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Brake pad knockback

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Old Nov 6, 2018 | 05:54 AM
  #41  
mx5-kiwi's Avatar
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Sweet thank you.

We were sure it was failing or bad bearings but that just doesn't seem to be the case. We fekt the same about air/beeding, but that also doesn't seem to be the case.

So strange the problem only happened after we changed our system (Superlight brake kit and removed Booster, retaining OEM M/C, mechainc did a nifty trick to retain OEM pedal feel)...im thinking for our next race meeting to go back to the Dynalight to try and rule in or out parts.

and this low speed version of it has us beat too. I just can't see that being a flex issue unless the thing is nearly torn in half.

Superlight Kit has only done 1.5 race meetings, so pads are barely touched at this point (plus it did it from new so doubt pad wear is the issue ).

We have oem hubs still. What do you look for with failing wheel hubs?
Old Nov 19, 2018 | 03:58 PM
  #42  
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I have seen weird caliper piston pushback with certain pads (not sure why..) but the pad cycles between convex/concave bending due to thermal expansion. Using IR temp sensors you can verify that the pad contact surface has fairly uniform and consistent heat traces, not hot edges alternating to hot centers.
Old Nov 19, 2018 | 04:24 PM
  #43  
mx5-kiwi's Avatar
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While I dont think our underlying issue is resolved.

Further to suggestions above, we did fit the willwood 4psi residual pressure valves and that has made the issue a one press of the pedal solution. So it is now very driveable.

Given our problem was extreme I would think for anyone with a mild case these would bea great solution.

No idea what our issue is given it happens just in the car park IF you turn a corner but for the moment we will see if anything becomes apparent.
Old Nov 19, 2018 | 05:36 PM
  #44  
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No. Stop it. You are adding unnecessary parts to bandaid a major hydraulic bleed issue. Residual valves are for drum brakes, and they have no place in a proper disc brake system.
Old Nov 19, 2018 | 05:42 PM
  #45  
mx5-kiwi's Avatar
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Thank you for advise (seriously) and that is my concern, but we cant reslove how/why it stays pumped up without going round a corner..... "sometimes" even after a corner it stays up, but mostly turn the wheel and go round a corner even at carpark speeds, it will drop to half of what it is.

We have power bled many times, with no air.

Has it ever been necessary or known for Superlights to be bled any different to the other dynalights/dynapros ?.....i.e. from the underneath bleed nipples as well?

edit: doesn't seem heat affected either. I would have thought a bleed issue would be heat affected......?
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