What is your favorite brake fulid? I happen to like Valvoline Sythetic. It gives the car a nice pedal feel and it is good up to about 500°.

Kat

 

I used the Valvoline Syn, but I would have used pretty much what was on sale. If you change the fluid regularly, who cares what's in there, high perf or not.


Ed

 

Castrol SRF

but it is fairly expensive. and probably over kill on all our cars.

 

which is better between the 2? Or better yet, is there anything better than what is mentioned?

 

I think I have something better, but you guys may not like where you have to go to get it.

I use Ford high performance brake fluid. It has a 550 degree dry boiling temp and costs a lot less than the racing brake fluids like AP. From what I remember it costs around $3.50 for a 12oz bottle.

For reference, the highest dry boiling temp I can remember seeing in a racing brake fluid is 570 degrees.

 

Yep, I.ve heard good things about the Ford stuff.....ya traitor..

Ed

 

here is a rundown of of brake fluid boiling points. go ahead and make your own descision. remeber wet boiling point is when the fluid has become saturated with water. if you bleed your brakes frequently, you shouldn't have to worry about the wet point.

Dry Boiling Point Wet Boiling Point Viscosity @ -40°C Viscosity @ 100°C
DOT 2 374°F N/A
DOT 3 401°F 284°F
DOT 4 446°F 311°F 1800 max 1.5 min
DOT 5 (silicone) 500°F 356°F
DOT 5.1 (non - silicone) 500°F 356°F
Castrol LMA DOT 3/4 446°F 311°F N/A N/A
Ford Heavy Duty DOT 3 550°F 290°F N/A N/A
ATE Super Blue Racing 536°F 392°F N/A N/A
ATE TYP 200 536°F 392°F N/A N/A
Motul Racing RBF 600 593°F 420°F N/A N/A
Motul DOT 5.1 N/A 365°F N/A N/A
Motul DOT 4 473°F 316°F N/A N/A
Motul DOT 3 462°F N/A N/A N/A
Prospeed GS610 610°F 421°F 1525 2.5
Castrol SRF 590°F 518°F N/A N/A
Performance Friction 550°F 284°F N/A N/A
AP551 527°F 302°F N/A N/A
AP600
(not DOT approved and not compatible with any other fluids)
572°F 410°F N/A N/A
Ferodo DOT 4 446°F 311°F N/A N/A
Ferodo DOT 5.1 500°F 356°F N/A N/A
Wilwood 570 570°F N/A N/A N/A

 

The nice thing about the ford fluid is the metal container. Brake fluids can take in water through the container itself, as plastic is a porus material (especially in hot/humid environments). And it's cheap.

 

Actually, Ford has switched to a plastic container for their brake fluid. All the stuff I have bought has been in the plastic bottle since last summer.

Hey...wait a minute...plastic is porous?

Is it really? I have never heard this.

 

ford heavy duty for me...

and yea, i noticed they changed the container..... wahts up with that!?

 

best example i can think of is to take a plastic pop bottle out of the fridge. you'll notice condensation on the bottle after it's been sitting awhile.

 

Plastic is less dense than metal, which allows water vapor to transfer in and out of the container. The exception is that hard plastic that a lot of late model fuel lines and stuff are made out of. Chevy High Performance brought this up a while back,(obvioulsly before they changed the containers) they felt bad about reccomending ford fluid, but their main basis for this was the old (metal) container and the price.

 

I've brought the subject of the plastic container up on this board before and some people thought I was nuts.

Baer also recommends only buying fluid that comes in a metal container since the plastic most bottles are made of will allow moisture in over time.

 

The technical term used is water vapor transmission thru the material. Most containers are made of some form of (PE) Polyethelene useuslly HDPE. PE (thickness dependent)DEFINATELY is permabable to water vapor. However, bottles could be manufactured with multiple layers, One of which is sandwitched inbetween the other layers that is not succeptable to WVT. However, Cost per container becomes a factor.

 

How do you get the fluid from the contaner to the master cylinder without exposing it to the atmosphere? Also most master cylinder covers are plastic with a vent hole. Good info to know tough but I think that there is such a small benifit from a metal can that it is like brushing your teeth before a race to save weight.

 

the plastic of the master cyl resorver doesnt let much water thru.

there is a seal and a diaphram to keep air out, even when the displacement inside the system changes.



the fluid does draw water out of the air, but its not instant.... so while you shouldnt leave it exposed for a long peroid of time, taking the cover off to check it and change/fill it isnt a issue....




and the system does let a lil in.... thats why you SHOULD change the brake fluid every 2 years or so... i usually do it whenever i bleed my brakes since it isnt really any more work when you have speedbleeders...

 

Well, I know that the metal container thing was a big enough deal to the military that they changed the specifications of brake fluid containers from plastic to metal. All the fluid we get at the shop is in 1/2 gallon metal containers now, and when they made the change they even told us to dispose of the fluid in plastic containers no matter how new it was.

 

The Ford Heavy Duty stuff made a big difference, i used to use what was on sale until i started working at a Ford dealership.