brake fluid
 

I believe I understand the advantage of DOT4+ synthetic brake fluid (higher boiling point). I understand this is important if you are rallying the car (which I do not) when temperatures would be more extreme. I have a couple of questions.

- Is the synthetic worth the extra money (I am replacing rotors, pads, and brake lines)?
- How much fluid does it require, since I would have to bleed the entire system?

And the age old question regarding pads. I am leaning towards the Akembo ceramics because they are quieter, less dust, and less harsh on the rotors, and longevity.

- do the ceramic's performance decrease apprecaibly when they are wet? what about cold?

thanks in advance.

r/-cas

When I replaced all of my brake fluid to new after doing what you will, I think I used less than 1 Quart. Doesn't take all that much. The most important thing is to change it ever year or so because it picks up moisture which isn't good. I have never replaced it every year, but when it starts to get dark, I do it then. :)

I don't believe the synthetic is as hydroscopic as "regular" brake fluid, thus potentially saving you future issues with "crap" in the brake lines and calipers. I'm switching my system over to synthetic as soon as I get my rebuilt calipers and s/s lines for the back brakes.

DOT 5 fluid...
 

Be aware that most auto makers do not recommend switching over to DOT 5 if the car previously had DOT 3/4. This is because DOT 5 is incompatible with DOT 3/4, and it is impossible to remove all the old fluid from the system, even with repeated flushes.

You'll have nothing to gain and a lot to lose by changing to synthetic. DOT1,2,3 &4 are not compatible with DOT 5 (synthetic.) This means that every rubber part in the system must first be replaced and all the remaining steel parts thoroughly flushed. Yes, there are rubber parts in the ABS pump, so plan on either deleting it from the system or buying a brand new one. Then again, anyone that needs DOT5 wouldn't want an ABS system as repeated testing has shown over and over that ABS systems don't/won't stop as fast as non-ABS systems.

BTW, not to pick nits but the proper word is 'hygroscopic'. :) As I recall DOT5 is even more susceptible to moisture than DOT4. You may want to check into that, I have been wrong once or twice before. ;)

all righty, now!
 

That puts the DOT 5 to rest. I appreciate the help.

To bring up the pads again. I have read through most of the archive on brake pads and I am still confused. I am looking at the Akembo pads for longevity, quietness, ease on the rotors, etc.

I live where it is wet most of the year, and cold 1/2 the year. :D

How do the ceramics behave in the wet, and in the cold?

r/-cas

Thanks, Beav....should have stayed with "tend to attract water" and not trusted my questionable spelling skills :rolleyes:
I went out and checked the fluid I bought from AutoZone and it's Valvoline's "SynPower - synthetic formula". Reading the label closely, it is actually a DOT 3/4 fluid that "Meets and exceeds specification SAE J1703, FMVSS No. 116 and DOT 4 Motor Vehicle Brake Fluid. Surpasses Federal Motor Vehicle DOT 4 requirements. Mixes with conventional brake fluids." It has a high dry-boiling point - up to 502 deg F. So, I guess I got caught up in the marketing on the label. Still looks like the best fluid I can find, short of going to a DOT 5 and changing out hardware.
Thanks again!!
-Bill

These days you can get all 4 rotors for under $250. Combined with an aggressive pad thats a cheap $300 life insurance policy. I used to buy cheapo pads that didn't eat up rotors to save money. Forget that. I want to stop fast when I need to. Loud, dusty, aggressive.....Good. There's nothing scarier than brake fade at the wrong time.

DOT5 and SYNTHETIC are NOT the same thing.

DOT5 is a SILICONE brake fluid... there are many DOT4 and DOT5.1 "synthetic" brake fluids like Valvoline, Motul RB600, etc. etc. that are excellent fluids.

DOT5 is only recommended for use in show vehicles as it is not a very good brake fluid, it's primary purpose is to be very paint-friendly for ultra-expensive irreplaceable cars.


DOT5.1 is the best fluid type out right now.. the Motul in particular is excellent. Their "wet" boiling points are much higher than previous types and dry boiling points can exceed 700F.