Rda Rotors Issue

[SargeRX8]

Hey all,

My mate and I both have R33's so we bought some RDA slotted and dimpled rotors to replace worn out stock/dba parts. They settled in nicely but about 5 - 6 months later my set started developing a shudder when braking which feels like its coming from the front right. Its pretty violent slowing down from anything above 80 but happens down to as low as 40. My mates car is now doing the same thing.

I would barely call my self an aggressive driver. I don't ride the brakes either. I've had skylines for the last 6 years and all cars had DBA's on them. This was the first time trying RDA out and I feel I made the wrong move. Has anyone else used these rotors and had issues or not had issues?

I am using these with Remsa pads all round.

Machining will get the surface true again but if the disc is warped, I'm better off just buying a new set of rotors. RDA give a warranty/guarantee but their customer support simply pushed all the blame on me, my car configuration, my driving style, everything me.

[niZmO_Man]

That's a bit crap. I never had issues with RDA, but haven't bought discs off them in over a year.

[GTRPSI]

Im a registered RDA agent, we sell thousands of sets of the dimple drilled and slotted rotors a year and a really high number to Skyline owners.

Have a look here, there are a few TSB's that discuss it.....http://www.rdabrakes.com.au/page/technical.aspx

We run them on all our cars, my sons had them glowing red hot (a automatic warranty rejection) that many times and never warped one, even in our GTR.

Most common issues are warped hubs from tyre shops over tightening wheel nuts or dirt not cleaned off the hubs before fitting them so the rotor runs crooked, usually takes 3-5000Km to see the shudder in those cases.

Most common Skyline issue has been a piston sticking in the caliper, seen around 4 of them with local workshops who called me to show me, once the calipers were rebuilt problem never returned.

Some pads also like to cause disc thickness variation (we find bendix GCT pads the worst), again not a rotor issue.

Can hardly blame the rotor for the above....

Here is a picture from my Falcon after testing for 60,000Km, you can see the blue heat marks from the amount of abuse they got, also note below that i had Apexi cross drilled rotors on the GTR and they all cracked from a few sessions at Winton, when we put the RDA rotors on the GTR and no more cracking, lap after lap, overheating them...

You also have a warranty on them covering manufacturing defects, if there is a build fault with the rotors its covered.

[junkie]

I have them on the front of the 35, probably done 20k km so far, no issues. Run them with ceramic Girling pads, so can hear them rubbing against the pads lightly at low speed with windows down, otherwise pretty happy

[Duncan]

I wouldn't lose a second's sleep about it. Check the run out and machine them flat, and off you go again.

[SargeRX8]

Prior to installing them, the hubs were cleaned with a wire brush and everything was good to go. When I installed them I checked runout and it was all within spec then everything was put back together. The wheels were torqued with a torque wrench, I never use air tools or electric tools to tighten wheels.

Duncan, will machining them bring them true again or is it a bandaid fix for a faulty rotor or underlying issue? I'm thinking while I am at it I may as well rebuild my calipers if its an easy job.

Does it matter if I use genuine/after market brake seal kits?

Edited September 13, 2015 by SargeRX8

[GTRPSI]

Firstly, before you do anything, check them for cracks, hot spots and the amount of wear on each face.

Look at each face from inside where they contact the hub, is there a even mark all the way around or dots/marks pointing to high spots?

Bearing packs tight with no play?

Uneven wear or discoloration on any face being worn slightly more then another points to a sticking caliper.

Once you have established where your issue is from, then machine the rotors on car, not off, its far more accurate.

If your caliper is sticking, in most cases its a rusted piston on the skyline sumitomo calipers due to lack of bleeding through the years and water being absorbed by the brake fluid, best to replace the faulty piston (rather than polishing the old one) and use a new seal kit.

Aftermarket seal kits such as TRW are fine and of high quality, stick with known kit brands if not going OEM.

If your rotor is faulty there will be a obvious crack or casting defect running through it, as mentioned rotors deform for a reason.

Edited September 13, 2015 by GTRPSI

[GTSBoy]

As usual, I must point out that rotors almost never "warp" and such shudders and carry on are almost always uneven deposits of pad binder material onto the rotor. Give them a rub with some sandpaper and see if it goes away.

[dan.1337]

  On 13/09/2015 at 11:40 AM, SargeRX8 said:

Does it matter if I use genuine/after market brake seal kits?

I would personally only go OEM

[SargeRX8]

I will try hit them with the wire brush my self. There is no burning or discolouration at all. They look pretty good. If this is no dice I will get them machined and see what the go in.

In regards to brake rebuilding, from what I've seen there is usually a lot of wear to the piston it self. Would it still help to do a rebuild without changing the piston?

[GTRPSI]

Pistons are of a harder material than the calipers themselves, are you sure your pistons are actually worn?

I usually see the pistons rusted, pitted and full of crud.

If the pistons marked where the seals make contact, replace it, they are around $50 each aftermarket off the top of my head last time i checked.

http://stores.ebay.com.au/performancecarpartsonline/_i.html?_nkw=sumitomo+piston&submit=Search+Store

[SargeRX8]

I have no reason to suspect my calipers are an issue, but I might as well service them. Going off what I've seen online there is a chance mine could be pitted simply because of the age.

[Duncan]

  On 13/09/2015 at 11:40 AM, SargeRX8 said:

.....Duncan, will machining them bring them true again or is it a bandaid fix for a faulty rotor or underlying issue? I'm thinking while I am at it I may as well rebuild my calipers if its an easy job. ...

It may well be a band aid....but even if the issue comes back machinging is a cheap bet. There were more detailed responses about other areas it's worth checking.

But overall, I guess I'm saying having to machine rotors every now and then isn't a big deal, even if there is an underlying cause. The exception would be if it goes out of round again quickly in which case I'd check it our more thoroughly

[MrStabby]

Dont forget to check radius rod bushes...

[SargeRX8]

  On 17/09/2015 at 11:10 AM, MrStabby said:

Dont forget to check radius rod bushes...

I've got those rose bush things up front, are they a bad idea? Should I go hardrace aftermarket or stick with factory and new bushes? I've got issues up front with worn bushes as I am having some severe clunking and clatter noises up front when reversing and going forward and turning. When at full lock too my left wheel is like thunk thunk thunk. I didn't think this could affect the rotors though since the rotors will be flush to the hub and the hub would be flush to the caliper etc. Mind you though, these clunking issues started after the vibration issue.

Edited September 17, 2015 by SargeRX8

[MrStabby]

The tl;dr version is rose joints work better, but don't last and are not legal for street. If you're mostly street and the rose joints are shagged you're probably better off going for something like the hardrace bushed adjustable radius rods. Might as well check all the ball joints and other bushes at the same time and fix anything thats stuffed.

That stuff doesn't affect the rotors, but the whole hub assembly gets a bit mobile and can cause shudder that feels pretty much the same as rotor shudder to me.

[GTSBoy]

Note that rose joints on radius rods would have to be very very stuffed to allow much movement. The noise they generate would annoy you to death before they got that bad.

[SargeRX8]

I've ordered eyelet bushes for my HSD coilovers. I'm essentially on metal/metal contact. I quite likely need new radius rods as these are about 3 years old and have never been greased up since initial install(lol). What else should I look at at the front while I am there? Will shaggered sway bars cause clunking noises? It gets so bad at full lock sometimes it feels like my wheel is going to fall off sometimes there is that much play. I can't physically(by hand) put enough force to feel play but when the car pushes its weight on the corner, you know there is an issue. There could also be some bush walking going on there but again I don't know. I will order some hard race parts. I've just recently installed solid camber adjustable camber arms too which I had adjusted at the local shop. Fresh rego on the car I have about a grand I can throw on the front to rectify any issue and eliminate this shudder.

[GTSBoy]

Just about every movey bit. Upper arm bushes, lower arm bushes, ball joints, tie rod ends, even the bearings in the uprights. ARB bushes as you suspect will cause noise under dynamic loads, but they shouldn't cause shudder under braking because they don't really do anything to control the position of the wheel.

[hardsteppa]

I can't believe you're saying you have that many issues in your suspension but yet you're putting the shudder down to an issue with the rda rotors? Come on...