I’m going through the final stages of converting my RHD 1990 V12 XJS Auto to a manual box. I had to replace the existing ABS pump & accumulator (the old one decided to pack up during the conversion), the ABS warning light then went out and all brakes have been successfully bled.
However in order to turn any of the wheels (the car is on axle stands) the brake pedal has to be pulled up slightly towards the driver, meaning that in its resting position, it is applying pressure to the system and the pads are gripping the discs.
Has anyone come across this before? Could this mean a failing master cylinder? The company who supplied the conversion kit haven’t seen this issue before.
BwBe glad you have brakes. My 92 model has the pedal on the floor, a Teves 3 system and I have gotten a world of advice on here to try to correct the problem(s). I now own two accumulators and have sourced O rings to reinstall one of them. A major brakeline bleeding is now in order. Failing that, we retrofit the early system of vacuum booster and conventional master cylinder.
Since you had to modify or replace your pedal box to add the clutch pedal, you need to check that the pedal return spring(s) is in place and properly installed such that it raises the brake pedal when your foot is off the brakes. I don’t know if it is possible to install it backwards such that it constantly put pressure on the brakes, but check for that also.
Since the beginning, cars have had brakes, and some were cables that manually actuated what they called brakes. Then, hydraulics were used, and they worked for the better part of a hundred years. Now we have computerized brake systems with fail safe mechanisms to save us from ourselves. In all the years of owning cars, the brake problems consisted of worn out shoes and drums and rotors, but no issues to speak of.
I need to understand the current thinking, and try to justify the complexity involved.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
5
Note, however, that the backup for the hydraulics is still a cable-operated brake. I suppose someone thinks you can get at that thing in a panic when your hydraulics fail.
Apparently there are different versions of the actuator rods. The company that provided you with the kit for you may have shipped a rod that is tiny bit longer.
This is a good idea. Those big “mousetrap” springs are a bit challenging to re-install, it takes 3 hands, a cooperative wife and the proper language. Set up properly they hold the pedal all the way “up”. Since you can apparently raise your pedal “up” by pulling on it, it sounds like the spring is missing or somehow wrong.
So it turned out it was indeed the pedal spring(s). Instead of having 2 springs to help push the pedal up, there was only 1, and it was pushing it down. Pic shows the original one from the autobox on the right, and pedal supplied for manual conversion on the left. Bit of a pain to refit and bleed the brakes and clutch but certainly easier than holding the brake pedal up the entire time your driving!
