I do hope someone has solved this situation, which may be common amongst some CFMoto models. When I first bought the Quadzilla ES500 some years ago I thought the brakes were quite good as I was comparing them with an ancient Yamaha. However, I have since discovered that the rear brakes are not working at all and I suspect that they have not worked for some years.
The owner manual and the workshop manual both state that the front right brake lever operates the front brakes whilst the rear brake is operated by the left hand lever and foot pedal. The pedal has always gone to the floor. The mechanic found out that the rear pedal drives a master cylinder which, if you follow the routes of the brake pipes, operate both front and rear brakes. Local dealer says that it was changed to ensure it is road legal in the UK. However, I have now had the rear brake master cylinder replaced and the mechanic has followed the instructions on bleeding the system as stated in the Dealer Bulletin but there is still no effect on the brakes - front and back. This will need much more research. (After he replaced the front pads the front brake was not too good too. However, this was sorted by tying the levers to the handle and leaving overnight! I know a few things about physics and was surprised when this brought the front brakes back to normal!)
The mechanic has tried many combinations regarding bleeding the brakes but to no avail. He suggests trying the trick with tying the levers to the handlebars overnight tonight but he has no idea if that would work.
I suspect that this could be complicated due to the modification for the UK market whereby the brake pipe from the rear master cylinder goes into some sort of box whose outputs are the feeds for front and rear brakes.
Any help would be gratefully received as I have already spent a few "quid" on the mechanic's time as well as for a new master cylinder which it probably did not need.
(Wife has just bought a 300cc Kymco quad and the brakes are lightning sharp on that one.)