Brake fluid question

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Would there be any benifit to using dot 4 over 3 in my cruze? I assume its oem fluid. Has 90k. I heard dot 4 is less hydro something meaning it absorbs less water over time vs dot 3. That would be a benifit to me. Im also tuned and i guess once a month it gets driven spiritedly. I did a quick stop from 110 mph down to 60mph and it had terrible terrible brake fade and it was mush for a few miles. Pads and rotors are good on front and rear drum has good shoes and adjusted right. Im thinking i over heated my fluid. I know its time for a fluid change and just debating on dot 3 or 4. Also the clutch shares the same resivor as the brake fluid.
 
I'd say it can't hurt to try, especially if the price is right. At the very least, it'll give you a very good bleed. I get Castrol LMA DOT 4 for cheaper than DOT 3 examples, so that's what I went with.
 
Some claim that DOT 3 takes on moisture slower than DOT 4, despite having a lower wet boiling point, so who knows.
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You could always use the good old standby, Ate Typ 200, which does actually claim to take on moisture at a much reduced rate vs. other DOT 4s.

Was it ONLY the RS version of the 1.4T Cruzes that got the rear disc brakes (or did even those come with drums)?
 
I have the rs package. Its the trim package that did inteiror stuff and better brakes/ bigger rims. I have the lt1 i think the lt2 has the better stuff
 
Originally Posted By: Dylan1303
Would there be any benifit to using dot 4 over 3 in my cruze? I assume its oem fluid. Has 90k. I heard dot 4 is less hydro something meaning it absorbs less water over time vs dot 3. That would be a benifit to me. Im also tuned and i guess once a month it gets driven spiritedly. I did a quick stop from 110 mph down to 60mph and it had terrible terrible brake fade and it was mush for a few miles. Pads and rotors are good on front and rear drum has good shoes and adjusted right. Im thinking i over heated my fluid. I know its time for a fluid change and just debating on dot 3 or 4. Also the clutch shares the same resivor as the brake fluid.


Seen it claimed that DOT 4 is indicated for ABS systems for the lower viscosity, and for performance cars for the higher dry BP and the chemical heat resistance of the borates in it.

These properties are supposed to compensate for its higher water absorption, since you are supposed to, like, change it before this becomes an issue.

I don't have ABS, its very humid here, and I don't have a high performance car, so DOT3 wins for me, plus its about half the price.
 
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The most important thing is that you change the fluid regularly. Most cars go to the junkyard with the original brake fluid and never get it flushed

If you want something with a higher boiling point, consider something like Bosch ESI6 or Ravenol DOT 5.1

Pep Boys caries Wagner Severe Duty brake fluid for about $15/qt
 
Originally Posted By: Dylan1303
Would there be any benifit to using dot 4 over 3 in my cruze? I assume its oem fluid. Has 90k. I heard dot 4 is less hydro something meaning it absorbs less water over time vs dot 3. That would be a benifit to me. Im also tuned and i guess once a month it gets driven spiritedly. I did a quick stop from 110 mph down to 60mph and it had terrible terrible brake fade and it was mush for a few miles. Pads and rotors are good on front and rear drum has good shoes and adjusted right. Im thinking i over heated my fluid. I know its time for a fluid change and just debating on dot 3 or 4. Also the clutch shares the same resivor as the brake fluid.

Use ATE TYP200 DOT4 fluid and call it a day.
 
Originally Posted By: Marco620
Dot 3 lasts longer,Dot4 has better performance but needs changing more often.

How long? What is longer?
Brake fluid is cheap, very cheap to talk about few months of difference between 1 and 2% of moisture.
 
1 stop from 110 to 60 should not have any impact on pedal feel, I'd be tempted to change fluid, discs and pads and get them bedded in properly before trying the 110-60 again.

If you noticed that much fade after one deceleration there's a real risk of something damaged or not functioning correctly in your braking system. At the very least repeat the conditions after new fluid and see if you can replicate the fault.
 
After 6 years it is definitely time for fluid change...manual probably states every 2 or 3 years. This could explain why your pedal is soft, but maybe not. I have owned cars where the brakes were just softer than others. Either way, I would just use what the manual specs (probably dot 3). Or Valvoline Dot 3/4. Just keep up with fluid/pad/rotor changes and you shouldn't have any problems in the future.
 
Originally Posted By: Marco620
Dot 3 lasts longer,Dot4 has better performance but needs changing more often.


That's not true.

One of the main benefits of DOT4 is that it has a higher wet boiling point.

shell-dot-fluid-boiling-points.png
 
I use DOT4 on non-abs brakes and I use DOT4 low viscosity on ABS brakes. That is because DOT4 is cheaper than DOT4 low viscosity, and DOT4 low viscosity mostly exists so the ABS module can react faster.

Typically I use Valvoline DOT4 and I use Pentosin DOT4LV low viscosity.
 
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