Disc Brake Caliper Slide Pin Grease(Lube)? Gen2

Yeah Honda's better in that regard, excerpts from older PIlot Shop Manual, attached:

 

Right, the service manual doesn't really give the numbers or the names, but the descriptions.

The numbers are given in various TSBs and clarifying docs.

The Toyota specs people did, I presume.

 

Again, I've got a tube of something, and a tub of something, that I've used for decades, on various makes of cars, for the caliper pins and pad/shim/caliper interfaces respectively. They'll likely outlive me, and haven't caused problems or exhibited incompatibility yet. Both products are cheap and readily available in North America.

 

Nothing wrong with any of that, as long as people who come to PriusChat to find out what the manufacturer recommendations are do in fact find out what the manufacturer recommendations are.

 

Proprietary information is not useful for consumers trying to decide which product to buy.

While shopping for tires recently I was unable to find rolling resistance numbers from manufacturers for any of the tires I was considering. Presumably they have information on that, but they don't share it. In this regard citizens of the EU are in a much better place than those of the us in the US because there is a mandatory tire testing program there, and a web site where one can look up values. (As it turned out, the General Altimax R45's I ended up purchasing seem to give pretty much the same mpg as the Ecopia EP422s they replaced. That was a relief - and mostly luck. They could easily have been much worse and I had no way of knowing that.)

 

Sure, but then I don't think "let me second-guess all the informed choices that were made by the people who designed and built this machine" is the kind of "decide which product to buy" that most consumers are engaging in. Seems like it might be hubris in all but a very small and unusual subset of consumers.

 

That’d be for me, if the quest was availability, price and “I have it on hand”.

 

Extraordinary claims require extraordinary evidence. Not by us, by Toyota. My hypothesis is that that Toyota product is "sufficient but not necessary" for use on glide pins. Toyota is, as far as I know, the only manufacturer that requires that particular type of grease on the slide pins. In discussions of why this particular type of grease, the only functional reason proposed, at the slide pins now, not the piston, is that Toyota might use a special type of rubber boot which is somehow damaged by silicone type greases. I have yet to see a report of that though. Which would be irrelevant in any case if the brakes no longer had Toyota's rubber on them, which is not unlikely if brake work was ever done at an independent shop.

Here is a site which in part discusses what lithium soap does in a grease (spoiler, it is a thickener):

High-Temperature Grease Guide | Machinery Lubrication

That link also says:

We can rule out the lower end of that range because it is below observed operating temperatures on brakes. Who knows what possible other tweaks the Toyota product might have to push the temperature range up a bit. The high end of that range is very similar to many commonly used slide pin greases, which do provide temperature ranges in their specifications:

https://multimedia.3m.com/mws/media/889069O/3m-tm-silicone-paste-clear-08946-8-oz.pdf
Case Study - High-Temperature Lubricants for Brake Caliper Pins
MOLYKOTE® G-3407 Caliper Pin Grease
Sil-Glyde Silicone Brake Lubricant– AGS Company Automotive Solutions

Rheosil 500F is particularly interesting - it is a product which is both a silicone grease and contains lithium soap:

https://www.nyelubricants.com/stuff/contentmgr/files/1/701918d90e7061e58a0cf5e881b01552/en/specialty_lubricants_for_braking_components_10_07_24.pdf

Do we actually know that the Toyota product does not contain dimethyl silicone?

https://bobistheoilguy.com/forums/threads/my-study-of-compounds-greases-and-pastes-for-lubricating-brakes-on-japanese-automobiles.329794/

says (emphasis added)

 

Nah, by us. Toyota designs and builds a thing and publishes how to take care of it, after they've made thousands of individual decisions, what grease here, what alloy there, what elastomer over there. Happens every day, nothing extraordinary about it.

Nobody's forced to follow their recommendation. A person who'd rather do something else doesn't need to give any reason at all, or can give "availability, price, and I have it on hand" like Mendel, or "I'm evaluating their engineering team's conclusions without knowing their rationale, they should have explained it to me" if that sounds better.

I depart from manufacturer recommendations often enough myself, but if I'm being honest my reason is usually more like Mendel's. And sometimes I'll post about what I did instead, but if I do I'll state clearly it was different from the recommendation, and still at least link to what the recommendation is. A person reading my post deserves not to be misled.