What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Brake caliper pin lubricant

Captain_John

Well Known Member
So, I was wondering what you use on your calipers to ensure good movement of the caliper on the pins.

My A&P IA friend says anti-seize. That sounds reasonable.

I have read the Cleveland Technicians guide and there is NO MENTION of lubricating these parts at all.

What's your take?

:rolleyes: CJ
 
Lube

I just installed a set of matcos on a -10, and again nothing in the install docs mention it. I?ll stay tuned. But a little anti seize couldn?t hurt.
 
So, I was wondering what you use on your calipers to ensure good movement of the caliper on the pins.

My A&P IA friend says anti-seize. That sounds reasonable.

I have read the Cleveland Technicians guide and there is NO MENTION of lubricating these parts at all.

What's your take?

:rolleyes: CJ

dry moly lube

But general service history that I've seen seems to indicate it isn't really necessary.
 
Last edited:
So, I was wondering what you use on your calipers to ensure good movement of the caliper on the pins.

My A&P IA friend says anti-seize. That sounds reasonable.

I have read the Cleveland Technicians guide and there is NO MENTION of lubricating these parts at all.

What's your take?

:rolleyes: CJ

For the past 20+ years and over 3,300 operating hours, I have used the brake manufacturers recommended lubrication. Nothing. I just clean them off and put them together.

Any liquid, paste, or grease will just collect brake dust and prevent movement.
 
My Take is I use lube.
Like Scott said, Dry Molly Lube...
or one of many "brake caliper greases" on the market at the auto parts store or Amazon. It is very similar to anti-seize. My thoughts are if you don't fly much or in nice enviroments and service (clean)your brakes annually, you might not need it. But if I have the assemblies off, which I do every year, I clean and re-lube very sparingly. Too much might attract unwanted debri to collect. You will not need much, if you buy a small tub, 1/2 pt. maybe, it will last two lifetimes. I have a small tub and I use a acid brush to apply it. After all, they do make the product, why not use it?
 
I asked Matco's service rep and he said to just keep them clean and dry. In my experience, any form of lube is generally bad in that it attracts and holds dirt and grit leading to wear and sticking slider pins. I use silicone spray (dripped on, not sprayed) or dry graphite on my various aircraft and car slider pins.
 
Dry lubricant, if any, period. Unlike automotive pins which are weatherproofed in accordion style sleeves, ours are exposed and will collect dust and dirt like a magnet!
 
moly powder or nothing

Polish them [and the inside bore] lightly and leave them -- or apply powdered moly lightly with a cloth [you don't leave much behind, or need much]. You are generating grit with your brake pad right there -- ANY liquid/ carrier will attract and hold the grit, which turns your parts into a grinding machine.
The moly will impregnate the surface pores, so you'll build up a lubricating surface - but the real key is keeping them clean and smooth.
 
Dry graphite

On the farm equipment, we use the dry lube so dirt does not collect as it would on greased parts. That product was also spec?d by Beech for the slide tubes on the landing gear in the 30s - I did not know that stuff was around that long.

Farm stores sell it in a spray too, with what smells like an acetone carrier that flashes off quickly.

Messy stuff tho!
 
I have always used a high temp anti seizing compound. It keeps moisture off of the metal parts. If you were to get the breaks wet - either by flying in the rain, or landing on a dew covered grass runway. The parts could easily rust and begin to bind with a few weeks of down time.
There is no right or wrong answer, you need to decide how you feel about it.
If you try anti seize and the parts wear out because it "attracted" dirt then I will personally buy you a new set of parts. Dirt is going to get there with or without the anti seize. - As Mike Bush says: corrosion, not wear, is the enemy of airplanes.
 
Well Gents, this was my decision:

I took in all this information and what Cleveland says and followed the advice of my A&P IA friend.

As mentioned in this thread, I polished the bore and pins. I checked the pins for damage (like being bent or out of line) and there was none.

I then put a very light coating of Permatex Anti-seize on the pins and reassembled them. So far I have about ten hours on them and they seem to be sliding just fine.

What called my attention to them in the first place was an event upon rollout when clearing the runway, one caliper was binding badly. It was enough to make me think that I had a flat tire. The jury is still out as to why that actually happened. Prior to this, I always assembled them dry as recommended by Cleveland. I figured that I would try the Anti-seize for another data point.

Thanks for all your input. Looks like you can't go wrong whichever way you go?

:) CJ
 
Well Gents, this was my decision:

SNIP
What called my attention to them in the first place was an event upon rollout when clearing the runway, one caliper was binding badly. It was enough to make me think that I had a flat tire. The jury is still out as to why that actually happened. SNIP
:) CJ

Be careful here. I had the exact same problem and in short order it totally trashed a tire and the brake pads on that side.
The root problem was a rolled O ring in the brake caliper. I now carry couple of spare O rings and brake pads in the plane.

Carl
 
Brake pin lubricant

My first hanger land Lord was an old a&p that took me under his wing. He told me to use boelube. Aircraft spruce sells it. It's like a big stick of white wax. BOELUBE? BL70200-13 SOLIDS LUBRICANT - 1.6 OZ PUSH TUBE
476 hours on RY and no problems. Yrmv
 
Carl,

Thanks for the tip. While the caliper was out I removed the puck and installed new O rings. The old one was perfect.

Thanks!

;) CJ
 
Well Gents, this was my decision:

I took in all this information and what Cleveland says and followed the advice of my A&P IA friend.

As mentioned in this thread, I polished the bore and pins. I checked the pins for damage (like being bent or out of line) and there was none.

I then put a very light coating of Permatex Anti-seize on the pins and reassembled them. So far I have about ten hours on them and they seem to be sliding just fine.

Thanks for all your input. Looks like you can't go wrong whichever way you go?

:) CJ

The pins don't slide in and out... The first time you set the brakes after replacing the pads, the pins move in so the pads contact the disc. After that first set, the pins only move a few thousands during brake application and release. But, as the pads wear, the pins must be able to move in to allow the pads to contact the disc. The pins move in less than .10 during the life of the pads.

Do your own test, If your pads are wearing down even, then you are doing what the pads like.

The pins won't bend, the casting will crack where the pin is bolted.
 
Yeah, I know that the pins don't move.

By, "they seem to slide", I was referring to the caliper/ pad assembly.

Sorry if I wasn't clear about that.

:cool: CJ
 
My first hanger land Lord was an old a&p that took me under his wing. He told me to use boelube. Aircraft spruce sells it. It's like a big stick of white wax. BOELUBE? BL70200-13 SOLIDS LUBRICANT - 1.6 OZ PUSH TUBE
476 hours on RY and no problems. Yrmv

This was my choice also.

I might try it on another occasion!

Thanks for the reassurance!

:D CJ
 
Yeah, I know that the pins don't move.

By, "they seem to slide", I was referring to the caliper/ pad assembly.

Sorry if I wasn't clear about that.

:cool: CJ

That's the part that only moves less than .10" during the life of the pad....

Sorry I wasn't clear on this.
 
Judging by the witness marks on the pins, and by simply grabbing the caliper, there is a lot more movement than you think. You can't just go by pad wear. There is a reason these pins have a lot of clearance. They don't just move in and out, they vibrate, chatter, and oscillate fore and aft, as the center piston brings the pads home and they find there place on the disk.
This isn't a precision system for a reason. Things go from super cool to super friction induced heat quickly. It gets hot down there fast, and cools fast, so you need a lot of pin clearance to deal with it.

As far as lubrication, I follow the manufacturers recommendation.
 
Back
Top