Refilling Brake Fluid (Newbie)
 

I have searched for this and could not find anyone in my situation, but I think that its a pretty simple question, just want to be on the safe side thats why I'm posting this. Anyway! My brake fluid is down past half (making me think thats why my brakes are sqeaking) and I wish to refill or "top off" my master cylinder so that it is at it's max amount (was in manual). Except in the manual it doesn't say which type of brake fluid to put in it. I bought "Prestone Synthetic DOT 4" brake fluid, which says "Good for all DOT 3 and DOT 4 brake systems" and that "Compatiable with all conventional brake fluids". Is this the correct fluid for my rx-8? and if I mix it with whatever brake fluid is currently in my car will there be any repercussions? Any help or advice on what I need to do would be great thanks all.

you can mix fluids that say compatible with dot 3 and dot 4 with the stock fluid which i think is dot 3.

its even better to flush the system and replace with new fluid. even after two years there is a lot of water in the fluid. i just did this myself. you can do it yourself with a $3 tube and bottle you get at the parts store- this lets you pump the pedal without being at the bleed valve too.

the low brake fluid doesnt make your brakes squeak.

james

Don't top off the brake fluid. It is normal for the level to go down as the pads wear. When you eventually change your pads, the level in the master cylinder will increase and will overflow. The brake fluid will then dissolve the paint on any underhood body component it touches.

Also, like Ophitoxaemia said, there is no way the low brake fluid is causing the squeeking.

>When you eventually change your pads, the level in the master cylinder will increase and
>will overflow.

been there, done that. good point.

but it can get low enough in my other car to trip the low-brake-fluid light, which is annoying. dont know if that will happen in the 8.

james

do a quick check on your pads...then if you see that you have plenty wear left...welcome to the squeak club...it's OEM from Mazda...:)

I say go ahead and top it off, then when it is time to change pads, just use a turkey baster (sp?) and remove some of the fluid so it doesn't overflow, has always worked nice for me.

If it's really low...you either have a leak...or really worn pads. Check for both before you add too much fluid.

If it's a bit low....top it up...

and remember...if you need new pads...it's a great time for new fluid too :)

Hey guys !

I have few questions, seems this will be the right thread to post, no need to make a new one.

1)Is it possible that when the brake pads are low the (!)Brake light is on ? (like the one with hand brake)

2)Is it possible that when the brake fluid is low the (!)Brake light is on ? (like the one with hand brake)

3)Which brake fluid to use ? My service manual says something like this: "SAE J1703 or FMVSS116 DOT 3" - what does this mean ? Can i just grab any DOT 3 fluid and mix it with the one i have or do I need to buy some special fluid for RX-8 ?

^ We don't have a worn brake pad idiot light. We do have (stock) a mechanical clip on the passenger rear inboard pad that rubs against the rotor when very worn and causes a screeching sound. 'course none of us here will ever get to hear that sound, since we often check our pads. ;)

Any DOT 3 is fine.

As the pads wear down and the caliper piston moves in to compensate for the thinner pad, the fluid level drops as a result. If you fill the fluid to the max when new pads are put in, and if there are no leaks, the fluid level is a rough indicator of pad wear and the low fluid light is an indicator of either a leak, or more likely, routine pad wear nearing the replacement point.

You can use either DOT3 or DOT4 fluid as a replacement. As others have said, the fluid level has nothing to do with brake squeeking per se, that's all in the pads. Old pads tend to squeek more than properly installed new ones because the lubricant on the backs of the pads wears off over time unless you periodically replace it. I relube my pads when I switch in/out my track pads for HPDEs about every 3 months so neither my OEM pads or my track pads (Cobalt XR2s) squeek. Nobody has to have squeeky pads, just periodically lube the back of the pads with molybdenum disulfie synthetic brake grease (the black stuff).

Yea i know that as the pads wear down they will start to squeek but lately few times the (!)Brake light was on aldow i didn't use my hand brake so i was just wondering what is the cause of this.

Thnx for the answers

If that light is coming on and the hand brake is down, I would check the switch.
Lift up the center console and the switch is located right in front of the hand brake.
Below is a pic that shows the switch (I know I know, my console is dirty :))
Attachment 144085

^ I'm shocked and dismayed my learned fellow member. ;)

btw: the "just yank the cover via the boot" method works well, despite the natural hesitation to do so.

Thnx, i'll take a look under the console :P

I've just heard an opinion that the light may come on as the fluid / pads are low so i just wanted to make sure;P

if you change your brake fluid, you might as well use the dot 4, not that much more expensive!

just in case anyone is still looking at this thread before I go to start a new one, would anyone happen to know how much fluid the brake system will take with a complete flush (yes, i've searched with no luck, but I apologize if this info is out there somewhere)?

...looking to change out to the dot 4. Thanks in advance for your help!

you can do a full bleed with a quart...but it's touch and go to do it properly...

I would buy 2 just to be sure.....

If you use a different color it's easier to tell when you have bled out all the old fluid...

I like Ate Super Blue and Ate 2000....one is blue and the other amber.....

Thanks, dannobre. Appreciate the info!

If you have a 2004/2005, the master cylinder has a bleed screw. Use it, it makes purging air out of the system a breeze.