For my 2015 DB9, manual says to use is 'React Performance DOT 4'. I understand AM uses Castrol React Performance DOT 4 which I couldn't find here in USA anymore. Is there a good substitute that can be used ?

 

Check with Rich at REDPANTS.LOL He can get you whatever you need (AMAZON) but, likely will say or advise to swap to Motul product, those are his go to ones and he is a supplier of those.

I actually had Rich do my DB9 himself, and he swapped all fluids over to the Motul stuff. IMHO its no difference to me.


Side Note--- I am looking to return from AFG early 2018, and in talks with several positions in Jacksonville, Orlando, and Tampa most specifically. I will be able to personally helps those in FL in keeping their paint perfect soon I hope. Just thought I would mention that

 

Any quality fluid should work. I chose Pentosin DOT4 for my Vantage.

 

You want "Super dot 4" or dot 4+. that's what it should have, lots of makers out there. You should be able to find it at any auto parts store or motorcycle shop.

 

I used RedLine in my Evora that was good. Not sure what our AM Lotus uses. Will ask on Thursday.

 

Saw this on PH, too. Copy/paste:

I use Motul RBF600 in my red V8V and Motul RBF660 in my grey V8V. For most people, Motul DOT5.1 (or comparable) is perfectly fine.

Here's a comparison of Motul and Castrol brake fluids:
http://www.redpants.lol/brake-fluid-comparison/

The easiest way to explain wet vs dry boiling points is that new fluid is dry, and old fluid is wet. "Wet" refers to the fluid's absorption of water over time. "Dry" means it hasn't absorbed any water yet. Water doesn't withstand boiling very well, so old (wet) fluid boils more easily than new (dry) fluid. When brake fluid boils, you get steam where fluid should be, and steam compresses. That's important to know (and avoid!) because that compressing steam takes away from your brake pressure. The end result is your brake pedal goes to the floor and you still can't stop.

Bit of a tangent, but the point is that you need a brake fluid for your use. For normal street driving, Castrol React or Motul DOT5.1 work great. But if you drive aggressively, you'll want something that can handle the extra temperatures.

Also, there shouldn't be any change in pedal feel when fluid alone is changed. The main differences in fluids is how much heat they can take when new/dry and when old/wet.

 

I just bought some Motul RBF600. Production date stamped on the back of the bottles is April 2018.

If I flush now (October 2019) and expect to do my next flush in two years, will the brake fluid last that long?

(I don't track the car and put less than a couple thousand miles on the car each year.)

 

Assuming the container was still sealed when you opened it, it will last a couple of years in the car. The stuff is exceedingly stable, but also very hygroscopic. The water does two things in the brake system. First it promotes rust, and secondly it converts to steam at inopportune times, like when you mash on the brakes for the 4th time in a row. There is nothing more depressing than having the pedal go down and the car not slow...

 

I thought DOT5 is synthetic and not good to use on systems designed for DOT4?

 

Your statement of DOT 5 (silicone-based) not being compatible with DOT 4 is correct. However DOT 5 is different then DOT 5.1.

 

The label on the Motul DOT 5.1 bottle says "NOT SUITABLE FOR VEHICLES WITH MINERAL OIL OR SILICONE SYSTEMS".

Isn't the DOT4 system in a DB9 mineral oil?

 

Mineral oil is for tractors and bicycles. DOT 4 and DOT 5.1 are more or less equalivent for ABS equipped cars.

 

I am going to drain, flush and replace with silicon fluid. That will last the life of the car. I don't hot rod the thing.

 

Do not do it! It's not compatible with ABS brake systems. Just use normal DOT 4 if that's the case.

 

Yes, just did the research and you are correct. Been doing the conversion to all of my "old stuff" for so many years I neglected to consider the abs component.