Guest rjohnson
Hi there, I was wondering if switching to silicone based brake fluid would give me any better braking performance in my 2004 corolla S.
Hi there, I was wondering if switching to silicone based brake fluid would give me any better braking performance in my 2004 corolla S.
Nope - don't use silicone fluid. Granted, the brake fluid does have higher temperature performance, but only for systems that can take advantage of that fluid type. Compared to DO 3/4 glycol based fluids, silicone based brake fluids have definite pros/cons.
PRO
- Won't damage paint
- Won't aggressively absorb moisture
- High heat performance
CON
- Neither absorbs or dispeses moisture (can't tell if there is moisture in there or not, can accelerate corrosion in the brake system, requires frequent fluid changes)
- Has much high compressibility compared to Glycol based fluids, can give unusual pedal feel
- Silicone fluid aerates aggressively, if aerated, braking will be non-existent
- Does not have the lubricating qualities of glycol bases fluids, can damage ABS systems
If you feel you need a high performance brake fluid - better to go with a DOT 4.1 synthetic fluid, all the high temperature benefits of silicone, but glycol based like the DOT 3/4 stuff.
That said, brake fluid only makes up for a small fraction of the overall braking performance of the car. If you need something that will improve braking performance, better tires and upgraded brake pad materials will give you the best bang for the buck here.
Dan_H
Don't mix silicone brake fluid (DOT 5) in systems made for glycol based brake fluid (DOT 3, 4, 5.1).
If you're asking for track use or anywhere the brakes will be used repeatedly without having a chance to cool off, such as mountain drives, look for the higher temp fluids, bleed/flush the brake system more often, and consider pads/rotors suitable for higher temperatures. I know people who change brake fluid before AND after each track day.
I'll assume you're asking from a street-safety standpoint. For general street use, the dry and wet boiling points are usually less critical than rate of moisture absorption. The fluids made for extreme temperatures tend to degrade faster when absorbing moisture-- one of the reasons they need to be changed frequently. If you won't be bleeding the brakes very often, look for something with low moisture absorption. I typically use Castrol LMA(Low Moisture Activity), which exceeds DOT 4.
For overall stopping power: if ABS is kicking in, the grip between the tires and the ground is the limiting factor. Better, fresher, and properly inflated tires have more impact in this case. Most non-ABS cars that I've autocrossed (and pushed the braking limits of) are front biased, meaning the front wheels will lock before the rear wheels. This makes it harder to spin cars while turning and panic braking. Experienced track and autocross drivers sometimes put more aggressive brake pads on the rear to even out the bias, but I wouldn't recommend it for street use. I have a car with an in-dash bias adjuster, and things can get pretty hairy with too much rear bias.
You can find more aggressive street-use pads for all wheels. They may improve brake 'bite' and overall feel, but keep in mind that they will generate more dust, be more likely to squeal, and be harder on the rotors. If your stock brakes can lock the wheels at peak temperatures, more aggressive pads won't make you stop any faster. Avoid high temperature brakes for street use, since they don't work well at lower temperatures.
For best all-around street braking performance:
If you want an OTC great brake fluid, look at Castrol LMA (pepboys). Bleed the brakes and make sure you purge all the old fluid.
Not sure if you are looking for more bite, but Akebono pads with Brembo Rotors are probably the best braking combo, but of course the is a very large price tag. As pointed out, that combo is not great in the cold weather. If you do not race your car, stock pads and rotors are fine for everyday use. Flush/bleed the brake fluid every 2 years.
