Fortunately there was enough adjustment - I needed to adjust it about 10mm which is a lot when you consider it attaches only part way up the pedal arm... I think this must be due to a difference in length of the replacement rear cables rather than stretching as I can't see it stretching permanently that much.RichardW wrote: 13 Sep 2024, 16:27 Good to hear you are making progress Simon! I would set up the shoes first to be just clear (or just brushing), and then set the cable so the brake comes on at the right no of clicks. Hopefully there is enough adjustment to take up the slack, I doubt you will have stretched it much, they are pretty robust!
In any case I seem to be 95% of the way there but still have a minor issue.
In summary I found the following issues:
1) The original Triscan shoes were for the earlier Leaf with the electronic parking brake and did not fit at all. Cleeverly acknowledged a mistake in their listings and replaced those with Delphi shoes for the later (correct) Leaf and those fitted, however I still had an issue with binding when the disc was pushed on the last bit and bolted up.
2) There is clearly something wrong with the Triscan discs as well even though they are the correct part for this model of Leaf. If I had to guess I would say the drum section has not been properly machined and may not be perfectly centralised on the axis of the disc, so perhaps held incorrectly when machined, also the inner drum surface finish is very rough compared to the Bosch disc which is smooth and looks like it just came off a lathe.
The quality of machining of the Bosch disc is clearly superior to the Triscan when comparing them side by side and there are some significant dimensional difference in some places that are visible to the eye. The Bosch discs slide on and off with the adjuster in the adjusted (not slackened) position without any grabbing or binding when the disc is bolted down. Not sure exactly what the issue is without precision measuring tools but the previous discs are definitely not satisfactory.
Another change I've noticed is that I had noticeable vibration above 75 indicated with the original rusty discs and shoes and suspected the brakes were the source of the vibration and fully expected it to go away when I fit the (first) new discs, shoes, pads etc however it did not go away!
After fitting the Bosch discs today and giving it a motorway run during part of the testing the vibration is completely gone even well above the speed limit.... 
This just makes me even more sure there is a problem with the machining of the Triscan discs and that the inner hub may be machined slightly eccentric - enough to cause both grabbing and vibration.3) The cable adjustment on the pedal was so far out that even with the pedal on the floor the pedal wasn't really offering any resistance and the brake could barely slow the car. Now that I've thought about it some more I suspect the difference is a small difference in length of the after market rear cables rather than stretching of the front cable, and I was not aware there was an adjustment or where it was and how to get at it until I noticed it in the service manual. I've watched several Leaf handbrake servicing videos on Youtube and none of them cover this adjustment or even acknowledge it exists and needs checking!
It's clear now that with this not adjusted properly there is a lot of lost motion in the pedal and it's impossible to adjust the rear adjusters to let the brake apply properly but still be able to release fully as well. The front adjuster needs to be adjusted to the point where there is still a little bit of tension on the cable when the pedal is released however it was nowhere near this. The Nissan data says 200N of force for 7 clicks but I've had to judge it by feel.
Once that is correct there is now the maximum amount of motion of the cable at the hub end and the adjusters in the hub can be adjusted to give sufficient bite but still be able to release properly. I've given them some bedding in, and they now work well forwards to the point that the handbrake will stop the car from 30mph in about 10 seconds - not amazing and certainly not as good as the handbrake on the Xantia was, (which was amazing) but about what you'd expect from a rear drum handbrake.
HOWEVER and here is the but, the handbrake still does not work properly in reverse, and this was an issue with the original discs and shoes for at least a year before the handbrake stopped working. It would lock solidly forwards but let the car roll backwards unrestrained. (Aside from the parking pawl in the gearbox)
The original shoes were very unevenly worn - with the rear shoe being much thinner than the front one and I assumed this was the cause of the discrepancy, since the forward shoe is the leading shoe for forward rotation and the rear shoe is the leading shoe for reverse rotation and it is the leading shoe that achieves the lock up.
However I now have new discs, new shoes that are thick and even and it STILL locks well forwards and slips in reverse. In fact just the automatic creep from putting car in reverse is enough to overcome the handbrake in reverse despite it being able to stop the car from 30mph forwards.
Now I suppose I could attempt to tighten the adjusters a bit more (I was going to wait until the shoes are fully bed in) but I really don't understand why it could lock up solidly forwards but slip so badly in reverse. Can anyone help me understand this ?
Do I just need to let the linings and drum bed in a bit more then recheck the adjustment or is something else going on here ? It will pass the MOT I'm sure as they only test the handbrake going forwards, (if they didn't it would have failed the MOT years ago) but I would obviously like to get to the bottom of this...
I still don't like this design of handbrake and feel that the handbrake in the Xantia was vastly superior, simpler, more reliable and much more powerful...
