Brake fluid Shell Vs Castol SRF

Time to change my brake fluid. Last changed 3 years ago.

Anyone compared Castrol SRF with OEM dot 4 Shell?

Castrol is supposed to resist water better than other fluids so it doesn't need frequent replacement. And it has a higher "wet" boiling point so for street use seems better too.

A bit expensive at $ 70 per liter. How many liters does a 360 brake system use?

 

1.7 litres capacity so minimum of 2 litres required for full flush.

I use SRF as standard Dot4 was not up to track day use.

That said, I never had a problem with standard stuff on the road and there's absolutely no need to use the very expensive SRF unless you are going to put the brakes under extreme conditions like track use.

In my opinion you will gain absolutely no advantage using SRF as opposed to using standard Dot4 and replacing every 24 months or so.

 

I've always used Ate super blue racing fluid, DOT4. It costs about $18.00/L and it comes in clear and blue. One can alternate blue and clear at changes to determine when the old fluid has been evacuated. It is a German product that can be found at foreign auto parts
stores.

 

ATE is great brake fluid. The only reason I want to try the Castrol SRF is that is resists water contamination better (lasts longer before it needs to be changed) and has the higher wet boiling point as well.

Oh, so has anyone changed their brake fluid?

Is there any special procedure with the ABS system or will the regular two person technique do the job?

I see there are two bleeder valves on each caliper-one on the outside and a second one the inside. I assume both need to be bled, but one at a time.

 

I flush my system by myself using a motive bleeder. Just fill up the motive canister with new and aproved fluid at 12psi. Start with the farest wheel and start to open all the caliper screws until new liquid start coming out. Same process on each wheel. Very important to be sure that the motive doesn't ran out of fluid.

 

SRF does indeed have a significantly higher wet boiling point (circa 25% higher than others) but it's replacement cycle is still recommended at only 18 months which is no longer than any other DOT4 fluid. Really you're probably wasting money on SRF unless you're putting the brakes under the kind of pressure that can only be dished out on track.

In order to bleed the brakes properly and fully one needs to use the SD2 machine to allow the servos/pumps in the ABS system to open and close during the bleeding process. Failure to use the SD2 means that the fluid contained within the ABS system is not flushed through.

 

Thanks for the info. I will let the dealer do my brake fluid change so the fluid in the ABS will be changed too.

 

Not quite true. As long you dont empty the fluid canister you dont need the SD2. You are just replacing the old fluid with a new one. Only a very small part of the old fluid will stay but it is insignificant.

 

MG- Unless you are tracking your car, very expensive brake fluid is a waste of money. If it is for street use, the biggest problem for brake fluid is moisture absorption. Castrol LMA (low moisture avidity) brake fluid is ~$9 per quart and is recommended by my technicians because you never get the pockets of water in your system that can lead to corrosion. Both dry and wet boiling points are high enough for any street use.

http://www.castrol.com/castrol/sectiongenericarticle.do?categoryId=9012213&contentId=7024043

Taz
Terry Phillips

 

DOT thru actual measurements has figured brake fluid absorbs about 3% water in a 12 month period while in use. That is what the wet boiling point spec is based on. It is not to say SRF absorbs it any more slowly, only that when it does its degradition is X. I am sure there are differences in absorbtion rates but it still has water and that water can still rust brake components no matter the boiling point.

SRF is a great product but its use would not make me change it at any different intervals.

 

I run SRF in my race car, but the conditions the brakes are subject to are much higher than you would ever see on the street. Unless you are actively racing, not even DE, your are fine with Super Blue or another "premium" brake fluid for around $10/litre. You are better off flushing the system every year with the regular fluid than trying to go years with SRF. The pedal will feel firmer with fresh fluid than two year old SRF. Also understand, I flush the SRF every race weekend.