I replaced my front disks about 5 months ago with some nice grooved and drilled ones by Tormoz as the standard ones were crap.

They must have warped as they started juddering slightly a couple of months ago under braking. After taking my Z up into the hills for a real thrash on sunday, I got in my car the next morning and now as soon as the brakes warm up they shake like hell.

It feels like the wheels are going to come off, anything loose in the car goes flying and I can't hold the wheel tight enough! Aaaargh! What have I done?

I heard it is a common problem with these cars but what causes it? If I replace them is it just going to happen again? They cost me £250 with pads!

 

I've got the same problem, if you are going to change the discs it may be best to get them heat treated. The calipers on the 89-93 Z32's are aluminium. Later models got iron calipers (I think to stop warping of discs or caliper, cant remember which).

Not sure if you can get your current discs heat treated. I think Johnny at Venom may be able to tell you more about that. Until then go easy on the brakes, think about how she'll stop in an emergency once the brakes are warm!

Laterz

Trev.

300ZX.CO.UK

 

When I first bought my import from a dealer in W Sussex I insisted that they replace the disks as they were obviously warped. This they did but they then warped again within a month. So either it was my driving or faulty installation. I went to a Nissan dealer (James Barr in Bishops Stortford) who were fairly helpful and agreed to get the disks skimmed and refitted. They informed me that it was very important to torque down the wheel nuts evenly on these cars as brake disc warp was often made worse by not doing so. That set lasted me about another 15,000 miles until they were badly worn but not warped. I'm now about 5,000 into my second set of standard Nissan discs and they're fine.

 

ok here is the lowdown on what i have found out.

 

i also fitted grooved discs and they warped on my 3rd lap of the nurburgring (and i was not driving quikly ask craig lol)

 

now apparently when the disc is new it has a substance on the outer surface of the disc (im not to sure what) and this may be the cause of the disc warping,

My dad, does all the brakes SERVICING for the porshe south africa and they will take (on the racing car especially) a new set of discs, do an instaltion lap and then scim the surface of the disc, this they recon solves the disc warping.

sorry for the long blab dont know if it will be of help, but does anyone know where i can have my discs skimmed? over here

 

I've got this too at the moment. Happened recently at a track day when I went pretty fast (and stopped pretty fast too).

 

Same thing with me, only happens after driving around for a bit and the disks get hot.

 

Sounds quite common at the moment on this forum. Maybe a group buy is in order for some nice heat treated disks???

 

Andy

 

i dont think the heat treat will work it definatly has to do with the caliper, and the skimming im quite sure of that.

 

One cause of disc warping can be leaving a parked car with very hot discs. They cool unevenly due to the insulation effect of the pads in the calipers. Some racing car types stop the car, jack it up and rotate the wheels by hand until the discs have cooled.

Kind of inconvenient up the high street though ...

 

Yep: Same problem here. With some very large & expensive AP Racing brakes - warped!! :-(

 

The car is due into the garage next week to see what can be done but the shaking is getting much much worse - its there from cold and is at is worse @ 60-80 mph.

 

The chaps at AP sent quite a detailed email about what could be wrong and a few possible causes - If you want me to post/email it then reply to me.

 

Cheerz

 

/\/\ark

 

Unless the discs are REALLY warped and are bashing the pads/calipers all the time then you should only feel vibration under braking. Vibrating at speed suggests wheel balance type problems to me. Check to see whether any weights have fallen off. (I always have the stick-on weights on the inside of the rim, then put gaffer tape over the top)

 

My vibrates only when braking. They are the standard discs which are quick worn done(evenly)..Will change mine to grooved and kevlar pads..Any one got an idea on prices and time to fit?

 

If you're an SE fan they do them, but they ain't a charity !

 

Looks like about £260 for the discs, £116 for the pads, plus fitting + VAT.

 

It's gonna be the painful side of £500

 

Couple of points :

 

1) Re Trey's post, I believe that it was only the Jap cars which had alloy calipers and that UK ones are steel.

 

2) I was seriously bothered about brakes and spoke to loads of people - the answer from those who had tried different things (and then used them hard) was that bigger brakes was the only way to go.

 

Dave

 

I know on the AP Racing site that they say if you have been driving hard not to apply the handbrake and park the car immediately as the pads clamp to the rear discs and cause a hot spot which can warp the disk. Also I have been told that the original Z wheel was designed to pull air over the discs as they rotated hence the the L/R markings on the rims

 

Nexus, you're right on both counts.

 

I was told at my first ever track day that you should never come straight in after your "hot" laps and park up. They always advised us to do a few slow down laps to let everything cool down a bit. Once back to the pits, you leave the car in neutral and the handbrake off (hard if the pits are on a slope!). They also recommended that you don't let the car stay stationary for too long and that you should get the car moving again (slowly) every now and then (I guess this is like what AndyP said the racing teams do by turning the wheel by hand to prevent warping).

You're also right about the Z wheels, they have been designed to cool the disks and are pretty good at it (according to a web page I once read). It is very important to get the wheel on the correct side of the car!

 

Andy

 

I now have the same problem. Replaced with EBC grooved discs and they are now warped. Vibrates at high speed and I can feel the pumping at low speeds. Mark, can you send me the email from AP. Cheers.

 

NE1 upgraded their discs and pads only without any probs?

 

Andy

 

I have SE machined grooved discs with Porterfield R4S pads on the car, they have been fitted since october and have had a fair amount of use without any problems at all. I also have the standard wheels and may be denefitting from the cooling?

 

Boy I wish this BB had a spell checker :-)

 

Z handbrakes clamp inside the drum of the disk, rather than the disk itself via the caliper, so this is a moot point on our cars.

 

the problem, as described already, is the heat soak effect of having the calipers surrounding a section of disk, slowing the cooling process down on that section, compared to the rest of the disk.

 

Thanks guys.

All your ideas apply to my Z.

I've got a '91 Jap import with non standard wheels so maybe I'm not getting any cooling. I ruined my disks last year up in the Lake District by taking my mate on a scary ride in the hills. Parked up outside a cafe straight afterwards and noticed large clouds of smoke coming from the wheel arches! Standard pads make good bonfires! Had to put the new disks on soon after that!

The other day went for a thrash in the Dales and parked up overnight, again with no cooling time. Next morning they are terrible.

Can you skim grooved & drilled disks?

Is there anything available to get more air to the brakes without a major body kit?

 

SE do some ducting type setup, as I'm sure do others. Don't know how effective it is though. Looks pretty low tech and easy to try out in the garage at home to me.

 

I had cooling docks (right spelling?) fitted by SE. Before, my wheels very litterally smoking after a drive. Now it's much much better. As I see it, cooling docks are a cheap and easy way of improving breaking. Cheers everyone.

 

I saw something very interesting on a Japanese website recently.

Apparently the brake-ducts of a Skyline R33 will fit the Z32 with some minor modifications.

Yup, you guessed it...they are larger then the standard ones on the Z32 and provide (much) better cooling.

As I understood from the website it seems it's a common upgrade in Japan.

 

this is the webpage for those that can read Japanese..

R33-brake ducts on a Z32

 

-Eric

 

 

I've had 4 types of pads on 2 sets of discs so far on my Import TT - The first set of pads came with the car and where Nissan OEM on standard Nissan OEM discs. Not great braking. Then I changed the pads for PAGID pads and got improved braking on Nissan OEM discs (same ones) then I was silly and got Lucas pads (£35 fro Halfards) but got new discs, crap braking with monter fade properties - avoid like plague - made for interesting heavy braking effect! Now I have EBC red stuff on the same discs - excellent stopping power at high speed, no fade. Not had any warping problems of any kind to report, but I have never thrashed the brakes and then stopped and left the car, I always let it cool down for the last mile - The heat soak theory sounds like the culprit to me.

 

Fitting time for pads = 1 hour max, for discs, add 30 mins extra per caliper, its quite straight forward really.

 

Oops - forgot to say Discs where £60 per disc and just standard looking vented discs, nothing special - disc wear seems normal and even.

 

I had a theory that jet wash strong detergent left on causes corrosion and a pad mark on the disc if you dont drive the car immediately after washing it. Thought the marks would fade with wear but they dont - wondered if the friction effect of the mark can cause similar effect to warped discs.

 

Mark..

 

Please send us the braking dit....

 

I have new EBC grooved disks no probs so far

 

Regardz