaps I misunderstand you, but try undoing the 2 large bolts you can see in the extreme RH photo of your pics. The old caliper bracket should come away and then with any luck the 4-pot caliper will bolt straight up using those bolts. You might have to trim the backing plate to clear.

[predator]

You could well be right as the bolt holes on the m-spec align exactly with those yellow marked bolts. Unfortunately as I couldn't actually get the bracket off, couldn't tell whether it would fit.

Thought if it did go in there.. may be a bit far back to actually sit on the disc?

Does anybody have any "mpsec" brake pictures for R32.. preferably from behind? Not sure whether the service manuals I have cover brakes

[SteveL]

You could well be right as the bolt holes on the m-spec align exactly with those yellow marked bolts. Unfortunately as I couldn't actually get the bracket off, couldn't tell whether it would fit.  

Thought if it did go in there.. may be a bit far back to actually sit on the disc?  

I think you'll find I'm right and once you get the old bracket off the new cals will bolt up np.

By 'front hubs' do you mean the discs themselves ??....or do you have a problem with the wheel bearings and the hubs need to come off ??

Anyway, to get the discs off you need to get that bracket off first, but the bolts can be a bugger if they haven't been undone in awhile (corrosion, etc). Once the bracket is off, the discs should also slip straight off. If they don't (again, corrosion,etc) you will see that the discs have a couple of drilled and tapped holes with no bolts. Just screw a spare bolt into each of these (either 6mm or 8mm, I can't remember) and tighten them up and the disc should pop off.

BTW, don't undo that large nut, it holds the stub axle in place.

[predator]

Had another go today... Old disc just needed a bash with the hammer from behind to get it off. That is all I needed to get off.

Exaclty as you said SteveL.. you just remove the whole bracket for the single pot, and the 4 pot just bolts up exactly to that position. Have to bash the dust shield out the way, but that is nice and thin so not a drama

All was going great UNTIL the final step when all went pear The calipers and discs were bolted in.. Unbolted the brake line from the back of the single pot.. brake fluid starts coming out which I knew would happen.. so I quickly do that and start bolting it into the new 4 pot caliper as quickly as possible as to not lose too much fluid.

Hang on a sec.. its not sealing properly and fluid is still coming out, even though it feels like its fully bolted in.. keep bolting giving it some strength.. **** !! stripped thread Basically I've stripped the thread for the brake line *on the caliper* which is a bit of a disaster... the "eye bolt" or whatever is that secures the line to the caliper is that extra 10mm longer than the single-pot calipers, not allowing a full seal. Of course me being a dickhead just kept tighening it, not realising this until it had stripped the thread. Thought everything else was so similar that the bolt would be the same but obviously not.

I don't really know what to do now.. either that caliper is stuffed completely.. or I try and get a slightly larger eye bolt, somehow rethread the hole, and pray it can all work. Does anybody have any suggestions??

I'll have to go down to pirtek or somewhere like that and see whether they can find me the right sized eye bolt so it doesn't happen on the other side. Its the same diameter, just different length.

But i've still got one farked caliper that is going to need some clever ingenuity or its $150 or something down the drain ..agg!!

[SteveL]

I don't really know what to do now.. either that caliper is stuffed completely.. or I try and get a slightly larger eye bolt, somehow rethread the hole, and pray it can all work. Does anybody have any suggestions??

Sorry, I should have picked this up from your photos....the 4 spots don't use a bolt (banjo bolt in old terminology) but use a flare nut and a short length of pipe to connect to the flexible hose. You could possibly get away with shortening your existing bolts, but the surface of the caliper isn't machined to 'conform' with the sealing copper washers used for your old cals. Worth a try, but the other option is to get the m-spec brake hoses and fittings.

In terms of the stripped threads, it should be possible to use a thread repair kit to fix it (re-coil or heli-coil) and a brake specialist should be able to help. Thread is M10x1 from memory and shouldn't cost much, but whoever does it should make sure they don't allow swarf into the cal (strip it down for cleaning before or after would be best)

[Duncan]

oh noes not stripped at the caliper Damn. good luck getting it sorted and let us know how you fix it

[predator]

I think rethreading it will be the go like SteveL says.. which I know nothing about. First of all it looks like I need to get the proper lines (error #1), as they're obviously different now somebody sent me some pix. So I am on the lookout for those.

I'll probably take it to a brake specialist to get them to rethread the caliper, but its not going to be until january now grunt..

[Chris32]

Hi Gordon,

Sorry to hear you have had a few drama's Should be able to get the caliper fixed and re-threaded, I'm sure your not the first person to do it.

Hows this, when I put my 33 brakes on, I couldn't bleed them properly, and after going through a litre of motul brake fluid, it still didn't feel 'right'. Went to a workshop, 'casue I thought I bleeding it in-correctly - turn out I put the calipers on the WRONG SIDE!! and the bleed nipple was at the bottom, air was being trapped up top and not being able to be bled out!!

I'm sure it will work out ok and be fixed no probs,

Chris

[Targa Tom]

Hi Gordon,

Sorry to hear you have had a few drama's Should be able to get the caliper fixed and re-threaded, I'm sure your not the first person to do it.

Hows this, when I put my 33 brakes on, I couldn't bleed them properly, and after going through a litre of motul brake fluid, it still didn't feel 'right'. Went to a workshop, 'casue I thought I bleeding it in-correctly - turn out I put the calipers on the WRONG SIDE!! and the bleed nipple was at the bottom, air was being trapped up top and not being able to be bled out!!

I'm sure it will work out ok and be fixed no probs,  

Chris

LOL. and you had the courage to let other people know.... I'm still grinning.

Merry Xmas brake guy

TT

[Roy]

LOL...thats the whole point of the forum isnt it...you can learn plenty from reading about the mistakes others have made:) Things is many ppl are too prould to admit it, more credit to those that post/share the downsides of mods/ownership...me i wear my ineptitude like a girl guides...i mean scout badge:)

Predator, did you get the calipers rebuilt first?

I ask as i need to get new piston boot for my front right caliper. I had the bastard rebuilt about 18-24 months ago, but i suppose the high temps of the track knock these seals around a bit:(

Thought id give them a go myself this time, just need to get a price:) (To compare to Race Brakes)

[DLuded]

does anyone have any idea if r33 front brakes will fit on a gtst (non m-spec).

also how can i tell my call is a non m-spec. i dont think mine has the 4 spot calipers, can someone show me a pic of 4 spot calipers....mine doesnt say "nissan" on the cailipers

thx for the help

[predator]

r33 brakes will fit fine as long as you get the r33 discs..

dluded: sounds like u don't have mspec.. the single pots don't have a nissan on it like the others.. best way to see is just to pull the wheel off and have a look. first photo shows the rear of the single pot, as you can see its just one big cylinder there. It also has the bracket (2nd photo), and you will be able to see the actual brake pad if you directly face the disc.

Mspec will always have the nissan on them (far as i know). You can see in the 3rd photo i posted, the mspec caliper (painted in this case) just in the very corner of the shot.. its much larger, and has 2 pistons front, two pistons back.

brake fun resumes when i get back home ...

[predator]

well *finally* finished most of this off yesterday for both sides.. turned out that caliper, whilst the thread is slightly stripped, still takes the proper flare-nut off the proper Type-M lines ok, because i think it has thick thread. So didn't need to get that rethreaded - if it starts to leak I'll have to think about it I guess.

I did manage to snap the metal line (nut was seized shut, causing the line to twist) that goes to the master cylinder, so going to have to get that repaired before the job is completely done Nothing ever goes perfect when things are old and gummed up. Otherwise everything is in place, ready for it to be bled.

Basically once you have the proper "type m" brake lines, it's a fairly easy process. And that would go for R33, or maybe even GTR brakes.

I have nearly finished writing up a tutorial on how to do it, with photos and everything. If anybody needs a hand with the process, let me know and I'll try and help out..