Lotus Elan

Excess travel/spongy brake pedal after front caliper swap

PostPost by: MrBonus » Thu Jul 16, 2020 5:35 pm

So my original front calipers were in need of a rebuild and finally one locked up on me while driving, fortunately a hundred or so yards from my driveway. I decided to replace them with brand new units from RDent rather than rebuild.

The brake lines were replaced last fall and the master cylinder was rebuilt about 25 miles ago this spring. Prior to the caliper locking up, the pedal was super firm and the travel felt proper.

We bled the brakes twice after the caliper swap and now, there is probably 3-4 inches of pedal movement before there is any sort of braking force then a spongy inch or two after that. The system is definitely not leaking anywhere and it locks the brakes up no problem, but it feels wrong.

I've read a bunch of threads on this issue.

-Could it be the travel of the piston in the caliper? I read to check the pad distance from the rotor but I'm uncertain how to fix this on a brand new caliper.

-Could it be that it wasn't bled hard enough? I read a few posts about leaving a stick lodged on the pedal overnight to work any air bubbles out.

Sorry if I'm asking what appears to be a common problem but it just seems like the solution is something simple and I'm missing it.
1967 Lotus Elan Coupe - Super Safety
1971 VW Karmann Ghia
2019 Tesla Model 3 Performance
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PostPost by: MrBonus » Thu Jul 16, 2020 8:14 pm

Please disregard. A third bleed fixed everything. All is well.
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PostPost by: gjz30075 » Thu Jul 16, 2020 8:49 pm

Did you do anything different on this third bleed job?
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PostPost by: MrBonus » Thu Jul 16, 2020 10:44 pm

gjz30075 wrote:Did you do anything different on this third bleed job?


Yes! Mounted a pedal stop (ie wood) to prevent the spring from fully retracting on the brake pedal.
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PostPost by: denicholls2 » Fri Jul 17, 2020 5:31 pm

I know it's not the problem here, but just sticking this on the thread. Many people think the bleeders are drains and put the calipers on the wrong side when replacing them, with the bleeders pointing down. This will result in the caliper being filled with a lot of air and a spongy or, more likely, useless pedal. Air drains up, fluid drains down. :)
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PostPost by: h20hamelan » Sat Jul 18, 2020 1:16 am

sometimes, one must close bleeders. stomp on the brake pedal, which pushes any excess air through.
also, perform a forward and reverse fast breaking on tarmac. and on gravel (without abs)
not sure if its snake oil. ive read "lightly tapping the calliper with the nipple wrench"
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