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« on: 24 June 2018, 12:17:15 »
Around this time last year I replaced the front brake discs and pads on my 1996 V6. Not long after that I failed an MOT with a front brake imbalance being one of the reasons for the failure - I wasn't surprised as I could feel a slight pull to the right when braking. The MOT tester said it looked like left side was working slightly slower than the right, which would explain the pull to the right if that side was braking first, and said it might be a caliper or brake hose issue. I wasn't aware of any imbalance before changing the discs and pads but can't guarantee there wasn't an issue developing.
When I got home I checked everything, but couldn't find anything obviously wrong, so decided to work the caliper piston in and out a few times to see if that freed it if it was sticking a bit. I did that by putting in the worn pads back in so the piston would come out much further then pushing the piston back in with the bleed nipple open. At the same time I had a look under the boot over the piston and it was remarkably clean with no pitting or leaks from the seal. I also thought that rebleeding might help in case I'd missed an air bubble last time. I took the car back for a retest and it passed, but only just. I could still feel a slight pull but got the impression I might have achieved something with what I was doing.
I didn't do any more at the time as the imbalance only felt very slight and I hoped the system might bed in with use. Its now coming up to MOT time again and as I can still feel a slight use pull to the right I've had another look at the N/S front brake to see if any issue there has become more obvious. The disc still looks very good, the pads show even wear, the caliper piston still looks to be in very good clean condition and the sliders are still move freely.
As the imbalance showed up on the testers rolling road last year I'm discounting any suspension or tracking issue that might cause pulling to one side under breaking and I'm not convinced the brake hose is at fault as I would expect flow issues inside the hose to cause binding or slow brake release which is not happening. Everything keeps leading me back to the caliper being at fault and I'm wondering whether there is greater resistance on this side even though it appears to move out and push back in ok.
Many thanks if you've read through all this, I'd be grateful to hear whether others would agree that its most probably the caliper or whether there is something I've completely overlooked. I've thought about trying another caliper from a scrapper but its hard to guarantee it won't have been on the shelf for years and possibly seized and corroded.
Finally, does anyone know where I can get some bleed screws for the Lucas caliper - I'm not sure if they're a standard metric screw or if they are specific to that unit. Thank you.
