Sorry this is a long one...
The brakes on my 405 have always been a bit spongy and slowly got a bit worse over time until it became dangerous. Anyway, bled all the brakes and made no difference so assumed it was the master cyclinder.
Replaced that with a new one and beld all four lines again (using a pressure based Gunson Eezibleed), and still got spongy brakes.
Basically doesn't 'bite' and the pedal goes almost to the floor. Even then, with full effort braking is decidedly 'dodgy' to say the least.
Any thoughts?
My thoughts are:
1) Could I still have air trapped in the system (is that possible with eezibleed?). I didn't bleed the master cylinder before installing, could that have air in it or would the eezibleed release that?
2) before trying with eezibleed I just used a system that had a one way valve to stop air going back and pumped the pedal. Didn't work (probably due to too much air in the system), but I read on one forum that you can rupture a new master cylinder by pushing the pedal to the floor. Might I have done this and need yet another one?
3) Could it be a problem in the calipers or rear cylinders (rear drum
brakes)
4) Might the rear self adjuster be wrong allowing too much pedal movement. (But surely that would still allow a good braking performance when it finally got to bite...which it doesn't)
5) Could it be the servo? But that wouldn't make the brakes spongy would it?
Can anyone think of a diagnostic procedure to try and track the problem down? Is it possible to check the calipers? (replaced rear cylinders as a
matter of course)
Cheers
Mark
The brakes on my 405 have always been a bit spongy and slowly got a bit worse over time until it became dangerous. Anyway, bled all the brakes and made no difference so assumed it was the master cyclinder.
Replaced that with a new one and beld all four lines again (using a pressure based Gunson Eezibleed), and still got spongy brakes.
Basically doesn't 'bite' and the pedal goes almost to the floor. Even then, with full effort braking is decidedly 'dodgy' to say the least.
Any thoughts?
My thoughts are:
1) Could I still have air trapped in the system (is that possible with eezibleed?). I didn't bleed the master cylinder before installing, could that have air in it or would the eezibleed release that?
2) before trying with eezibleed I just used a system that had a one way valve to stop air going back and pumped the pedal. Didn't work (probably due to too much air in the system), but I read on one forum that you can rupture a new master cylinder by pushing the pedal to the floor. Might I have done this and need yet another one?
3) Could it be a problem in the calipers or rear cylinders (rear drum
brakes)
4) Might the rear self adjuster be wrong allowing too much pedal movement. (But surely that would still allow a good braking performance when it finally got to bite...which it doesn't)
5) Could it be the servo? But that wouldn't make the brakes spongy would it?
Can anyone think of a diagnostic procedure to try and track the problem down? Is it possible to check the calipers? (replaced rear cylinders as a
matter of course)
Cheers
Mark