Disc Machining

[Cuppa]

Before we leave Broome I want to fit the 'Yellowstuff' EBC pads I bought before leaving home to replace the 'Greenstuff '6000 series I fitted together with then new RDA Dimpled & Slotted Rotors. That combination of Pads & rotors, whilst expensive has been worth every cent & I/m now hoping that the Yellowstuff pads will be a further improvement.

EBC recommend that discs be machined anytime new pads are fitted & I'm happy to go along with this.

I'm aware that rotors can be machined whilst still on the car or having been removed. Apart from the extra cost of taking discs off is there any advantage/disadvantage to one way or the other? Which is best & why?

I'm not sure whether Broome will offer the choice but it would be good to know before I go looking. I've had it suggested that it may be just as cheap to get new rotors, but with freight costs I suspect I'd be looking at $350 + & doubt machining would cost that much.

[garett]

personally id go with machining on the car. machining should be much cheaper than new rotors. I had those rotors with Bendix pads on the wifes mazda 323, I got whinged at, it stopped too quick...
either way you machine them if done correctly they should work fine. have had some issues using machined rotors, they were machined cos they warped they then warp easier this may be restriced to ford falcons though

[pearcey]

G`day Cuppa. OK the cheapest way is on car, but the blokes doing the job need to know what they are about. first up they need to check that the bearings are OK then adjust them so there is NO play, then machine the disc and readjust the bearings after the job is done. NO play means the disc will spin true and machining is accurate, if there is a slight bit of play the machining can be inaccurate. Off Car, As the disc on the Patrol are fitted to the back face of the hub a complete disassemble of the hubs is what is needed ,ONE advantage is that the bearings will, SHOULD be cleaned and repacked also the seals should be replaced. Cost wise $500 would not surprise me if it was done correctly. Hope this helps. Pm me if you want my phone no. Stay safe.

[Bidja]

No first hand experience with m/c rotors on vehicle. My concern also is ability of the rotor to run true (no play) on bearing/axle assy. Rather turn up on lathe to eliminate these variables.

To replace pads you need to swing caliper out away off the disc/rotor so not much more work involved to remove rotor for m/c or replacement. ABS sensor to be removed(if fitted) before rotor removal. Yes clean or replace with new bearings/seals.

Did same exercise DIY recently, was thinking machining or new, local mechanic I know recommended new rotor as there could be heat spots in rotor face and considering the low cost of new rotors today, advised go new. You can only do the cost and lead time caparison yourself to decide.

Personally, if the current rotors look OK and no wear lip evident, I would just put the new pads in (your choice). Decision will be influenced by cost and who is doing the teardown/turnaroud (shop or yourself).

[mudnut]

I have found that it depends on the condition of the rotor, as to which way I have gone, in the past. If the rotor surface is clean and there is no noticeable run out , grooves or warping, then I just replace the pads. Have done so quite a few times and have had no problems.

[Cuppa]

Thanks for the info folks.

Have had a bit of communication with the workshop I've used previously in Broome (& whom I found to be good ). Initially he said Dimpled/slotted could not be re-ground but subsequently clarified this saying that they could be done on the radial grinder he has, except he doesn't have the necessary adapters. I think he uses it for clutch plates.

The following article I found online makes me think I would want to have a lot of confidence in a machine shop to know the job was being done right whatever they used to do it.

screenshot_45.jpg

The RDA slots are curved, not straight as in the article & I'm guessing this wouldn't make the job any easier.

Getting them machined on the car does not sound like a good option to me, even if there were someone in Broome who could do it.

At the sort of money Pearcey mentioned I'm thinking I have two options.

A) Just replace the pads myself on the existing discs
or
B) buy new discs (which I can get a pair, same as I have, online & delivered to Broome for $176) & fit them & the pads myself.

First I need to see how much pad thickness I have left. It is possible I *might* have enough left to get us across to Cairns. Allowing for a few 'deviations' along the way I reckon I'd want to be confident of getting another 8- 10,000kms out of them. I looked at them before we left Vic & thought "I'll have enough to get us to Broome" & it may be I still have plenty left.

Issues I have here are not having any hard standing or undercover workspace, & sitting out on sand among the ants & hot sun and/or pouring rain ..... is not conducive to pulling out the hubs etc if I don't need to.
If I can get across to Cairns/Tablelands first, there is probably a better chance of finding somewhere suitable to work, but we have a lot of Kimberley & Gulf country in between, possibly Arnhem Land too.

I can carry the replacement pads with us to fit if needed, but given the pads cost more than the discs(!) I do feel a bit reluctant to put them onto the old discs as is unless absolutely necessary.

Soo... (Bear with me, I'm thinking this through as I type) ........ I think if there is a reasonable chance of getting across to to the east coast with the existing pads that's what I'll do, & then replace discs & pads over there myself (I fitted them previously myself) - I have the tools to do it (except for torque wrench), but if it looks like they need doing before we leave here I'll get replacement discs & pay for the job to be done unless I can find a suitable place to do the job myself. Chances of that are probably not high though.

Was going to jack up the car at first light this morning to look at the pads, before it got hot & before the ants woke up, but half a termite affected tree falling down over the top of the kitchen last night took priority, so maybe tomorrow morning. Evenings are less good - light is fading & ground is hot & it's the mozzies favourite time of the day.

[mudnut]

If you find that the pads are too thin and the rotors too far gone, why not grab a cheap as set of pads, and whack them in for the journey? Just drive accordingly to the reduced performance.

[Bidja]

X2 with mudnut.
Never used a torque wrench for this job..

[Cuppa]

If you find that the pads are too thin and the rotors too far gone, why not grab a cheap as set of pads, and whack them in for the journey? Just drive accordingly to the reduced performance.

Not an unreasonable suggestion but not over keen mainly because in my opinion the standard brakes (discs/drums) were woefully inadequate to the point of being dangerous when fully loaded - which of course we are whilst travelling - & that was without the additional weight of the Tvan pushing us. Overshooting the turn into our road at home because the standard brakes would not pull me up was an experience I don't wish to repeat anywhere. I don't know what made the biggest difference the dimpled/slotted rotors or the EBC pads - all I know is that together they transformed what I felt to be an unsafe vehicle to a safe vehicle. When we leave here we are headed into country & tracks which may 'expand my comfort level'. When descending the rocky steps of the Munja Track, for example, I want to have as much confidence in my brakes to pull up & hold both car & van as possible. Bottom line is I don't know how cheaper pads on those discs would perform.

The 'Journey' could well be over a period of 6 months or more & it would be a real bummer to be in the middle of a long held dream but having to restrict what I do & where I go because of potentially poor brakes.

Re the torque wrench Bidja - if I had to, as temporary measure, I'd do without, but would feel far happier torquing bolts correctly in such a critical area as brakes. In the absence of a torque wrench 'as tight as I can' would likely be the 'figure'.

[Bidja]

The 'Journey' could well be over a period of 6 months or more & it would be a real bummer to be in the middle of a long held dream but having to restrict what I do & where I go because of potentially poor brakes.

Re the torque wrench Bidja - if I had to, as temporary measure, I'd do without, but would feel far happier torquing bolts correctly in such a critical area as brakes. In the absence of a torque wrench 'as tight as I can' would likely be the 'figure'.

Guess you have to remove wheels have a good look at your pads/discs and make your own judgement there. If while braking at speed 60-80 kpm down steep decent into corner and front end feels stable with no shimmer the disc are most likely fine. So get your preferred new pads and take them with you as spares if current ones have good 8mm.

Fair call for objective measurement with caliper bolts and is an improvement on my subjective size 10 lbf-ft. Personally, I rather preload wheel bearings by feel.

Your trip must be full of pleasures, my vegies would not survive my absence, maybe one day.