Brake Pedal Travel?

[Geoff Brown]

#24 ChrisC - 'jiggle the handbrake' is fine as long as new rear pads have not been fitted.

With new pads fitted & the pistons wound back it is imperative NOT to operate the handbrake until the system has been initially bled.  After which with the pads should be settled in by use of the foot pedal.

In my experience bleed the system again THEN operate the handbrake. Bleed again & again............

If the handbrake is operated before the pads have been settled in the consequences are that more than likely the pistons will have to be wound back again to 'reset' as the caliper will be, as it were out, of synch.

The other thing some times overlooked with Seven brake bleeding is that front 'big' brake calipers have two bleed nipples. Bleed inner first then outer otherwise pesky little residual air bubbles will be locked in.

[Nigel B]

#24  At about this time last year I spent the best part of a week repeatedly bleeding the brakes & I posted on Blatchat at the time, asking for any tips, hints or experiences. I think you suggested those methods at the time, Chris & I did an awful lot of handbrake jiggling & caliper tapping, but sadly it didn't improve matters, in my case.

#25   7 Wonders, I did try bleeding the brakes with the rear calipers angled upwards & also removed from the car. I replaced the dedion brake lines with braided hoses, as holding the calipers as high as possible while bleeding was another method suggested. I also tried bleeding the brakes with the pistons wound fully in (handbrake adjuster nut slackened fully off), but that didn't improve matters either. I'm also aware that the 'pips' in the pads need properly aligning with the recesses in the pistons & that the brake pedal needs a firm press to let the pads self adjust, before adjusting the hand brake. I definitely didn't do any fluid bottle shaking!

 I also tried gravity bleeding & I tried reverse bleeding the system by pushing fluid up from the calipers, but again, to no avail.

I can't help feeling that for some reason, Caterham's current braking set up simply does result in an unusually long, squishy feeling pedal. My last Caterham had a much shorter, firmer pedal & I didn't have any problems with bleeding the brakes on that car. I've spoken to a fair few owners of recent cars who have told me 'mine's the same!'.
 

Last spring, I asked Luke Stevens for his opinion, when he was fitting a set of throttle bodies to my car & a few weeks later I asked DPR for their opinion when they were setting up my suspension & both were of the opinion that my brakes felt good. 
 

I was reluctant to fit a high effort pedal, as I felt it was a 'sticking plaster' type solution that would simply mask the real issue that was air in the system. But I'm very pleased I fitted one in the end, as I now have a short travel pedal, with good feel. I can heel & toe automatically, without really thinking about it, as I did in my old car. I'd go as far as to say, I think it's the best modification I've made to the car, I appreciate it every time I press the pedal!

[7 wonders of the world]

Do you run any anti squeal shims, metal or wolverine type on your pad back plates - these can contribute to a little spring in the pedal - and a cheap cheap fix too.

[Nigel B]

No, there are no anti squeal shims front or rear. 

[BrettJ]

So I bled the brakes again on the weekend and the pedal feels slightly better. I jacked the back of the car up to get the nipples as high as possible and even tapped the calipers with a rubber hammer while bleeding them,  I did get a few bubbles out but not more than two or three out of each caliper. One thing I did notice is that when I first time press the pedal it travels about 2 inches and is rock hard, but if I release and press immediately it only travels about an inch the second time. If I leave the brakes for a minutes or two and press it again it will travel 2 inches again. Now I know that I did operate the handbrake prior to bleeding the system during the build, would this cause this type of behavior and what is the best way to reset the handbrake mechanism in the calipers?

[7 wonders of the world]

Brett

your missing the point - the Sierra caliper were design to be fitted vertically si you need to remove he mounting bolt to enable you to rotate the caliper through both axis ti get the nipple vertical and allow the air pocket trapped by mounting the calipers horizontal out.

Your description shows the pedal is pumping up therefore you still have air in the system.

 

[SM25T]

You need to slacken handbrake lever adjuster, then wind pistons back into calipers cliclockwise. Refit pads then press brake pedal hard a few times.  Then adjust handbrake .

[BrettJ]

So I bleed the brakes again today and the pedal feels good, when I drove the car I didn't even notice how many travel there was on the pedal as it just felt normal. The process I followed was to slacken off the handbrake adjuster, then remove the rear calipers one at a time and wind the pistons back. While the calipers were off and the wind back tool was still in place as able to get them to almost a 45 degree angle. I then bleed each caliper, to my surprise there was quite a lot of air which came out.

[7 wonders of the world]