I ma running Project Mu G-Four fluid with Ferodo DS2500 pads in front and Project Mu HC+800 pads in back. A beautifully balanced system with GREAT stopping power, pedal feel and fade resistance. All bought from SpeedFreaks. Good Stuff

Lou

 

If you go from dot 3 to dot 4, is it advisable to flush the system completely with techstream or can you do a regular drain and refill as you do with a regular change?

 

Get tech stream on eBay for $20 with cable and flush it yourself. I use an old netbook running XP

 

I went from DOT 3 to DOT 4. I flushed using the old fashioned method, except I used Earl's Solo Bleeders. The Earl's replace the stock bleeders and make the job easier. To make sure all was purged, I bled the first caliper twice.

All has been good

Lou

 

I flushed out using 2 oem toyota bottles... ive used motul in the past with great results however on this car the brakes seem really good already and I've never ran into any issues with the stock system therefore I went with the oem fluid. I wouldve went motul, but I didnt need it since I dont plant to track it to get most use out of it. Heard the motul came out with an updated model called rbf 660

 

DOT 3 fluid is just fine. DOT 4 was originally developed for English cars with Girling brakes. Girling used natural rubber seals, and DOT 3 would eat through them. DOT 4 does not. I wouldn't call DOT 4 a "higher standard" it's just different. On the plus side, if you can run DOT 3, you are good for DOT 4 too, but not vice versa. Most of the higher temp fluids are DOT 4.

I run Brembo LCF in mine. I have had zero issues with it, and I installed Earl's solobleeders when I first got the car to make bleeding brakes at the track easy. Despite all this, I managed to boil my fluid on my first track day because I left the nannies on and drove way beyond what I should have. It is rather amazing how much the nannies will let you do when you are right foot heavy and not in tune with what the car needs.

 

I just want to clarify since there seems to be a lot of confusion about the grades.

lobuxracer once again brings some good information to the table. He is right and perhaps I phrased my initial comment wrong- I should have said DOT 4 carries a higher minimum standard than DOT 3. A fluid needs to have minimum dry and wet boiling points of 446*F and 311*F respectively to carry DOT 4 grade vs the minimum dry and wet boiling points of 401*F and 284*F respectively to carry a DOT 3 grade. However, as lobuxracer started to point out, the grade alone doesn't necessarily mean you're getting a better product. Not all DOT 3s and DOT 4s are created equal and there is a large delta in the performance of fluids in each grade. It is true that there are some DOT 3 fluids that outperform some DOT 4 fluids. Those DOT 3s that exceed the minimum DOT 4 boiling points cannot be considered a DOT 4 because of the chemical composition. It is irrelevant for the IS-F specifically since it can use a DOT 3, DOT 4 or DOT 5.1 without issue but he brings up and important detail that if the manufacturer calls for a DOT 4 you can get yourself in trouble by flushing with a DOT 3 as they are different fluids and the DOT 3 may not play nice with the materials inside your braking system.

The bottom line is that it is up to the consumer to determine what they need. There are a lot of options out there but we try to make life easier by offering only top tier fluids that we know will work in your street or track car.

-Matt M.

 

Ugh...lol. I'm kind of more overwhelmed now...okay The ISF comes with stock Dot 3 fluid. The manual doesn't say to replace brake fluid with Dot 4 or 5. It says replace with brake fluid SAE J1703 or FMVSS No.116 dot 3. I want to purchase project mu hc 800 pads to eventually move up to endless pads in the future. I want the brakes to perform accordingly but I don't want to upset or damage anything in the braking system. I don't care for the cheap stuff as I don't want to degrade the cars performance. But I also don't want to introduce it to something I can possibly damage. I want more performance but I'm thinking it will probably be best to stick to OEM now...lol...🤔🤔🤔🤔

 

Use motul dot 4 and up its good for break fluid

 

It comes with DOT 3 fluid but can use DOT 4 or DOT 5.1 if you like. All this means is that you have no restrictions when it comes to what fluid you can use. If you plan to run Project Mu HC+800 pads use them as they were intended to be used (aggressively ) then we recommend you also flush your fluid with Endless RF-650, PFC RH665 or PMU G-Four 335... All of which are among the best fluids you can buy and all of which are safe to use in your car. They will not damage anything in your IS-F's braking system.

-Matt M.

 

Okay Thank you Matt! I will be getting a hold of you very soon!

 

Hey Guys, I was doing some research on brakes and came across this thread. At 145k miles I requested a brake flush through Lexus, so I’m assuming they used OEM fluid to do so. I’m at 150k mi right now, and June 13th is my first track day. I was gonna change out the pads to a more track oriented spec, However I’m teetering between getting new brake like motul 500 or tracking with my relatively new fluid, only around 5k miles old, more or less. Insight? Thoughts? Should I be good to go or should I change my fluid to a higher temp fluid? Thanks everyone

 

I ran OEM brake fluid on a short track day, and then changed it to motul on another track day. As much as I think you'll hate hearing this...there was a significant difference with the motul fluid, and that was on a short lap day, typically 3-4 laps followed by 30-45 mins cool down. If you're lapping for an extended amount of time, the motul will likely mean the difference between boiling the fluid versus not.

 

You'll be fine with your current set up. The most important thing about brake fluid is boiling point. Over time, brake fluid absorbs moisture. It is designed specifically to do this so moisture won't collect in the brake system and cause corrosion leading to brake failure, the only exception being DOT 5 (not 5.1) because it is pure silicone fluid and does not absorb water at all. So, the fluid you put in recently is still pretty fresh and still likely not too contaminated with moisture. It would honestly outperform most the the so-called high performance fluids if the difference was you have fresh fluid and someone installed a high performance fluid a few years ago (or much less time if it is like Brembo LCF, as it deteriorates very rapidly compared to any of the street oriented fluids).

I had an HPDE instructor tell me he ran the cheapest possible brake fluid simply because the brakes would go spongy before the pads were anywhere near fading and it told him to back off a little. Pad fade means you will find stopping nearly impossible. Boiling fluid means if you pump the brakes fast, you'll get some pedal back and your pads are still not too hot so they'll work. It's all a trade off.

 

thanks for the reply, by current setup do u mean current fluid with track pads, or current fluid with my street pads. Last thing I wanna do is destroy my pads and then have nothing to drive home with!