Brakes: Caliper grease on brake shoe pushrods?

[bsrosell]

Hi, in a previous post regarding brakes, " no lubricants " on rubber was stressed. But wouldn't the typical synthetic caliper grease used for modern disc brakes be well placed on each operating pushrod (pin coming out of wheel cylinders on each side)? Better than using brake fluid, and it IS designed for constant contact with the rubber bellows on your disc brake calipers... what I'm using on wear pads and ends of shoe contact points...... Any reason NOT too? ( different rubbers, for example?) Need something there, constantly moving in and out when applying the brakes. Thanks!

[StudeRich]

There is no need for any Lube on the shoe contact end of the push Pins, but the Ball end that contacts the Wheel Cylinder Piston gets High Temp. Lubriplate or other high temp grease.

If you are talking about Lubing the "PISTONS" they will be indirectly in contact with the Brake Fluid, and need only Brake Fluid or Hydraulic Cylinder Lube, I would not use anything for Disc. Brakes on a Drum Brake System anywhere, except maybe Wheel Brg. Grease and Brake Fluid.

[bsrosell]

Thanks Rich; no, I'm talking about the pushpins where they are in contact with the rubber cylinder boots. What do you use there? No brake fluid there ( unless there is a leak!). Or unless I deliberately lube the pins with DOT5 , INSTEAD of the brake caliper lube at assembly; thus my question. Just seems the heavier ( black synthetic) caliper lube would stay in place longer at the rubber seal and not weep all over. I guess I don't understand the issue since it is isolated from the rest of the brake system & fluid by the piston. But, shop manual doesn't specify lube for anything except the shoe contact points, so maybe nothing is needed there, and one less area to collect brake dust!? :-)

[Dwain G.]

Most caliper grease is intended to lubricate metal-to-metal contact parts only.
The area you are concerned about usually would not get lubed because the pin doesn't slide back and forth through the rubber boot. Instead, the boot expands and contracts with the pin.
Whatever you do buy, read the label for 'plastic and rubber compatible' like Sil-Glyde Brake Lubricant or similar.

[StudeRich]

Barry, did anyone ever tell you that you tend to overthink things? Those "Pins" will be fine, just put em together, it's NOT a Rolex!

[bsrosell]

That's the problem, my other hobby IS pocketwatch repair. 🤓