Speculate on this (brake replacement)...

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deeter16317

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Our 09 Forester FXT needed brakes at 36k (fronts less than 25%, rears less than 10%), the wife drives about 40 miles of stop-n-go three days a week.

So I went to my local parts house and got their best brake pads (front/rear) which were Raybestos Ceramic, some brake clean, some pad anti-squeal, and new brake fluid (DOT4). I started in the front, bleeding the old fluid (DOT3) as I went, lubricating things with neverseize (I had bad experiences with silicone lubricants, never had an issue with neverseize), etc. Nothing was out of place, disassembly was a snap and reassembly was just as easy. There was no visible air bled from the calipers (bled with vacuum brake bleeder), and the bleeders indicated signs of water in the fluid (rusted tips); however, the fluid itself looked perfectly clean/clear.

Here's the neat part...the brakes are grabby (figure that's the new/different pads), but the pedal is a LOT firmer (like it was when new). I cannot imagine that changing the fluid caused the pedal to firm up (one fluid shouldn't compress more than another)...it was enough of a change that even my wife noticed! What caused the pedal to get noticeably firmer?

FWIW, we've owned this FXT since new...it had 4 miles on it when we took possession. And I want to remember Subaru wants brake fluid flushed at 30k?
 
Obviously the fluid had been contaminated if the pedal feel is that much better. I would keep an eye on it and perhaps flush the fluids more often -- the system could have a very small leak or could just be poorly designed and not be very airtight.
 
I replaced my fluid at around the same mileage and noticed the same. I'm still on the OEM rotors and pads at 46k, btw!
 
Originally Posted By: Quest
Let's hope that you are not using Neverseize on rubber boot/guide-pin section...

Q.


+1
 
Replacing the fluid probably got rid of some trapped gas in the calipers. I think brake systems should be bled once a year.
 
Originally Posted By: dparm
Obviously the fluid had been contaminated if the pedal feel is that much better. I would keep an eye on it and perhaps flush the fluids more often -- the system could have a very small leak or could just be poorly designed and not be very airtight.



If it had been contaminated, why did it still appear new? There was little difference in appearance between new fluid and old. I remember fluid darkened with water absorption?
 
Originally Posted By: Quest
Let's hope that you are not using Neverseize on rubber boot/guide-pin section...

Q.



Yes, and on all three of my current cars (and EVERY car/truck I have owned for the past 20 years)...it will outlast silicone by years. I have never had a single issue using it on ANY of my vehicles...I have had issues using silicone where it dried out causing pins/slides to stick.

Two current examples:

I neversieized my truck's brake contact points and slide pins at 40k and proceeded to get 180k on the OE brake pads...pulled those apart, replaced pads and reassembled, sitting at 270k on those (raybestos). I have not had to touch them.

I neverseized my Outback's brake contact points and slides at 54k when we bought it, replaced the brakes just last spring at 140k...same thing, pulled it apart, installed new pads, reassembled. It sits with 158k...it has sticky/stiff caliper pistons, but that's not from neverseize.

And all of these are in the rust belt of PA...I don't care what you been "told", I've used it and it works well for me.
 
Originally Posted By: A_Harman
Replacing the fluid probably got rid of some trapped gas in the calipers. I think brake systems should be bled once a year.



I could see air accumulating over time as things in the reservoir are agitated and entrained air was sucked into the system. I did look to see if any air escaped (none that I noted, but that doesn't mean anything), and I did invert the caliper to see if anything was settled in the bottom.
 
The firmness has a lot more to do with the lubricating of the brake parts if you ask me.
I always now use Sil Glyde on my slide pins and the brake feel is like new when done properly. You do not have to bleed once a year or even that often.. When I do brakes, unless there is a part being replaced, there is no need to touch the fluid unless its really old.
 
I remember when I owned a older Dodge truck 70s/80s that would shoot a stream of brake fluid out of the reservoir if the top wasn't installed (or at least without a significant amount of fluid in the reservoir) and the brake pedal depressed.

That's where I was thinking you could get air entrained in the fluid, as it was sprayed around inside the reservoir; and those small air bubbles could then be drawn into the pressurized part of the system with further applications of the brakes. Even the vibrations of driving could entrain air?

Not sure if these newer master cylinders operate similarly.

The brake components were surprisingly clean considering this was the first time they had been apart. Everything floated free, but I'm sure lubricant would make things better. I wish more manufacturers would powder coat their brake parts to prevent rust...
 
Anti seize is NOT lubricant for moving parts.
A poor choice for brake parts.
Use what is designed to lube brakes, folks. Or at least a good grease.

The brake pad's composition is different from before. the friction ratings [like EE,EF, FF, etc] are most likely different.
This explains the grab.
 
Originally Posted By: mechtech2
Anti seize is NOT lubricant for moving parts.
A poor choice for brake parts.
Use what is designed to lube brakes, folks. Or at least a good grease.

The brake pad's composition is different from before. the friction ratings [like EE,EF, FF, etc] are most likely different.
This explains the grab.



I completely disagree. But I've only been doing this for about 20 years and probably more than 1.5 million miles combined.

Keep in mind, this is not a part that "moves" like a bearing...it is a mainly stationary part, and only creeps as the pads wear and has minimal movement (sliding) during braking (as in thousandths of an inch). This is a perfect place to use a neverseize. My parts don't wear out (that includes the rubber bushings), nothing binds, and everything comes apart nicely when you do a brake job.

I'm not going to further argue to prove that my way works just fine...telling people it doesn't work is unfounded.

Have a nice day.
 
Sometimes brake feel changes when replacement pads don't 100% match the OE pads.

I remember once the brakes felt softer when I replaced the OE front pads of a 2002 Toyota Solara with Napa Ceramix pads that were supposed to totally duplicate the OE feeling.

I flushed the fluid with Valvoline DOT4 1 year before that job was done, so that was a constant, not a variable.

Brake fluids do vary in viscosity, so pedal feel can change with a fluid change. Whenever I would replace General Motors OEM DOT3 with Valvoline or Pennzoil DOT4, the pedal would get softer even though no air got introduced into the system. Perhaps Subaru DOT3 is less viscous than Valvoline DOT4. Some of the newer vehicles are specifying a less viscous fluid, stating that it helps the ABS hydraulics work more quickly and more effectively.
 
Brake pads are like ice cream, the number of flavors seems unlimited!

Changing pads can really change how the brakes feel, and how they work. Not something to be too casual about.

And I do NOT agree with any grease on my brakes. When those calipers heat up and that grease flows like water... think about it.

Caliper grease is a different animal, made for this application.
 
I have 2007 Outback Sport. It seems to get a little air in it over time. Now when I rotate the tires I gravity bleed the system. I have had a lot of cars and this is the only one that has ever done this.
If your fluid was dark that means heat dirtying-up the fluid. Moisture would cause the fluid to look white.
 
Changing brake fluid has always resulted in better pedal feel.

Brake fluid is hygroscopic it absorbs moisture as soon as the seal on the container is broken. Ideally it should be flushed every other year.
 
Originally Posted By: deeter16317
Originally Posted By: mechtech2
Anti seize is NOT lubricant for moving parts.
A poor choice for brake parts.
Use what is designed to lube brakes, folks. Or at least a good grease.

The brake pad's composition is different from before. the friction ratings [like EE,EF, FF, etc] are most likely different.
This explains the grab.



I completely disagree. But I've only been doing this for about 20 years and probably more than 1.5 million miles combined.

Keep in mind, this is not a part that "moves" like a bearing...it is a mainly stationary part, and only creeps as the pads wear and has minimal movement (sliding) during braking (as in thousandths of an inch). This is a perfect place to use a neverseize. My parts don't wear out (that includes the rubber bushings), nothing binds, and everything comes apart nicely when you do a brake job.

I'm not going to further argue to prove that my way works just fine...telling people it doesn't work is unfounded.

Have a nice day.





I have many shop mechanic friends who claim the same thing(great success) when using Never*Seez and have only used N*S over the last 30-40 years on their brakes. Most of these guys are/were machine shop mechanics who also work on their own trucks and family vehicles.

But too, many garage mechanics/ASE Cert Techs that I know also use regular brake lube such as Permatex or other brands successfully as well.
Myself, I like Permatex "Black" lube compared to the "Green" lube as the "Black" certainly seem to last much longer here in the salt belt of Upstate NY. The Permatex "Black" also seem to keep out moisture/salt better over a longer period of time. And I have read here @BITOG the the Permatex "Purple" lube is even better but, IDK as I have never seen it on the store shelves.
 
Simply, AS is not a lubricant, and they say so.
No mfr ever uses it on their brakes.

Because of these two facts , what does this tell a thinking person?

I don't care if you use bacon grease, but it is not right to tell others to do so.
 
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