HSV 6.0L brake surge

[VZSS]

Hi,
Just seeing if there is any brake guns on here that could give me some helpful advice, I have a VZ SS, its a LS1 but has upgraded brakes to the HSV 6.0 liter brakes with slotted rotors, I have had both front and rear skimmed on separate occasions in the last couple months, rear where only done about three weeks ago, front about a month before that and probably a month before that again, Now the front discs are sending a surge to the steering wheel when braking lightly at around 60 KMPH again, not sure what to try next as the longer I leave it the more damage it does to the bushes etc in the front end, anyone else had this problem?

Cheers

[gslrallysport]

3 Questions:
- What pads are you running?
- How were they bed in after the rotors were machined?
And most importantly....
- When where the wheel bearings checked last?

[VZSS]

Thanks for the reply,

Pads- not sure but will find out Monday but I can say there chunky and messy as in they keep the mags dirty.

Bed in? Ill have to ask about that too

With the wheel bearings, not sure what is involved in checking them, would you need to dismantle the hub? Or could you do it just by jacking the wheel off the ground and checking for any excess movement? The car has only done 60'000 KMS.

[Surfwagon]

I have found that as the brakes have gotten bigger over the years so has this very problem seemed to become more common after machining.
Maybe because the large rotors are quite heavy in std form the machinist isn't getting it on the machine perfectly straight.
I personally know of 2 cases where guys did a pad change (same new pads as what they took out) with a rotor machine and ended up with surging at low speeds, throbbing as one guy put it.
Anyway they checked everything they could at home like did the wheels lose any weights, did the hubs look and feel good, were the hub mating surfaces all clean, even used a gauge to measure run out on the discs, all seemed good but still throbbed.
Both bit the bullet and put new discs on, one with DBA5000 discs and aluminium hubs and the other RDA's both with no more throbbing.
My money goes on machining of the discs as the cause.
But as GSRally said, were they beddded in properly although these days not many people know you should or even know how to bed in brakes and doesn't seem to be a major problem among the masses.




So my

[VZSS]

Got quoted a EST $2000 today for front disk and pad replacement, that's with the two piece rotors, they said the size was a bit larger because they are Skaife specials, possibly from this car.

Holden Special Vehicles Senator Skaife Signature Z Car Research - CarPoint Australia

How does that price sound? Pretty keen to get it fixed...

[Brenah]

$2000??? Serious
Are they Brembo"s or something? That's steep.

B

[dijm8]

$2000??? Serious
Are they Brembo"s or something? That's steep.

B

thats cheap for brakes, more serious kits start from 5-10k

[Brenah]

What rotors and pads?
Are you talking about a FULL brake package? Well yeah $2000 is cheap. But the OP is after rotors and pads only.
Correct me if im wrong

B

[VZSS]

Its just for the replacement of the front pads and rotors with a pad specifically for street use, heavy duty pads that have been tweaked for street use with out the squeal, the rotors are the premo ones, two piece, cant remember the brand, RDA or something, they are getting more available options tomorrow so should get some more feed back, the two piece rotors sound appealing though, this seems to be a common thing

[Surfwagon]

thats cheap for brakes, more serious kits start from 5-10k

But he is only talking pads and rotors for front replacement, not a whole new brake kit.

[gslrallysport]

Its just for the replacement of the front pads and rotors with a pad specifically for street use, heavy duty pads that have been tweaked for street use with out the squeal, the rotors are the premo ones, two piece, cant remember the brand, RDA or something, they are getting more available options tomorrow so should get some more feed back, the two piece rotors sound appealing though, this seems to be a common thing

They won't be RDA as RDA don't do two piece rotors. They'll be DBA 5000 Series slotted, which even our price is $627 per rotor, so yes, they're expensive suckers! Pads I'd go QFM HPX, which are a Bendix Ultimate equivalent, but low dust and rotor wear, $119 for the set. So all up for a pair of DBA 5000 Series two piece rotors, and a set of pads, $1373.



Otherwise RDA do make a single piece rotor replacement for the front, which are $559 for the pair in slotted.

[dijm8]

But he is only talking pads and rotors for front replacement, not a whole new brake kit.

my bad...thats expensive then

[Surfwagon]

my bad...thats expensive then

You're right it is expensive for front only even though it is for top of the line 2 piece rotors not like GSL's price of $1373 incl quality pads.
Also it appears the OP has VZ Ap's fitted to the car which is a good street setup for VT-VZ's.
I will be looking 2 piece rotors when my AP brakes need pads and/or rotors.

[VZSS]

They won't be RDA as RDA don't do two piece rotors. They'll be DBA 5000 Series slotted, which even our price is $627 per rotor, so yes, they're expensive suckers! Pads I'd go QFM HPX, which are a Bendix Ultimate equivalent, but low dust and rotor wear, $119 for the set. So all up for a pair of DBA 5000 Series two piece rotors, and a set of pads, $1373.



Otherwise RDA do make a single piece rotor replacement for the front, which are $559 for the pair in slotted.

Would you know if RDA have them in this size?

http://dba.com.au/products/DBA52018BLKSL

[gslrallysport]

Not as a two piece rotor they don't, but as a single piece slotted rotor, unpainted, they're $559 for the pair.