Brake fade why?

[runrabbit]

A couple of (simple) brake questions for the more mech minded.

Driving from Wgtn to Akld my brakes decided to fade at around Taupo. (Noting my car hasn't been used much in the last yr - ie 500km)

Pedal was getting softer every roundabout around the Taupo bypass road - having been going ok in the tighter stuff around the lake. I checked the brake fluid resevoir and its full and no signs of leaks.

Question 1

Is this caused by condensation/water or an air bubble? Seemed they faded with a bit of heat/harder use. Took it easy the rest of the way and I still have brakes now, but they don't seem as affective as they shld. (and they're just starting to slightly squeal).

Time for a flush and new pads

Could attempt myself - (tried it once b4) but tempted to just take it to a mechanic.

Question 2

Car is a standard 98 GC8 (no power mods) - is there any point looking at a brake upgrade? Even it was just better pads & dot5.1? Any brand suggestions, suppliers, or just stick with suitable budget/OEM replacements?

(Wish-list being 2pots, braided lines, bigger rotas etc - but not really needed or justifyable :)

Question 3

Im in Massey/Whenuapai - where can I get this done? Pitstop or find a private workshop/mech nearby?

..oh one more

Q4

Tein springs - worth it? I have ALK and rear sway bar to install asap. Brakes first tho.

Cheers

[Kiwi_Fozze]

I'd be swapping in some new pads, give it a flush and with new fluid give it a damn good bleed.

[madmike]

Put in some new pads and fluid.

If your managing to fade them on the road your either using them far too much or going far too fast..

[Joker]

Im betting Auto

[Kiwi_Fozze]

Auto rotors are usually a fair bit bigger than manuals, kinda reducing fade...

[runrabbit]

its a manual.

after reading a bunch of posts re brake pads both here and on Rexnet.com.au a couple of things stood out

a) dont sweat the small decisions

b) go for a 'better' upgrade rather than the 'best' upgrade (which was never on the cards anyway)

went to Repco for some Fedoro TS2000 - which they didn't have - and ended up with TWR. Should be adequate for a std street rex.

Discs machined and system bled. Will update in a few weeks wrt how the brakes are going.

[runrabbit]

grr ... new issue

took car on motorway and it vibrates at 100kph through the steering wheel. Only happened since the new brake pads/and machining last saturday.

Car doesn't shudder under braking, its only at high speed. Tho there is faint vibration at lower speeds as well.

is this likely to be a wheel balance issue (ie thrown a weight) rather than something to do with the new pads etc and the work done on the brakes. I did ring the guy who did the job and he said get a wheel balance, ie - not his problem.

annoying that it happened only after they had the car :-\

[Joker]

I have had similar feedback via steering wheel from a bulge in the rear tyre : true story therefore a possibility

what kind of brake disks? My cheeap ones warp pretty bad slowing from 180kph (ON the track) and you can barely hole the steering wheel its that bad

they are ok on the road mind you/feel cheep still/lack feel/bite

[funkytown]

if its doing it without being on the brakes its not the brakes wheel balance would be my pick. Did you put the wheels back on the car in the same place they came off?

[boon]

Just gonna throw it out there but go and check that all your wheel nuts are tight.... and that there's no play in the wheels.

[subi4snow]

 boon said:

Just gonna throw it out there but go and check that all your wheel nuts are tight.... and that there's no play in the wheels.

This ^^ now! A friend had a land rover which had some work done on it, got it back and felt wobble and decided was balancing and would be ok for a while...... Kept driving and didn't think anything of it until he saw his right rear wheel cruise past him the next day on the main road at 80+

Garage hadn't fully tightened wheel nuts after the work

If wheel nuts all good then I agree with the others and its most probably balancing

[runrabbit]

I took the wheels off to look for any probs. The shop had tightened the nuts super tight. Couldn't see any probs and put wheels back on.

Took for a drive and the vibration at motorway speeds seems to have almost disappeared. Tho now at lower speed 30-50km/h the steering wheel will 'slowly' vibrate. Feels like it wants to pull left then right. ???

Brakes seem fine. No dramas with them.

Will get a wheel balance once I get ALK on. Hopefully this wknd.

[runrabbit]

just to update,

alk fitted, had a wheel alignment - not to much drama there.

Balancing the front tyres found one had separated. Noticeably distorted when spinning on the balancer. So new tyre (make that two : for the front) and the vibration is all gone.

happy days (just minus another $500 )

[madmike]

So it was a bung tire a.... Well here you go.