Well I have finally had the brakes on my Motortrike adventure (2007 1800) de-linked.
In the end I had my trike builder do the work in exchange for the saddle bags I took off the original bike. When the Bike was originally converted to a trike I also worked on the conversion.
Are they any better, Well when I first got it back from the workshop ( I hadn't worked on this change over) The braking had improved but still not what I wanted. There was also too much travel in the brake peddle for my liking. I re bled the rear brakes and although there was no sign of any air coming out of the system the peddle movement had become more to my liking. There had been a new mechanic in the workshop and I fear that he may have done the finishing work on the brakes. It is very important to get the correct bleed nipples and the correct order. Only the top two nipples should be bleed. and start with the furthest away from the master cylinder.
My final act when I had finished all this work was to use an old racing trick to finally clear all the remaining air from the system , Fine air bubbles can collect in the top of cylinders etc. These are incredibly small fine air bubbles which cannot usually be seen by naked eye.
I fasten down the foot brake peddle (you can also do this with the front brake as well) until the peddle is completely solid. Remove the brake fluid reservoir cap and leave it like that for at least over night. Those little devils will be forced back down the line and out through the reservoir. This really does work!
The braking had improved some but still not what I wanted as I do pull a trailer on our holiday.
I had research the actual axle that Motortrike have used for the adventure Irs.
This is from a 2002-2005 ford Explorer. The brake pads also come from this same axle.
My next move was to find a better (more cold friction brake pad) EBC make one intended for competition use. Greeenstuff (DP61631). These pads are identical to those used by motor trike. BUT! they are about 0.5 mm too thick.
I took the chance and ordered a set for the UK stockest. I then carefully reduced the thickness by scrubbing then on emery cloth on a completely flat surface . checking all the time to make sure that they where level and square. It worked.
I now have a trike with astonishing brakes, something that I have confidence in if I was pulling a trailer .
Thanks to all those who had previously joined in this thread and had given advice.