Grabby Brakes

[TTT]

Recently bought a 2001 NB8B.
The previous owner put new discs and pads recently (confirmed by workshop who did a quick inspection for me)

I haven't had a chance to start pulling things apart to investigate or know where to start but the brake pedal works like this..

Slight touch and you feel it slow down a little, hear the front pads squeak (left front seems to touch before right front)
About 1mm more pedal and it really slows down.
Another 1mm and it tries to put me through the front window.

Where to start?

[Magpie]

What car have you dríven before?

[TTT]

ah.. about 23 cars now I think..

Going backwards..
NB8B
2003 wrx
NA6
R32 GTST
then it goes, Subaru, Nissan, Subaru, Nissan about 4 times
then some older stuff.

It's really not normal.
Brake fluid doesn't look to have been changed in a while so I figure I'll start there...

As an example, when it gets to the stage where it really stops hard, there is still plenty of pedal left to push...
It's almost like it's completely clamped on the discs in the first few mm of pedal

[Magpie]

Slider pins possibly. If changing the fluid you may as well check these as well.

When I did my calipers a while ago I found this. I make sure every few months or before every second track day I grease the pins. Another lesson is to have some spare slider pins on hand in case they need to be replaced and nothing is open.

[TTT]

Noted. thank you.

[smy0003]

Does it get better/worse as the brakes warm up?

[TTT]

Worse..

The first braking point from leaving the house is less touchy than after a few stops.
I'm not even talking high speeds here.. like from 40 or from 60-80.

Still driveable but the first time you drive it, you definitely realise how sensitive they are when it tries to do this at first touch of the brakes

[PeterB]

What brake pads are they ? Sound like track spec pads if they bite that hard.

My Carbotech pads road/track pads operated much as you describe. Grabbed early, squealed and were dirty, but were great on the track with temperature in them.

If there are no other mechanical issues you may need to go to a softer pad ?

[TTT]

I'll double check over the weekend.
I thought previous owner mentioned Hawk but can't be sure now.

[93_Clubman]

From what you've said it sounds like the issue is the front brakes, but if you think rear brakes are contributing then see Failure Modes & Note from D. Macfarlane in the following: http://www.miata.net/garage/ebrake/index.html

[TTT]

To test if the rears are an issue, I used the hand brake to slow down from 60 and it seemed fine.
As in the more I pulled the hand brake, the more it slowed down as expected.. The amount of pressure applied by the rears was as expected from the amount of pull on the handle.

So I don't think the rears are causing any problems here.

[PeterB]

I'll double check over the weekend.
I thought previous owner mentioned Hawk but can't be sure now.

Hawk HP plus and Hawk Blues are good street/track pads that may cause the symptoms noted. Such track orientated pads also need to be properly bedded in. On my NB8A I have one set of rotors/pads for the street and a 2nd set of hawk HP+ or Carbotech XP10 and rotors for the track.

If you can get your hands on a 2nd hand set of standard pads you could give them a try and see if the issue goes away.

[project.r.racing]

Bleed the brakes.

[bear2230]

Exactly the same symptoms as I have with QFM A1RM. Good stopping but squeely and a little grabby.

Changed them back to the standard pads with the backing plates and now they are lovely again.
http://www.mx5parts.co.uk/front-pads-ge ... p-838.html

Richard.

[TTT]

Still haven't had a chance to check..

Spent 3 hours on it with a RO Polisher as that annoyed me more

I've got another 2 hours to go on the paint and then I can get on to the maintenance stuff..
I've bought:
engine oil and filter
gearbox oil
diff oil
brake fluid
spark plugs
exhaust

I've also borrowed a power bleeder kit from a friend..
Will work out how to use it and do the brake fluid

Will get around to it soon.