Are the caliper bolts truly not reusable? I'm about to replace both front wheel bearings / hubs on my 05, which means I have to take the calipers off. If they aren't reusable, why not?

Thanks,

Jim

 

they are reusable. Lexus may not consider them reusable because corrosion can cause problems and the last thing a lexus owner wants is to have to have the car worked on twice for one problem.

 

They may be stretch bolts. The bolts stretch when they are torqued to spec. The stretching keeps the bolts tight through their service life of extreme heating and cooling. You may get away with using them a second time but each time they're torqued they neck down a bit and may break when torqued up or later in service.

 

Just a parts department revenue grab. The replacement bolts come with threadlocker on threads. I've reused my old bolts with blue locktite and no problems.

 

Technically they are NOT reusable.

As per Lexus (states in the service manual), the bolts are not reusable and need to be replaced when removed.

Can you reuse the bolts regardless without any problems? Maybe but Lexus requires you do not reuse them for a reason. If any damages should occur for the reason Lexus states that the bolts are non-reusable, are you ready to spend the money to repair the damages? Small price to pay for piece of mind.

Incase you're wondering...Yes, I have replaced when with new bolts when I removed my calipers.

 

I highly doubt that a high tensile steel bolt that's being put into Aluminium alloy is going to be getting torqued into it's elastic region. It'll strip the threads out of the mount long before that happens.
I reckon it's more to do with corrosion than anything else.

I reused the bolts on my own car when I did a disc replacement not long after buying it,and it's not worrying me in the slightest. If you're unsure about whether it's ok for you to do the same,buy new bolts.


Justin...

 

Has anyone had a Lexus dealer do a brake job on their car, including the rotors? I'd be curious to know if the repair invoice included new caliper bolts...

I ordered new bolts last night before anyone had a chance to respond here... I won't decide whether or not I'll put them on until I get a chance to look at the condition of the old ones when I take them out. The thread lock is a good idea if I reuse the originals.

Thanks

 

i have never heard of this.... Does this pertain to any other Lexus vehicles?

 

Yes. It is included.

 

I may be wrong but I believe all the ones with the factory big brakes pretain.

 

Stretch bolts are an engineering reality. I wouldn't want to try to reuse any stretch bolt that has been torqued to the design point.

 

I think all hi torque bolts are "stretch bolts" On high performance engines some builders measure the amount of stretch instead of using torque numbers.

 

How much money are we talking here?

 

From Sewell, for all four wheels with the CL discount, $35.60 or $4.45 per bolt... I happen to be paying an additional $22.67 for two day shipping so I can get them for this weekend, so its costing me $58.27 for the eight bolts... Since I'm doing both front wheel bearings, I'm going to mic out the front rotors and make sure they're in spec. If not, I'll replace them at the same time and throw new pads on...

I found this article that explains the concept of a stretch bolt very well... If the bolts bolted in from the side, like on the 1st gen LS400, it would be the shear strength of the bolts that would be the predominant factor. Since these bolts bolt in from the back of the caliper, every time you apply the brakes, the bolts have tension being put on them length-wise. Now that I understand how they're being utilized, I'll be installing the new ones this weekend when I reassemble.

http://www.gomog.com/allmorgan/stretchbolts.html

 

JimsGX - Thanks for the great informative post.

I called my local Lexus dealer parts guy when I was researching doing my own brakes. He said the Lexus dealer techs always put in new caliper bolts on every LS brake job because factory service manual calls for replacement as the caliper bolts are designed to be one use only.

But he said most independent brake shops that do LS brake jobs do not put in new bolts and he had never heard of any problems.

Given the relatively low cost of the new bolts, I view it as cheap insurance so I will put new bolts in if I have to machine or replace my rotors. Brakes are serious business...having them fail at an inopportune moment can ruin your whole day.