I finally got a day off work today  Thought I'd make a start on swapping the LWB brakes onto my Vit.

Pic showing how much thicker ventilated disc is. I contemplated spending some time cleaning up the disc but then decided against it as it will only go rusy again first time it rains:



This was a surprise, the top disc is the original 8V SWB with Lucas/Girling caliper, the lower is the LWB disc, notice that the SWB disc has a much greater swept area. The other side of the LWb disc was similar to the SWB, both discs were the same




Ventilated disc in place. I had to spend some time cleaning up the rear mating face with a wire brush to get the disc to sit square. When I first checked the runout I thought it was warped! The disc shield/guard rubbed a little as Wild said it would. I considered modifying it but I have had problems with trapped stones (what a noise!) in the past so I just cut it off.



LWB piston next to SWB caliper, not easy to see the difference like this



Vernier calipers show a difference of around 4mm, LWB is 53.5mm against 48.1mm for the SWB.

Caliper bolts straight onto SWB hub, the paint I used wasn't completely hard and some of it got smeared when I fitted the caliper. I'm not too fussed, the main reason for painting the caliper was to keep everything clean when I reassembled it. The paint is some high temperature radiator paint from the local DIY superstore, choice of colours was very limited, I couldn't fine any 'proper' brake caliper paint locally.

looking good.
does this mean we are going to see the vit back out and about then.

Not for a while still lots to sort. At least I have somewhere to sort stuff now I have been doing the brakes in between rain showers. While it was raining I hooked up the lights in the garage and installed the first power point too. Now I have a watertight roof, a bench, lights and power - luxury, pity the Vit won't fit in it, lol.

didn't make the shed big enough then, did we. 
At least you have a garage.

I replaced the other side today. Now I have to make sure that the m/c can push enough fluid to operate the bigger calipers and the rear disc conversion. There isn't enough room for a bigger booster



So its time to hunt for a bigger master cylinder. I pulled the stock one to strip it and measure it up. There is a plastic cover over the end of the piston. Its not shown in the FSM and doesn't look like it will come off without damaging it in some way. The end of the piston is 5/8", the outer diameter of the m/c is 1" so the piston is more than likely 7/8.



I won't be able to visit any breakers until next w/e. Heather (IIRC) posted the size of a Subaru m/c as 1 1/16" so I am optimistic that I will find something to suit, I might have to hunt around a bit though.

My stock mc works fine with the bigger brakes on the toyota axles.
you sure you need to change it?

I don't know about the Toy axles on the LWB, I would imagine that the bigger brakes would need less pressure to achieve the same braking effect so up to a point maybe it cancels out. With the rear discs there is far too much pedal travel, the rear calipers are free and the handbrake adjusts up properly so I know they're not faulty. Nick fitted a Residual Pressure Valve to his to reduce the problem. The Residual Pressure Valve was designed as an anti-syphon valve for cars with the m/c below the level of the rear brakes, I'm sure it works but the problem is not enough fluid and I would rather fix it by sorting that out. I still wonder if the LWB is different in some way, its possible that it could have the same bore m/c but a different pedal box/mounting arrangement that would give it a longer stroke. To achieve that on a SWB would mean moving the pivot point, which is possible but would put the linkage at a poor operating angle (IMO). Even that may not be possible as I haven't looked at how much of the possible stroke is actually used.

1 1/16" will push a 47% greater volume, 1" will push 31% more. I will have to see what I can find.

I have been looking at a few threads on other boards it definately seems like the Subaru m/c is the way to go with rear discs. I have also discovered that there is a Subaru breaker in High Wycombe too . Fingers crossed that the Lucas m/c is a straight copy of the Aisin version.

fingers crossed, fingers crossed. 

I have been runnning the bigger brakes on my swb for a year plus now and the improvement in braking was noticable.  they made a big difference even on the stock M/C.

its been MOTTED as well with no issues on the brakes.

I think sometimes you knwo to much which gets you thinking

I have been runnning the bigger brakes on my swb for a year plus now and the improvement in braking was noticable.  they made a big difference even on the stock M/C.

its been MOTTED as well with no issues on the brakes.

I think sometimes you knwo to much which gets you thinking

Yes but you don't have the discs on the rear. Its that that is the real problem not the fronts, I haven't at any point said that you have to have a bigger m/c because of the LWB fronts. Mine was MOTd as well but the brakes were still rubbish.

Theres more info on the swap here:

http://bbs.off-road.com/ubbthreads/showflat.php/Cat/0/Number/1205468/page/0/fpart/1/vc/1

I'm pretty busy with diy stuff this weekend although I did manage to get to a local breakers today. I had to go to the local tip and there is one right next to it  . I found out that my master cylinder is exactly the same fitting as some Rovers, which is good because parts for them are cheap. The couple I saw were two port and the Vit is three port. I will phone a Rover specialist in the week and try and find out if they ever made a three port.
While I was there I grabbed a 2 port m/c from a Rover 416, it looks slightly bigger in diameter (maybe 15/16") but most importantly it is disc/disc. If there aren't any 3 ports then I will use that with a splitter.

good to see you back and fiddling around again - we must get that Wiltshire trip done when the Vit's back off the road

Yeah, that would be good. I liked laning in Wiltshire, have to see what the government have left us now though.
I'm going to try and get round to stripping both m/cs in the week just to see how different the rear brake piston set up is and also so I can get an exact measurement of the pistons. I'm guessing the Rover one is slightly bigger because the body is a couple of mm bigger.

I'm gonna fit Swift rear disc callipers because they have a handbrake fitted in them. I've looked at the swift MC and the dia is a little smaller, but the swift front callipers have a bigger cilinder. So I'm gonna try to fit the swift rear callipers and MC. If I'm thinking about this right, the swift MC should push enough fluid to the front callipers (as they're smaller) and also to the rear, because they are what originally is fitted to the MC. Am I overlooking something here? Or might this be something to try for you too James?