Time To Do Rear Brake Job

[AZ Mike]

Quick question for brake do-it-yourselfers: when replacing brake pads, is it necessary to use new shims and caliper hardware? I saw somewhere that this is "recommended". Personally, on other cars, I have only changed the pads and re-used existing hardware without a problem.

[jcrome04]

You should be able to get calipers loaded with pads and ready to go from somewhere.

I personally would try to stick with OEM, or at least matching pads and rotors.

[AZ Mike]

Sorry, I probably wasn't clear.

I will replace worn pads with OEM pads and am perfectly comfortable with doing so. My question is concerning the shims and the retaining hardware; I read that it is recommended that it is replaced with each pad change. I was just curious what those on the board think. I.e., do you re-use existing parts, or replace shims and retention hardware with each brake job?

[TexasLexus94]

I always use the existing hardware including the shims with a little dab of new noise stopping grease. Never even thought about not using those existing clips that position the pads in place. No one agrees with me, but I always install new rotors too. That way, the rotors and pads are an exact match-I've had mixed luck with ground down rotors. New front rotors and pads for my 94LS cost $105. Not OEM, but they work superbly. Best of luck.

[Depot]

They told me at Pep Boys today that the noise stopping grease isn't necessary with pads that use shims. The grease I did look at said do not use with shims, so maybe he was right. Dunno...

[curiousB]

Sorry, I probably wasn't clear.

I will replace worn pads with OEM pads and am perfectly comfortable with doing so. My question is concerning the shims and the retaining hardware; I read that it is recommended that it is replaced with each pad change. I was just curious what those on the board think. I.e., do you re-use existing parts, or replace shims and retention hardware with each brake job?

I was able to reuse everything in 2 changes only putting in new pads. I put a very thin film of high temp grease on shims so they wouldn't stick to pad or piston. Lexus recommends replacing the caliper bolts but I just use a dab of locktite to keep them locked. I didn't even resurface rotors as they weren't scored or warped.

[billydpowell]

I just replaced mine and used pads only, rotors were not turned, they were true, no wobble or pulseing.

reused all old hardware, plus anti squeel..

quite as a mouse and VERY solid brakes.

[eatingupblacktop]

Yeah Depot, you can reuse the shims and I would apply some brake quiet. Here's a previous post I made if you want some other tips:

http://us.lexusownersclub.com/forums/index...st&p=391197

[landar]

EUBT also has a good suggestion in that other post about bleeding out the fluid when compressing the piston rather than sending it

on up the line. I had never thought of that but going to try it when I do the rear brakes this spring after the ice thaws. (Mike...I am envious of your weather right now).

[Depot]

Ok I'll get the brake quiet grease and use it. Does this go on the outside of the shim, or the side that goes against the pad, or both?

It appears I'll only have to get the front rotors turned, but they must have gotten this way before I bought the car, given my pads aren't critically worn.

This is my first disc brake job, I hope it goes well!

[curiousB]

I would only have rotors turned if you have pedal pulsation at slower speed braking or obvious scoring on the face. Otherwise I'd just replace pads. I think dealers insist on resurfacing just to increase the labor content of the repair. It seems more motivated by revenue grab than true need.

[billydpowell]

I would only have rotors turned if you have pedal pulsation at slower speed braking or obvious scoring on the face. Otherwise I'd just replace pads. I think dealers insist on resurfacing just to increase the labor content of the repair. It seems more motivated by revenue grab than true need.

LISTEN TO THIS MAN..... if you have no wobble or pulsation, just pads only.

The anti squeel I used, went on the FACE of the PAD, not the shims, check out what you are doing, ask the auto store, they should know

[Depot]

It's a done deal, and I did NOT turn the rotors. I did crosshatch them inside and out with 80 grit emory cloth though.

Bedded them in (30/30/30) and test frove it on the interstate and have no issues.

Oh, the brake quiet? I didn't use it. I may regret that later, we'll see.

My brake wear light is still on, so I simply cut the wires and tied them together. I don't need an idiot light anyway to tell me when I need brakes PLUS it lied to me, I had another 10k left!

[curiousB]

My brake wear light is still on, so I simply cut the wires and tied them together. I don't need an idiot light anyway to tell me when I need brakes PLUS it lied to me, I had another 10k left!

I agree with you on the wear indicator. Technology solving a problem that really isn't much of a problem. A $70 wire pigtail to tell you your $50 pad is wearing?!?!?! Might want to put a dab of RTV/Silicone over spliced wires so they don't corrode in moist air.

[1990LS400]

A $70 wire pigtail to tell you your $50 pad is wearing?!?!?!

I think you're missing the point. The reason for the brake pad wear sensors is not to protect the brake pads -- it's to protect you. I've known people who don't maintain their cars very well and their first warning of worn out brake pads has been either hearing metal to metal contact when they applied their brakes or wondering why their cars took so long to stop.

Regarding whether or not to turn the rotors ... I have sometimes noticed a very slight pulsing of car brake pedals after brake pads were replaced without turning the rotors. My wife tells me I'm obsessive (hmmm, me?) but I tend to like things to be sort of perfect. Besides, brake pads on the LS400/430 last a long time compared to many other cars -- it's not as if the brake pads have to be changed and rotors turned very often.

I had the front brake pads on my 00 LS changed for the first time at 71,293 miles and about 5 years 8 months from the car's in-service date when the wear sensor triggered a warning message in the dash display. The original rear brake pads will be changed - probably in March - at the 120,000 mile service which will be about 9 years 8 months from the car's in-service date ... I could probably squeeze another 5,000 miles out of the rear pads but I'll them changed for convenience since, as much as I like mechanic Fred, I don't plan to see him again until the 150,000 mile service.

The cost of having Fred remove and turn my rear brake rotors will be about $100 which means that the cost of turning them can be amortized over nearly 10 years -- that's between 2 and 3 cents per day if I calculated correctly -- "peanuts". As I said, I tend to like "Perfect": If I'm going to spend a lot of money on nice cars, I want the best driving experience possible from them and I don't mind spending a few peanuts to get it.

[curiousB]

I think you're missing the point.

We all have our own opinion. Many cars have a $0.015 metal tab on the pad. As the brake pads wear down, this little metal tab that scrapes along the rotor. It's a typically a high-pitched or grinding noise. It does this to indicate to the driver that the brake pads need replacing. To me that achieves the protection you note but does so without unnecessary complication of electronic indicators and wear sensors (which are little more than sacrificial wire loops embedded in plastic). I'm all in favor of technology where it matters. Sometimes though it gets used for frivolous features. I put break wear sensors right up there with aquarium screen savers for PCs.

As for rotor turning you seem to imply its a better solution. I've experienced the opposite. As your rotors get turned they get thinner. That means less thermal mass and more prone to over heating. Over heating leads to warping. Warping means replacing rotors. So I wouldn't fix something that isn't broken.

[eatingupblacktop]

As some say, "Variety is the spice of life"! Others say, "Opinions only matter when they're your own"! Which brings us to what I say ... If you drive like 1990, then his method of servicing his brakes makes sense except I don't think my dealer would accept peanuts. lol As for the sensors, if you are a diy, then you should be aware of not only the condition of your brakes but vitually the whole car. If you're not, then the sensors do function for those who have other priorities and are willing to spend the peanuts for what some would label as a silly expediture.

As for turning rotors ... a slightly warped rotor would definitely benefit from machining. The question is ... for how long? Even a quality disc, if sufficiently overheated, can suffer metal fatigue which cannot be repaired by machining. Such a condition would lead a turned rotor to begin warping again at the first instance of overheating (heavy braking). A rotor that has worn to a high spot (due to defective manufacturing) will also benefit from machining, but only until enough material subsequently wears to reveal the defect again. Personally, if I have a warped rotor, I simply replace. So it could be said, service your brakes according to your own condition.

I've attached a Lexus TSB (parsed from a pdf) for anyone interested in the finer details of greasing your brakes:

[1990LS400]

As some say, "Variety is the spice of life"!

Diplomatically stated, my Canadian cousin.

[landar]

Thanks for posting that TSB, eatingup. That is exactly what my brakes are doing (clicking). I wanted to post but it

seemed rather frivolous(if that is possible with a Lex). I did not associate it with a change in direction but it fits. Will give the grease a try.

BTW, what/where do you subscribe to get the TSB's? Or are you not telling? :whistles:

[Depot]

Thanks for the bulletin eatingupblacktop. By the looks of it no grease gets applied on the shims themselves, as many have recommended.

[RDM]

I'm late on this, but have comments as well. I do brakes on a variety of cars including mine, my parents, friends, and some customers, a total of maybe 30 cars typically during the year, I never put shims back in on any car I do. I just put the raw pads in and that's it. Some cars just squeak from wear or the type of pad, I've found both my parents' Cadillacs constantly make noise if I use full metallic pads, semi metallics make less noise, ceramics are dead quiet. Other cars like other types of pads, but the shims are a useless item IMO. My LS is a '92 currently with the original brake parts but I have a set of 1998 rotors and pads ready to go on when I get time to buy calipers. I've changed the fronts once and used metallic pads, no issues except some dusting, rears are still the ones that were on the car when I bought it for 45k miles ago. I think shims are used by some people for the illusion of a quiet install but I've never seen putting shims back in quiet a noisy caliper. To each his own though, the extra few dollars doesn't hurt if you're a believer of them.

[1990LS400]

BTW, what/where do you subscribe to get the TSB's? Or are you not telling? :whistles:

There are a number of websites where you can view TSB's. Two popular ones are Chilton and ARRC, available through many public libraries. Many libraries allow access from outside the library premises through a library website using a userid and password.

A school in the Toronto area "left its barn door open" and you can get to ARRC (Auto Repair Reference Center) and view TSB's and other information without a library userid and password: http://www.senecac.on.ca/library/resources/ebsco_arrc.html

[eatingupblacktop]

BTW, what/where do you subscribe to get the TSB's? Or are you not telling? whistling1.gif

There are a number of websites where you can view TSB's. Two popular ones are Chilton and ARRC, available through many public libraries. Many libraries allow access from outside the library premises through a library website using a userid and password.

A school in the Toronto area "left its barn door open" and you can get to ARRC (Auto Repair Reference Center) and view TSB's and other information without a library userid and password: http://www.senecac.on.ca/library/resources/ebsco_arrc.html

Very generous of them isn't it! You can also get them from your dealer.

[eatingupblacktop]

Thanks for the bulletin eatingupblacktop. By the looks of it no grease gets applied on the shims themselves, as many have recommended.

Although there is no direction for greasing the shims in this TSB, keep in mind it's addressing a specific prob and doesn't encompass all aspects of replacing brake pads. If you look at pg 3, it shows application to the caliper on the opposite side of the pistons. This could just as well be the shim or the backside of the pad. In his tutorial, LexLS shows how to apply the grease but leaves it up to you whether to apply or not. If you have left out the shims whenever you do your brakes with no probs, as RDM writes, then there would be no reason to change. The choice is yours.

[landar]

There are a number of websites where you can view TSB's. Two popular ones are Chilton and ARRC, available through many public libraries. Many libraries allow access from outside the library premises through a library website using a userid and password.

A school in the Toronto area "left its barn door open" and you can get to ARRC (Auto Repair Reference Center) and view TSB's and other information without a library userid and password: http://www.senecac.on.ca/library/resources/ebsco_arrc.html

And all this time I thought you were "making it up"? ;)

Thanks for the link!