Anti Seize in Brake parts (1 Viewer)

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Dec 20, 2007
Orcas Island in NW Washington State
A couple months ago I replaced all my wheel cyls with sor aftermarket parts. I'm well aware of the problems with frozen pistons and adjusters in these damp climates, so based upon some of your experience, I removed the rubber boots and the heavy steel 'pistons', and coated them and the adjuster threads with anti seize. I know the rubber brake cups will be contacting this stuff, and I would feel ok about that except for the fact I recently remembered that I had thinned the old anti seize with a couple good shots of wd 40. It seems I've always heard that petroleum based oils shouldnt be used with brake stuff, just mineral oils. Have I created a problem here? I don't want to take it all apart, but will. Maybe the anti seize is petroleum based anyways? ....Truck is a couple months away from being on the road. Any thoughts?
Hi Gary,

The adjusters definitely need anti-seize and lots of it.

The pistons? I've never done that. If you are worried that the rubber seals might be damaged by the anti-seize, I'd contact the manufacturer of the anti-seize (and WD40, perhaps) and ask them. They should have a pretty good idea what affect their product would have on various materials. I pose these questions to manufacturers frequently during work and they are usually pretty good about getting me info.

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... If you are worried that the rubber seals might be damaged by the anti-seize, I'd contact the manufacturer of the anti-seize (and WD40, perhaps) and ask them....

:hmm:i can just imagine their response! Hmmm, brake parts...liability=lawsuit. So I'll just tell this guy the CYA answer which is NO because we don't want to get sued.

I personally wouldn't put anything on the pistons other than a light coating of brake fluid. The rubber boots are what are supposed to keep the crud out. I agree on a liberal coating of anti-seize on the threads of the adjusters. Or one could go with discs and never have to muck with any of this ever again.
The adjusters yes. The pistons, I would have left them be you can and probably contaminated your fluid, and the WD40 will swell rubber parts over time..

My thoughts I would pull them and clean it off the pistons, and wash the boots in some mild soapy water (Dish Soap) to get the WD40 off as soon as possible.. and then make sure you bleed out enough to make sure you dont have any Anti-Seize in the fluid..
I'm with everyone else. Antiseize EXTERNAL to the brake system ONLY. I personally would not put anything in the brake system besides brake fluid. I use antiseize on the adjusters, where the shoes contact the backing plate and on the pins that hold the front pads.
Petroleum based oil=mineral oil=grease used as base in antiseeze.

For people who Cruise in a constantly wet/salty/humid environment, putting AS on everything is acceptable. A new cylinder installed dry will last a few years in ohio before the pistons seize w/ rust, or else start to leak from rust scratching the bore, then wearing the cups.

The same stuff treated appropriately w/ AS will go several years longer before failing.

Yes, grease will theoretically cause the brake rubber components to swell/soften/spontaneously combust/etc. However, it has been determined empirically that the risk of AS induced brake failure is dramatically less than the risk of H2O induced brake failure.
Not much to add here without just saying "me too".
But, I've found the most important place to use the anti-seize, along with the threads of the adjusters, of course, is the outside of the adjuster where it sits in the brake cylinder...
Let's just say I WAS to disassemble them and clean them up.... (no brake fluid in the system yet) is there some kind of other grease that would address the frozen piston issue, and yet not attract moisture the way brake fluid would? Maybe something like vaseline. oh wait, that's petroleum jelly, but you get what I mean.... Lard?:) Seems like when I took them apart, there was some kind of grease on them.
So, pighead, you are saying on the outside of the adjuster, and that's what I'm calling the piston. It has internal threads for the adjuster,and the rubber brake cup contacts it. Do many people use anti seize there with lasting results? Wish I hadn't addes the wd.40 to the chemical equation.... :crybaby:
I've had really good luck with Boeshield, Gary. I use it on any exposed, unpainted/treated steel. It works really well at preventing rust in this damp environment that we live in. It is just a wax, with a solvent to make it sprayable. Spray it on, wipe it off. Once dry, it will have no affect on the rubber seals. I'd give that a try.

Hell, I'll throw you another curve ball. I not only added copper based anti-seize to the pistons and cylinder walls, (outside the inner seal area) I powder coated the pistons as well! Sure the powder coat will eventually wear off but it will provide that much more added rust protection before it does.

You will NOT contaminate the brake fluid doing either of these. The piston cups seal the cylinders quite well from any thing on the other side. If they didn't the first push of the pedal would squirt brake fluid everywhere.

You want to be totally anal? Have your cylinders bored out and a brass or stainless liner of the proper size pressed in. Then have the pistons yellow zinc plated. There are several places that will do this procedure.
Ohhh....So we're not talking about A/S on the PISTON piston, we're talking about A/S only on the adjuster piston (inside & out)? That's better. And the rubber brake cup is really the rubber brake cap? No problem. The rubber brake cups are the rubber rings around the PISTON piston. I think.
I religiously use the A/S all around in and out of the adjuster piston. Never a problem with that. Don't worry about a little tiny bit of the WD40 in there, but don't do it again.

So, pighead, you are saying on the outside of the adjuster, and that's what I'm calling the piston. It has internal threads for the adjuster,and the rubber brake cup contacts it. Do many people use anti seize there with lasting results? Wish I hadn't addes the wd.40 to the chemical equation.... :crybaby:
I was thinking 24k gold sleeves with kryptonite pistons, but the hard piston would wear out the bore, and at that point I might as well have just paid a little more and bought oem cyls from toyota... :lol:
And thanks for all the info. Maybe 'll call anti seize and see if its petro based just for yucks. It works fine in this area, I am learning.
OEM are made out of RED kryptonite...
Permatex says not the best to use with brake rubber, as it has petroleum distillates. I guess the wd 40 won't change that..... But what's the very first use listed on the 8 oz container.. and I quote: "Brake Lube Assembly and Anchor pins" hmmmmm wtf? He says use 'Ultra Disc Brake Caliper Lube, Hi Temp'. It's their silicone based product designed for brake pistons. Its on the back side of the cups, and I think if it's been working for you guys I wont change it, unless I really get bored. But next time I'll use the silicone stuff. He also said the anti seize has very little lubricity and was made for use in non-moving parts. Well, now I can decide for myself, armed with some new knowledge.
I'll go with the silicone based grease being the best to use. I use that stuff when working on my Xterra and Pathfinder disc brakes. Never occured to me to try it on the drum brake pistons. :doh:

I still have the rear brakes exposed so I think i will try that on them and the leave the copper based anti-seize on the fronts. Be a good long term comparision, though it will be another year before !Oy's back on the road... :D

Thanks for the new knowledge! ;)
OK, so I've been thinking this over and remembering the two times when I had a complete brake failure with a single master cylinder system... (oh, what a feeling!!!)ok, and the time my son rolled the fj 40 on his way to work on a steep windy road, when the brake pedal went straight to the floor as he was doing the Mario Andretti thing and braking hard going into the curve. So this morning I decided to take the day off and pull the fj45 into the sun and disassemble all 8 wheel cylinders and clean them of anti seize, and re-lubricate the pistons with synthetic grease made for pistons in disc brakes. I asked my napa store guy first if anti seize was ok , and he said if it's in contact with the rubber cups, which it is.... it shouldn't be. He said clean up with brakleen. Petroleum distilates in contact with brake rubber isn't good. I also read a technical article online but don't know how to link it. Anyways, I've done the rears so far, and now I'm off to do the fronts. Takes me about 40 minutes per corner for this peace of mind.
Probably best. And, practice make perfect. I'll bet you're getting pretty fast at disassembly/reassembly. :D
OK. I think I hear a lot of people here saying it is OK to use petroleum-based anti-seize (and/or penetrating oil) on brake adjusters so long as you keep it away from the seals/cups (that stop the brake fluid leaking out). But I beg to disagree with this view.

I wouldn't use penetrating oils (like WD40 or CRC) or anti-seize greases (like copper-grease) or any other petroleum-based product ANYWHERE in the space inside my brake drum (between the drum and backing plate).

I believe heat (from braking-continuosly down long gradients on hot days for example) coupled with occasional water sloshing around (from river crossings etc) would cause the oily residue to migrate to where it will do damage (the piston seals and their protecting rubber boots).

I don't drive in salt water and we don't have salted roads here - But if corrosion was an issue for me on the adjusters (which it isn't) - I would use high-temp silicone grease there.

Just my 2c worth.

(So I think your remedial action is wise Pops.)


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