Ever since i've had my NB8A the brakes have never impressed me. I have bled the brakes about a thousand times, installed braided lines, greased the slide pins, and adjusted rear calipers so they are almost dragging. All of which has resulted in no significant improvement. I have noticed however, with the handbrake applied 30% the pedal feel is improved significantly. Also, when I push the thing that floats inside the master cylinder, black misty stuff comes out.
After all this I think the master cylinder may need replacing, would you blokes agree? Any advice would be appreciated. Currently running QFM HPX Brake Pads
Soft Brake Pedal
Moderators: timk, Stu, zombie, Andrew, -alex, miata
-
- Driver
- Posts: 27
- Joined: Sun Nov 21, 2010 11:29 am
- Vehicle: NB8A
- Location: Sydney
- Regie
- Speed Racer
- Posts: 4259
- Joined: Thu May 15, 2008 3:02 pm
- Vehicle: NC - V8
- Location: Sydney
Re: Soft Brake Pedal
sounds like the master cylinder or brake booster has a leak, probably a hole in the diaphragm inside. you change them both as a whole anyways
MY07 NC, Mazdaspeed Body, Ohlins, Full GWR Exhaust, 17x9 RPF1's, 4.1FGR and lots lots more
-
- Forum Guru
- Posts: 4897
- Joined: Mon Apr 24, 2006 7:27 pm
- Vehicle: NA8
- Location: Moruya, NSW
Re: Soft Brake Pedal
The seals around the pistons in the master cylinder are deteriorating. That's the black misty stuff you see - perished rubber.
As soon as I see that starting to happen on any car of mine I replace or rebuild the master cylinder. Soft pedal then goes away.
As soon as I see that starting to happen on any car of mine I replace or rebuild the master cylinder. Soft pedal then goes away.
’95 NA8
-
- Driver
- Posts: 27
- Joined: Sun Nov 21, 2010 11:29 am
- Vehicle: NB8A
- Location: Sydney
Re: Soft Brake Pedal
Cool cool, this has been helpful. I'll look into a new one/rebuild.
- bruce
- Speed Racer
- Posts: 7707
- Joined: Fri Apr 25, 2003 11:00 am
- Vehicle: NA8 - Turbo
- Location: Victoria
- Contact:
Re: Soft Brake Pedal
On an aside, my gasket around the reservoir cap was deteriorating. This caused misty rubber to dirty my fluid.
Return to “MX5 Wheels, Suspension, Brakes & Tyres”
Who is online
Users browsing this forum: No registered users and 121 guests