Mx5 - new pads/fluid: long pedal

[Zac]

Just fitted full set of Axxis (I think are DBA Ultimates) pads and dot 4 fluid.

Braking and bleed seem fine but the pedal is a bit 'long', ie I'd rather the braking pick up sooner in the pedal's travel.

Do I need to adjust the pedal-master rod or something? Or have I not tightened the rear pistons in far enough?

[Cameron_Datto]

Have you bedded the brakes in ?

[Zac]

I haven't done a large amount of miles on them yet.

Definitely working fine, I'd just like the brake to start a bit earlier in the pedal travel.

[Babalouie]

Did you screw in the rear pistons or did you just push them in with a clamp? Cost they're meant to be screwed in. Also after fitting the new pads, you adjust them back out again with an allen key going into the back of the caliper, did you do that?

[Zac]

Yep I did all of that. Then I adjusted the pistons until the pads touched the disc then backed it off 1/2 turn or so. Handbrake is working fine.

[bigmuz]

Wait till they are bedded in and give them a quick bleed. The angularity of the pad surfaces and the paint they are smeared in add up to give you a long pedal initially. Once they have a few cycles and everything wears parallel then you should get your pedal back.

[dattoman1000]

Axxis of evil.....cheap ass pads....Bendix budget line

[Zac]

:( All the Mx5 guys reckon they're great. If they're crap they'll be destroyed after a couple of track days.

I'll rebleed them this weekend. They've done about 150 miles now.

[260DET]

Yeh I thought that Axxis pads were Bendix Ultimates rebranded for export, a set of them came with the US Stoptech brake kit for my car. I'll argue forever that in my experience Ultimates are a decent high performance pad.

[CT]

:( All the Mx5 guys reckon they're great. If they're crap they'll be destroyed after a couple of track days.

I'll rebleed them this weekend. They've done about 150 miles now.'

No we don't!!!!!!

Ultimates are average in track conditions - very, very average.

[Zac]

I'm only a track day guy anyway, not a racer, so I need to retain some road performance.

What fluid do you recommend then? I've been told to get Motul RBF-600.

260det, yeah mine had 'DB Ultimate' stamped on the back too.

[CT]

Elf HTX115 fluid > Motul (motul is still good fluid though) and get a decent combo pad like a DS2500 Ferodo or perhaps a Hawk Ceramic or HPS, Porterfield or Cobalt from the USA. Check flyinmiata.net or good-win-racing.com

All of the above pads far exceed the performance of those ultimate piston spacers for a dual duty track car. Don't forget that many racers start with dual duty cars......been there, done this for many, many years.:)

[Zac]

OK while we're here, what about braided lines? :)

Sometimes my pedal feels as though if you push it hard enough it reaches a physical 'stop', which is slightly disconcerting but I have never felt the 'stop' while moving. Is there some adjustment somewhere that I have missed?

I think I need to change one of the rear calipers anyway, appears to be leaking.

[bigmuz]

That 'stop' is what it should always feel like.

The problems are;

moisture in fluid
Air in fluid
Flexible hoses
Reaction disc
Flexible calipers
Flexible firewall.

HTH

When we had the Formula Ford hillclimb car setup right the pedal was like a brick wall that was only pressure dependant and not travel dependant. Maybe 1/2 inch of travel and then rock.

[Zac]

It just feels not like any other brake pedal I've had before. It stops fine, no danger here or poor work by me. I don't think there's anything wrong with it, I'm just getting picky :)

[jezza323]

when i upgraded my calipers to a slightly bigger piston the pedal dropped a little, so i installed a master cyl brace, tightened it up, and it made me much happier. dunno how mx5's are in that department though.

[CT]

They do like an MC Brace and braided lines too - but if you've past bigmuz's checklist, the slider pins are lubricated and the pads correctly bedded, the pedal shouldn't be long.

[Cal]

If you buy one of those cheap arsed strut braces off ebay it will give you somewhere to mount a master cylinder brace. Mine consists of a bolt with a rubber door stopper looking thing over the end of it, screwed hard up against the master cylinder. Works a treat.