Help me track down my braking problem :(

[WingsofWar]

Originally Posted by #87

The calipers in the rear were Honda replacement parts. The caliper appear to function properly: slide pins lubricated and slide easily, hand brake functions properly, piston turns back in with minimal effort.

The caliper I bought today was from autozone and looks the same as the one I took off (same markings,, numbers on it).

I originally had brake problems because I never changed the fluid. When I replaced all the brake parts I bleed the whole system and put in ATE Super Blue fluid. I have bleed the system 2 times in past 18 months.

I am going to replace the other caliper and bleed the whole thing again tomorrow.

My location is NY. I hope this doesn't happen again in another year.

holy fuck you used ATE Super Blue fluid? ...that MIGHT just be your problem there. Super Blue is a DOT5+ fluid. Which means it has a higher boiling point, and the pressure is not suitable for extended use on a street car.

A lot of people say its ok for a street car, but iv seen plenty of brake failure of Daily driven cars due to that fluid.

Its not a bad fluid by all means, its awesome. But its use on regular street where you don't get up to good temps in the brake lines may cause wear.

I wonder if even your calipers are broken at all with that fluid still inline. I suggest bleed the brakes and switch to a DOT3/DOT4 fluid, and not a racing fluid.

But if you believe that the fluid is not the cause, then ignore my post.

[#87]

I have the caliper I took off today. Before I return it for core would I see anything of benefit by pulling out the piston and seeing what it looks like?

Is there any reason why the rear calipers would go bad from the fluid but not the fronts?

[WingsofWar]

Brake bias makes you work the front brakes more, which loads it up and generates a bit more heat than the rears.

My guess, If it really is indeed the fluid, your not getting good pressure in the rears because your not reaching optimal fluid temps from load. AKA your fronts brakes doing more work than they should.

Having unequal pressure for a long time could damage those rear calipers...

[#87]

Hmm, that is interesting, I didn't know fluid could cause these problems. The bottle says DOT4 and that it meets/exceeds/compatible with DOT3/4.

What is a good high temp street fluid then?

[WingsofWar]

Originally Posted by #87

Hmm, that is interesting, I didn't know fluid could cause these problems. The bottle says DOT4 and that it meets/exceeds/compatible with DOT3/4.

What is a good high temp street fluid then?

DOT4 is rated at 446Degrees F, which is really more than you need on a street car especially an Accord Sedan with factory calipers.

Your ATE Super Blue is rated at 536Degrees F, which makes your brakes run too cold for daily use.

ATE Super Blue Racing Brake fluid is actually not officially DOT rated, but have similar qualities of DOT4 being a high temp and a polyethylene glycol base. The reason why it says compatible is because you can mix it with other brake fluids, ie; if you have DOT3 fluid in your system and your running low, you can add ATE Super Blue and it will slighty raise the boiling point but not degrade the quality of the fluid.

So any over the counter DOT4 brake fluid at the store should suffice, and give you good performance.

[#87]

I guess I didn't know that Brake fluid had a minimum operating range as all the fluids only list maximum temps (well minimum boiling).

I will get this tomorrow then. http://www.autozone.com/autozone/acc...entifier=21051

Thanks for the help, at least I learn this now and not on the brz/frs

[ichitaka05]

Yeah, DOT3 is good enough for DD car

[4agze]

Had same problem in my g20 sticky rear brakes changed pads, rotors, calipers turned out it was my brake master cylinder

[Neutral_Eyes]

I alternate between ATE Super Blue and Typ 200 and haven't had any problems with them on the street.

[Dave-ROR]

Originally Posted by WingsofWar

Your ATE Super Blue is rated at 536Degrees F, which makes your brakes run too cold for daily use.

BTW, this is completely wrong. Fluid can boil at x temp, it's a hydraulic fluid that flows perfectly fine at ambiant temp.

I've used ATE Super Blue and Typ200 for almost 12 years, hundreds of thousands of miles, and a lot of Motul too. They are perfectly fine for street use and great for the track too.

[WingsofWar]

Originally Posted by Dave-ROR

BTW, this is completely wrong. Fluid can boil at x temp, it's a hydraulic fluid that flows perfectly fine at ambiant temp.

I've used ATE Super Blue and Typ200 for almost 12 years, hundreds of thousands of miles, and a lot of Motul too. They are perfectly fine for street use and great for the track too.

Cool! iv known some people that have used high boiling brake fluid ATE also for several years with no problems. While others i have seen had braking issues because of the fluids. The cars varied from 1986 Honda accord to 2005 ford escort, and many others. And the problems have gone away for many of those cars by switching to a lower grade fluid ak DOT3/DOT4 standard.

You could be completely right that the fluid is not the problem, and that all brake calipers works at any normal hydraulic temp. And i am completely wrong. But from my personal experiences It does make me question the validity and application of that fluid in certain situations or for right conditions.

I can only give advice to others that iv seen and witnessed to do good, and not give harm to anyone. If its wrong, then no harm done.

[Dave-ROR]

Between myself and the other 50-60 track guys I talk to often, no one has ever had any issues like that. I usually change to super blue within 1,000 miles on all of my cars (because that's about how long I own them before tracking them the first time). So just on two of my current cars that's about 275,000 miles of super blue usage

[Random_Art]

ok... here's a question. What's the best procedure for changing out the brake fluid? Draining the master cylinder and refilling it with fluid of choice and then opening up the valves on the calipers to push through the new fluid?

[Dave-ROR]

I never drain the MC res first, out of laziness. I just bleed it through the system.. again being lazy. Or use a vacula :P