Thinking of replacing the brake fluid in my car (have a few track days on it) and in the past on my other track cars, I've usually used Project Mu G-Four 335 or Torque RT700 brake fluids.

My issue is that I don't want to run afoul of warranty issues with the ABS system, etc.

What are the Porsche approved brake fluids? I assume there's a Motul product? Or should I just stick with OEM (which seems to be very good).

Thanks.

 

Porsche uses Endless in their race cars and I think it's great stuff...

 

Does anyone know what is the stock brake fluid that comes in the GT3???

 

Porsche sells their own brake fluid called the super dot 4 with part number 00004320366. not sure who makes it for them, but in general any dot 4 fluid will work without impacting the warranty terms.

 

Castrol SRF racing is what comes in your car.

 

Porsche GT3 OEM is SRF? I don't believe it...

 

I heard something similar...

 

I'm pretty sure it's regular Porsche DOT4 fluid which I understand is comparable to ATE 200. I'd be very surprised if it were Castrol React SRF or comparable.. Suncoast lists Porsche DOT 4 fluid on their site for the GT3 for 28 bucks/ liter. SRF costs over twice as much. I've had no issues with boiling on track with the factory fluid, but if going hard for long stints say at COTA, switch to SRF would make sense.

 

So would you rate the react SRF racing fluid as the best braking fluid in the market?

 

I'm no expert and there are various opinions. But Castrol react SRF has among the highest wet boiling points of any fluid. I got a soft pedal on a hot day at TWS going into T2 (Cayman R at about 135mph) this past summer. Switched to SRF for the next event. It's expensive but 2 bottles is still less than a set of pads, way less than tires, so minor cost in the big picture. IMO.

 

Had the system been flushed within the last 12 months? I just had mine flushed with ATE 200 and no problems. There're plenty of fluids with higher specs but I've never had a problem but then I'm a poster child for HWFMR

 

Dealer had flushed the fluid a week or so before but not sure how fresh the fluid they used was. To be fair it was a hot day in Aug, front pads (Pagid yellow) were below 50% thickness, Cayman R brakes are smaller than GT3, I was on NT01s for the second weekend, and was pushing a bit when the brakes went soft. Didn't like that at all.

In the GT3 I don't push very hard. I only have the sofa seats and 3 pt belts and I self impose a speed limit on the front straight. With the bigger brakes have not had an issue with the factory fluid.

 

I just double checked, and please stop spreading the rumor. according to the factory parts catalogue for the 2014 991 GT3, KAT 541 MG 6 SG 04 Illustration 604-00, it states the factory brake fluid is Dot 4 and required amount is 1 liter. the part number listed there is 00004320366, which I have stated earlier and is called the Porsche super dot 4 brake fluid.

 

Its one of the best along with Endless/Motul etc. The reason I use it is because its ubiquitous at the track (i.e. virtually everyone I know uses it so its always easy to find a bottle to top up/flush should I leave mine at home. Not that Ive ever needed too yet!

 

gonna try and change my fluid with castrol SRF