kenaston99

Are there certain torque specs I need to do for calipers and brake rotors, or just tighten until snug? I've looked everywhere and couldn't find anything on how many lbs of torque to apply for everything.

05ls430518

iTrader: (1)

hand tighten carefull with the calipers its all aluminum so dont he-man them and strip everything.

kenaston99

That's what I figured, thank you for the clarification!

rkw77080

Front caliper bolts should be torqued to 81 ft-lbf, and rear caliper bolts, 58 ft-lbf.

kenaston99

where did you find that diagram? Service manual? I'm very OCD so if there is a specific number I need to apply to something this would be the case

rkw77080

Those pages are from the 2004 LS430 Factory Repair Manuals.

Johnhav430

Agree with hand tightening, also be sure to replace those caliper bolts, everyone recommends to do so, and the official procedure is such.

I bought these, but waited for a 20% eBay coupon to take a few dollars off. It's tempting to reuse, but why not do it right...

https://www.ebay.com/itm/LEXUS-OEM-F...item3612ddd471


edit might want shims too if they are not there (seems like shops toss them)

rear

https://www.ebay.com/itm/LEXUS-LS430...sid=m570.l1313

front

https://www.ebay.com/itm/GENUINE-LEX...LH_TitleDesc=0

rkw77080

Please also note that Lexus classifies the caliper bolts as "non-reusable".

One of the reasons for this is that the brake caliper experiences extreme temperature swing during normal operation. Mating parts made of different materials (i.e. different thermal expansion characteristic) will either fused/welded together or work themselves loose. In our case, the Lexus engineers used aluminum alloy bolts to match thermal expansion characteristics with the caliper and turn knuckle. As one of the softer metals, these aluminum bolts are stretched every time you torque them down, and if done repeatedly, the bolts become weakened.

jayclapp

Good post with important information. I have noticed that on this forum it is quite often that people doing brake jobs seem to think that "a bolt is a bolt" and use whatever they can find or reuse. Same thing with rotors, where pads are changed with no regard to checking the runout and turning the rotor if needed.

Johnhav430

This is from observation....changing rotors has been an upsell at the tire shops/muffler shops of the world, where it could potentially drive a $99 per axle brake job to $300+ (when they are using rotors that would cost us $20 ea at rockauto, even less to someone in the trade). I think people got turned off and somewhere along the line a "pad only" job came about.

On the other hand, until recently, cos. like BMW only changed pads/rotors, never pads only.

At the end of the day, by the time pads need replacement, almost all rotors are going to have a lip where the pad has swept the rotor, and then the next time pads only are done, the area gets smaller and smaller. New pads, old rotors, is not optimal, but it "passes." imho, at a dealer or muffler shop? Do pads only. If you are DIY? It's your own labor, may as well do the rotors. They are cheap now. I got centrics for $27 for LS430 backs. Maybe I am kidding myself but to the touch, they look as good as Lexus OE, which don't look that great to begin with. Compare to GM OE or BMW OE, which are baked in an oven with nitrogen (as are Jeep Chrysler etc.)...

nc356

iTrader: (1)

Now I feel just awful I'm on my original rotors, never turned, at 292,000 miles.
OEM pads always; I forget the measurement, but still plenty thick per the number cast in the rotors.

kenaston99

I absolutely agree with everything you said. If you're going to do the pads you should just do the rotors are the same time and save yourself some concern and time. I didn't know the caliper bolts weren't reusable, that's good to know. I buy everything from Rock Auto, but I make sure to buy OE quality. Thank you everyone for the information you've provided!

Johnhav430

I used to think this way, but admittedly have swayed over to the BMW side. Meaning, my decisions were based on marginal benefit > marginal return, or no dice.

Germans ignore the above and simply want things to be right, and the best. hence never pads only, always pads/rotors together, even when maintenance was free and it was at their cost.

But now they've eliminated brakes from free maintenance so they do offer a pad only job since most people leasing a car are upset if they are told they need to pay $800 or $2000 per axle for brakes (M cars are the latter).

I noticed that when I recently did my wife's rear brakes on her GM, I said let's discard the old rotors even though fine, AND, let's replace the pads too. Uncle looking over my shoulder (his lift) said these pads are new? I said yeah (did a pad only < 12 mos. ago), but let's just use the new pads since the rotors are new. I did keep the used pads, maybe I put them in next time esp. if rotors end up scored/embedded...