Caliper Grease On Piston?

[Drew2000]

I apply a thin film of Krytox GPL226 grease to the pistons and pins. Krytox is totally inert and the GPL series has a corrosion inhibitor. It makes a big difference in corrosin protection and allowing the pistons to properly retract esp, on motorcycle calipers that are exposed to weather. Krytox is amazing for lots of lube-related applications.

Drew

 

[The Critic]

I would try Permatex Synthetic Caliper Grease. It's green colored and is sold in single-use packets at the counter.

 

[tom slick]

on the pistons?

 

[Carmudgeon]

Originally Posted By: Craig in Canada
If your caliper piston takes grease, there is usually special grease for that purpose.


This is worth reiterating.

Quote:
I can't answer for YOUR piston, but mine are made by ATE, and ATE sells a lubricant in small packets which is to be used when rebuilding the caliper (ie. replacing the seals). This is not part of a typical brake job, only a caliper refresh.


Ate Plastilube is the product you're thinking of. It's available in 35 or 75ml tubes. Any German or other automaker that uses ContiTeves as an OEM probably resells the same stuff under their own label. I know BMW does in small packets.

Lucas/Girling also has their own grease.

 

[moribundman]

Originally Posted By: Carmudgeon
Ate Plastilube is the product you're thinking of. It's available in 35 or 75ml tubes. Any German or other automaker that uses ContiTeves as an OEM probably resells the same stuff under their own label. I know BMW does in small packets.


A comment on "Plastilube:" The product is made by Henkel-Teroson (and otheer manufacturers worldwide) and sold under many labels, including ATE. It is a light brown mineral oil grease with bentonite. It may be used on the pad backing plate and backing plate contact points to prevent brake squeal, but it's not suitable for other brake components. If ATE or Lucas include a pouch of lube expressly to be used with piston seals and/or guide pins, then that is a proper lubricant, but it's not good old universal longlife Plastilube grease.

The last few OEM Audi brake caliper rebuild kits for ATE and Lucas calipers that I bought came with a little pouch made by TRW. The fluid is for soaking the piston seal before installation. I confirmed with Audi that use of the fluid is optional. The piston seal may be installed with just a bit fresh brake fluid applied or with the shown lithium grease G 052 150 A2. The lithium grease is safe on all brake components.

I use these days G 052 150 A2 when installing brake piston seals. I also coat the piston with a very thin layer. I also rub some of that grease on the inside of the brake piston dust boot (sleeve). On the slide pins and guides I use the shown Permatex ceramic lube, which has worked very well for me.

VW/Audi/Porsche/Seat/Skoda G 052 150 A2 Brake Assembly Lube:

 

[Craig in Canada]

Originally Posted By: artificialist
Do you have a Chrysler product?

Most Chrysler products have a phenolic piston, which is not as strong as as steel, and tends to enlarge. When that happens, it usually does not retract into the caliper as it should.

There are replacement piston and seal kits.


No, I have a vehicle of German heritage. The Germans like things like special greases.

On my forums there was a gentleman who disassembled and cleaned everything because he's into maximum maintenance. Everything was squeaky clean (you'll see why this is funny later). His calipers started creaking afterwards. When stationary, working the brake pedal caused creaking from the caliper. Many disassemblies, cleanings, and lubricatings later it was still doing it.

He got a pointer to the ATE caliper assembly grease which goes on the piston where it meets the seal. Despite the fact that he tried other silicone-based or whathaveyou greases on assembly, only the proper ATE grease stopped the caliper from creaking. Go figure.

I find it also worth mentioning.... A lot of people phrase responses with comments about the pistons moving in and out, and proper range of motion. There's not a lot of motion involved, at least in a disc brake system. The pads run at zero clearance - they are not withdrawn into the caliper by the braking system they are simply pushed off to zero clearance by the rotation of the disc - nothing more. These are not like bicycle brakes which sit 1/4" off of the rim when not in use. Further, the steel and pad material isn't very compressible, so they still don't move all that much when going to full braking, but there is lots of pressure. This pressure swells anything flexible, and slightly distorts the caliper etc... which is why your brake pedal is moving. On sports cars there's less of this, and the brake pedal is very hard and firm - modulating brake action is then more an act of varying stationary pressure on the pedal instead of the pedal moving up and down.

Anyways....

 

[V1]

This was some good info. Thanks a lot.

It was a bad caliper after all though. I got a (new) used one from the junk yard and istalled it. Problem fixed.

 

[labman]

Originally Posted By: Kestas
I butter the caliper bore surface with silicone grease. This is a hot spot for corrosion, and I'm not sure the fluid right against the seal gets completely flushed during service. I then butter more silicone under the dust boot. This seals out any moisture, which is a big problem in the rust belt. Silicone is completely compatible and inert with brake fluid and the elastomers.


Right! I doubt how much good fluid flushes do the part of the piston inside the seal. They are totally useless as far as the part outside the seal goes, which is where the pistons rust. I am partial to Sil-Glyde from NAPA.

 

[Kestas]

It's interesting you should quote me, labman. I got the idea from you some three years ago!

 

[doitmyself]

Originally Posted By: labman
Originally Posted By: Kestas
I butter the caliper bore surface with silicone grease. This is a hot spot for corrosion, and I'm not sure the fluid right against the seal gets completely flushed during service. I then butter more silicone under the dust boot. This seals out any moisture, which is a big problem in the rust belt. Silicone is completely compatible and inert with brake fluid and the elastomers.


Right! I doubt how much good fluid flushes do the part of the piston inside the seal. They are totally useless as far as the part outside the seal goes, which is where the pistons rust. I am partial to Sil-Glyde from NAPA.


In what circumstances do you guys rebuild the caliper? Preventative maintenance every xxxx miles? Or, just when you suspect some problem?

The last time I considered a caliper rebuild on an Escort, cost of rebuild components (piston, too) were only $15 dollars cheaper than a complete rebuilt caliper....not worth the trouble in my opinion.

Pictures sure would help. You butter the caliper bore "inside the seal" where fluid would be. Butter the seal and "outside" the seal where the dust boot would press into? Butter means a paper thin layer, correct?

Some of you butter the piston......when the piston gets pushed in, won't the seal scrape that grease off and into a big glob next to the seal?


Finally, labman, is this your first visit back in many months? Aren't you the one who harped at us to not over-look servicing our calipers? Welcome back, I think. Regarding your Sil-Gylde preference, I was surprised to learn it is not really a silicone lube, but consists mostly of propylene glycol and castor oil.

 

[vxcalais]

Permatex ceramic brake parts and the green lube (can be got in the small sachet) are some of the best you can get. (AGS) Sil-Glyde is good as well. Have a look at the Amsoil greases, they will have suitable synthetic ones as well. Some parts need brake fluid as a lube, some a silicon/Synthetic or rubber grease(castor base) grease can be used. NO mineral grease full stop.

 

[vxcalais]

http://www.imperialinc.com/msds0075150.shtml

THis stuff certainly has silicon.

http://www.agscompany.com/products.php?line=5&category=17&subcat=97&product=212

Above is the one i use, top stuff. Certainly uses silicon. It better be for what i pay for such s small tube. Up to 13% Silica. The base has to be glycol based (Synth) as this is what makes it compatible with the brake system, brake fluid being glycol based. As the workshop manuals state, from these MSDS you can just use brake fluid, but wont last as long as the grease obviously.

 

[doitmyself]

Quote:
THis stuff certainly has silicon.


Where??? Your newest MSDS must be the new reporting style where ingredients can be left off OR, Silglyde has changed their formula drastically (not likely). Don't confuse silica (a filler) with silicon (polydimethysiloxane).


Here is a slightly older MSDS where it list all the primary ingredients. Note that silicon is less than 5% while propylene glycol and castor oil make up the greatest components:

http://www.worldpac.com/msds/pdfs/WP_092.pdf

 

[Craig in Canada]

...and I wish that 50% or more of the general population would stop confusing silicone and silicon.

 

[doitmyself]

Complaint noted! Thank you. Funny, I spelled it right in my first post, then sheepishly followed vx in the next round. BAAAA...

Lets see now. It's Silicone, with an e and Gary Allen, also with an e (not "a"). Should be able to stay on track now.

 

[mechtech2]

Not many of us are in the business of rebuilding calipers for sale - maybe years later.
Brake fluid is all we should therefore use when rebuilding them.

 

[moribundman]

Originally Posted By: labman
Right! I doubt how much good fluid flushes do the part of the piston inside the seal. They are totally useless as far as the part outside the seal goes, which is where the pistons rust.


"Where the piston rusts."

Here's the 11 year old piston of my left front brake. While aluminum surely can corrode, the only spot where I see some staining is away from the groove in the piston that holds the piston boot. There's not rust or corrosion on any part of the alu piston that is protected by the boot. Then again, I do flush the brake fluid every two years (as required by the car maker) and I do replace all piston seals and boots every 4 years.

So, you guys got rusty iron or steel pistons?

 

[Kestas]

Rub it in, Mori.

Many of us drive in the Rust Belt and have steel or cast iron components, which makes fertile ground for corrosion.

 

[moribundman]

*rubs it in*

I live 300 yards from the ocean with a sea breeze exposing everything to salty air -- not to mention the destructive powers of wind, sand, and fog.

 

[Kestas]

Okay, I'll take it back. I've actually seen the cars that live near the ocean in San Francsisco, and personally experienced what happens on the Florida coast.