I just got power stop rotors and axxis pads. the rotors call for DOT 4 brake fluid while my 97 maxima calls for DOT 3 . Which one should I use? I think I should stay with the DOT 3 since it's made for my car, but I do not know. Thanks in advance. BTW I do have ABS, not sure if that matters

 

The only difference if the boiling point. Dot 4 can run hotter. If your going to puch your max and get the brakes smoking hot, then use dot 4. If your going to drive normal and just take advantage of some nice brakes, stick with dot 3.

 

NO, THIS IS WRONG. (I'm not trying to be a ***** but the point needs to be understood, DOT 4 in a 4th gen Maxima will ruin the braking system).

First, the brake fluid has absolutely nothing to do with the rotors. I don't know where you got the info about using DOT 4 with powerslot rotors, but its a total lie.

Second, DOT 4 fluid is silicone based fluid, whereas DOT 3 is petroleum based. Silicone based fluid will ruin the gaskets and seals in your braking system if they are not designed for DOT 4 fluid.

If you are interested in having fluid with a higher boiling point than stock, go to your local Ford dealership and get Ford heavy duty/high performance DOT 3 fluid. Its dry boiling point is about 100 degrees higher than normal DOT 3 fluid, but the wet boiling point is approximately the same. You don't need to worry about wet boiling point however, unless you have a problem with your braking system and water is getting in the fluid. I have Ford HD fluid myself, and I road race and autoX quite a bit. I have never experienced boiling of the fluid, and road racing is the ultimate test of a brake system, mine's worked like a charm.

 

[QUOTE]Originally posted by Nealoc187
[B]

NO, THIS IS WRONG. (I'm not trying to be a ***** but the point needs to be understood, DOT 4 in a 4th gen Maxima will ruin the braking system).

First, the brake fluid has absolutely nothing to do with the rotors. I don't know where you got the info about using DOT 4 with powerslot rotors, but its a total lie.





UUUUUHHHHHH....

Not trying to be an a$$ but power stop says "power stop recommends you flush your brake fluid and bleed the entire system with a high grade DOT 4 or better fluid"

this comes off there little yellow instruction sheet that comes with the brakes.

but AGAIN i asked the question, because i don't know the answer. in the FSM it says use DOT 3 , and nothing else. So that was fine , but power stop said DOT 4. thank you for clearing up the difference between the two. i had no idea it would hurt the system that bad. anyway thanks for the help and DOT 3 is what's going in

 

uh, ACTUALLY Dot5 is the silcone based fluid, Dot4 is the same as Dot3 but a higher boiling point. Using Dot4 in your system will NOT ruin ABS nor your regular hydraulic system. Dot5 WILL tho. I think you juss got the numbers confused. Wet boiling point is important because brake fluid is hydruscopic(cant spell) it absorbs moisture so eventually moisutre is in the system and thats one of the reasons we have to change brake fluid.

 

Yes, DOT 5 is silicone based and is not compatible with DOT 3 or 4. I use Castrol DOT 4 LMA (low moisture absorbsion). Keep in mind that as a brake fluid absorbs moisture, it's boiling point drops considerably.

 

If you're bothering to change fluid, always go to a DOT 4 for the higher boiling point. Like some others said, DOT 5 is the silicone one that will damage your system.

The reason Power Stop recommends DOT 4 is they assume since you are interested in rotors that run cooler under heavy braking, you will be driving the car hard and a DOT 4 fluid will resist boiling to a higher temp, preserving pedal feel. You do not NEED to change the fluid, DOT 3 will work. If you brake hard though, DOT 4 is worth the $10-15.

 

[QUOTE]Originally posted by bags533
[B]Like I said, the brake fluid has nothing to do with the rotors, but I understand that it says to flush the fluid, because if your rotors need to be replaced its likely that the fluid is kinda old too, that's normal.

I was under the impression that you meant it needed to be a certain type of fluid or it wouldn't be compatible with your rotors or something, I misunderstood you.

Yep, it looks like I did get my DOT 3s and 4s and 5s confused, forgive the misinformation, and thanks for correcting me so I don't look like an idiot again.

Anywho, as I said before, I was NOT trying to come down on you hard, I was trying to make a point which I felt was critical so that you didn't ruin your braking system. Too bad I had my numbers mixed up and just ended up looking like a dumba$s. Sorry.

 

I really don't see why bleeding the brakelines are necessary since you are not going to open the system at all, but why not bleed them since you're down there anyways. I was thinking about going to DOT4, but I searched on a number of sites to figure out what to do. People who have tried both, in hindsight, suggest you use a DOT3 that resists moisture...some of these get pretty pricey (relative to others). I decided to just go with the Ford High Performance DOT3, it was only $3.50 a bottle and I think it took 3 bottles to do the job (I openned the brake system and rebled 6 times or so).

My Wilwoods finally settled and my brake pedal feels better than ever. It took about 400 miles and a bunch of bumps, but I think all the air is out of the system. I hit a railroad track, my brake light went off, and my pedal firmed up a lot. I checked the resevoir and my fluid was low. I just filled it up and everything is great.

 

Kevin. Some of the DOT 4 stuff is pricey. That Ford HD dot 3 is really good stuff also. I found Valvoline DOT 4 at the local auto store for a good price though. So I went with that when I flushed my brake system. I think it had the original fluid! (130K miles!)