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Brake fluid recommendation

7K views 16 replies 6 participants last post by  GKR_Nik 
#1 ·
Hey folks. I currently have the ATE Super Blue brake fluid in my car after I installed a 4xBBK a few years back but the fluid is no longer available. I am about to remove my calipers for powder coating and the mechanic said I will lose a lot of fluid so I need to replace it. Any recommendations? Many thanks!
 
#2 ·
Unless you track it, any DOT3/4 fluid is good. If you want the best fluid you can buy, get Castrol SRF. It's what I use for my track cars.

Best not to mix.

If you let the ABS unit run dry, you'll have a hell of a time bleeding the brakes. You're better off capping off the end of the brake lines than letting the system run dry.
 
#8 ·
Mixing is fine as long as they're all glycol based as all DOT 3/4/5.1 are. The issue is just that it will only perform as the lowest performing fluid.

Brake fluid is hygroscopic, it absorbs moisture, at 3+ years, it should most certainly be replaced. Having blue fluid will make it easy to flush the system. Just keep pumping until it stops coming out blue and starts coming out amber.

ATE still makes a fluid, it just doesn't have a dye anymore. However, off the shelf Valvoline DOT4 actually has a decent boiling point, is easy to find, and is cheap.
 
#4 ·
Wow that is very good to know. I don't know what the mechanics' plan is but it sure sounds like he is going to let it run out. I will let him know. Thanks so much brother!
 
#6 ·
I don't know what the mechanics' plan is but it sure sounds like he is going to let it run out. I will let him know. Thanks so much brother!
Brake bleeding procedure requires a specific ABS block bleeding procedure to do it properly. It's a bit of a pain. It's just much easier if you don't let the system bleed out.

For an empty system, I usually have a couple quarts of fluid on hand.
 
#11 ·
Dot 5 is a pain to get the air out of. Takes a lot of time to bleed well.
Dot5 is pretty much dead. It's not compatible with ABS systems. On the other hand 5.1 is still alive. I've never actually seen anyone use it. Considering you can get fluid like SRF, I'm not sure why anyone would want to use DOT5 over a high end conventional fluid.
 
#15 ·
As has been hinted at, the "best" fluid for you depends on what you are doing with the car. If you are just DDing, it's whatever 3/4 is readily available. If you are doing some spirited driving, perhaps in the mountains, you will want a higher end DOT4. There are lots available, Motul RBF600 is probably the most popular these days. Fluids like Torque and Castrol SRF are the best of the best, but they are also ridiculously expensive. I've never had a racecar that didn't work perfectly with Red Line RL-600 or Motul RBF660.
 
#16 ·
Fluids like Torque and Castrol SRF are the best of the best, but they are also ridiculously expensive. I've never had a racecar that didn't work perfectly with Red Line RL-600 or Motul RBF660.
I liked the SRF because I could flush the brakes at the beginning of the season and not have to dick with the brake fluid the rest of the year. Some other fluids might be up to it too but for a once a year change, I didn't look around for any other brand.
 
#17 ·
True dat. It's (semi) cheap insurance.

I'll make an analogy to towing. If you have a single axle aluminum open trailer with nothing on it, you could tow it with a Geo Metro. You could also tow it with an F650. If you have a three axle enclosed gooseneck with 4M in gold bars and three mini coopers in it, you will need that F650.

SRF is that F650, El Cheapo DOT3 is the Metro. It all depends on what you are towing. You want to give yourself enough of a buffer that you aren't cutting it close, but also don't need to be spending crazy money for the best of the best when your application doesn't even come close to demanding it.

I've only just started on the IS, and I haven't brought it on track yet, so you have more data that I do. I will be using stick-on temp meters on the calipers, so I can get us some accurate feedback on the actual demands of the braking system.

One more example is my Miata track car. Of course, at 2100lbs it's way lighter than an IS, and less powerful. Further, I have a big ol' Wilwood two piece rotor and aluminum caliper on the front end to dissipate heat. With that setup in that car, I tracked for three years on Motul RBF600...not even the 660, before I felt like I should change it out just on principle. That is to say, it wasn't fading or getting soft yet.

Just food for thought, there's nothing wrong with using SRF, I just like to count my pennies :smile2:
 
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