Purplemeanie

Thanks for the suggestion Geoff. I’ve got a busy holiday weekend to investigate all this. But great to have so many suggestions after I was thinking I’d got to the end of what could be wrong.

Thanks Ian. I'll check that out.

Thanks Jim. Some research needed into those points. John

Hi Jim, thanks for the questions, it falls short by about an inch or so. If I lift it back up with my toe then it stays up. It probably falls short 50% of the time (but dependant on how hard I prod - a vigorous prod tends to bring the pedal all the way up) and about one in ten now it falls short enough not to turn off the brake lights (which I've adjusted the brake light switch as far as I dare). Again, it doesn't fall short and is rock solid when the handbrake is partially applied. If I sit stationary in the car, apply handbrake and push the pedal - then the pedal remains high and solid even when the handbrake is disengaged. Only after some time and prodding does the pedal eventually drop. Did that answer your question?

Good point Steve. But yes, bled inner's and outer's multiple times. John

Elie boone, thanks, I have the notches set correctly yes. I wouldn't have been able to get the pads into the calipers if the notches weren't upright. I didn't test the MC disconnected from the pedal. That's a good suggestion though if my theory below doesn't work. The bleed tool is off amazon. I don't think it's that. It provides plenty of pressure to push fluid through the lines and out of the bleed nipples. I've been reading up on some people who think pressurizing is not as good as vacuum - and I've bought a vacumm system just in case to try if all else fails. The theory being that a vacuum causes air bubble to become larger and exit where they're stuck, not sure that it will make that much of a difference but clutching at straws now. I don't think its that now though. Current theory is that I didn't reset the LHS handbrake adjuster when I wound it in clockwise. I may try counter-clockwise and see if that works any better. Any advice on correct windback direction for RH and LH would be appreciated. Update: hmmm.... having done a more specific search on here it seems that Clockwise is the right way to windback both LH and RH rear calipers. Still looking for suggestions.

Thanks for the reply Chris. I'm thinking it may be that I didn't reset the handbrake adjuster correctly on the LHS. There isn't much slack in around the clevis. I wasn't keen to just wind up the nut on threaded rod into the master cylinder.. that seemed a bit crass. I think I'll have another go at resetting the handbrake auto adjusters when I get a chance. Update: hmmm.... having done a more specific search on here it seems that Clockwise is the right way to windback both LH and RH rear calipers. Still looking for suggestions.

SM25T, thanks for the reply... I already did the rear calipers. Handbrake slackened off completely. Wind pistons in. Pumped brake pedal - big and repeated pushes to reset. Only then re-adjusted handbrake. Do I wind pistons clockwise on both sides? I saw a post saying to do clockwise on both sides but rewind kit comes with left and right versions. Front calipers are fitted with bleed nipples at top - yes. I'm pretty sure the pedal does not return still if MC cap is off. What's happening there if it does? I will try that this evening though. Pedal return spring: Where is that fitted? Is it in the MC assembly or on the pedal assembly somewhere? The pedal returns fine to about 1 inch from the top of its travel - but I guess that's the pressure in the lines perhaps doing that. Update: thinking about this. Can't see that it's anything to do with the MC and/or pedal. If the handbrake is on (slightly) then the pedal returns perfectly and with good feel. It's got to be something to do with the rear or else the handbrake would make no difference.

Hi All, I hope I can impose on your collective wisdom again and sorry for the long post... I have a new build (by me) 420R with uprated 4 pot front brakes. The 420R also comes standard with the uprated master cylinder. I am through IVA and on the road but am finding the brake pedal feel is not as solid as I remember from test drives, and the pedal doesn't return to the top of it's travel. I have 160 miles on the clock... so open to the fact that this will get better... however... I'm concerned that with the pedal not returning to the top of it's travel, after pressing the brakes, the brake lights will stay on. I've adjusted the brake-light switch as much as I dare so that the brakes only stay on occasionally now, but I'm worried that the brake lights will stay on and people following me don't appreciate that I'm braking again. I've had a couple of near misses already - or is this normal for people to rear-end a Caterham! The brake pedal drops about half of its full travel with a solid push, and feels spongy (in non-assisted brake terms). The tech at Williams reported that I probably had air in the system and bleeding them should get the pedal firmer and it should then return to the top position after pressing the pedal. But... I've now bled the brakes 5 times. I've used the tried and tested: undo nipple, press pedal, close nipple, pedal up, repeat. I also bought a pressurized brake bleed system as used by the tech at Williams. Have used the pressurized system 4 times now. The next piece of the puzzle is that the brake pedal feel is rock solid if the handbrake is slightly on. So, having read various posts (though still not sure quite why) I have also slackened off the handbrake, taken the rear calipers off and wound back in the pistons. As part of this process I tipped and banged the calipers endlessly in the hope that any air pockets would be dislodged. I then fitted the calipers and pumped the brakes to set the pistons and reset the handbrake... no change. My current theory is that for some reason the rear brake pads are coming too far off the discs when there's no pressure on the brake pedal... partially applying the handbrake will push the pads closer to the discs and pre-engage them for when the pedal is pressed - hence a firm pedal in that situation. Any suggestions gratefully received. I have the club Novices Trackday booked for end of April and clearly keen to make sure I have great brakes by the time I get there. Thanks in advance, John

Thanks for all the feedback. Wishbones now installed. Will do final checks when the car is on its own wheels.

Hi Jonathan, As far as I can make out the upper Wishbones are identical OS vs NS. The ball joint orientation doesn’t seem to come into the equation. At the moment ScottR440D’s statement is my default position unless anyone can tell us differently. You asked where I am... Bristol. John

Thanks Scott... that’s sort of where I got to. The manual says they are handed but for all I can see you can interchange. Glad to hear Derek confirmed this with you.

Thanks Jonathan, that’s right the long leg faces forward... but... you can make the long leg forward with both of the Wishbones, you just have to flip them front to back. Still not sure which is the OS vs NS. john

Hi All, first post, so be gentle with me! :-) I’m just starting a 420R build and have got to my second day of build: front suspension. I foolishly took the wishbones out of their wrappers without paying attention to handedness. The lower wishbones are easy to identify... circlips face downwards. However, the manual says that the upper wishbones are handed but I can’t see any discerning way to tell the difference. Is there something to the geometry of the mounting points? I offered both uppers to the chassis on both sides but they both look feasible in both locations. ... any suggestions, what am I missing? thanks in advance, John