taffin

Did a track night at Yas Marina on Thursday night.

In the third session, I was getting pulsing on the rear brakes into two corners after a high speed section and on the third time round the pedal went soft. I don't think fluid had been properly bled in a while. I have racing fluid which is 12 months old in the car.

Next track day, I must switch TC off and take a bravery pill

But a question, now that I have obviously boiled the fluid, does it need to be drained and new fluid put in or does it just need a bleed now?

NorthVan

Do a complete fluid change, and if you track do it more often then once a year. It is cheap insurance to change it regularly.

kyrocks

Needs a proper brake bleed. I recommend Castrol SRF or Prospeed 683 brake fluid for your conditions. 12 months is a VERY LONG time to not have your brake fluid flushed if you track your car, especially in hot conditions. Depending on how often you track, I recommend you bleed your brake fluid every 3 months (6 months max). There are others who bleed it after every track weekend as well.

taffin

thanks, will change it out next weekend.

is bleeding something I could accomplish on my own? my mechanical ability is somewhat limited.

kyrocks

It can definitely be done on your own, but it helps to have a Motive brake bleeder. If you have never done it before, I would strongly recommend someone to show you how to do it first. It is not hard, but very important you do it correctly.

Product:
http://www.motiveproducts.com/

How to generally bleed brakes:
http://www.pelicanparts.com/techarti...eed_brakes.htm

taffin

I will see how much local specialist charges for a bleed when they change the fluid, it may just be a case of pay the money for peace of mind and not hassling with the admin of it all.

I will probably bring one of those kits of Amazon anyhow.

taffin

do wheels have to come off to bleed? got standard GT3 rims on my car.

If so, then definitely not worth the admin of doing it myself.

NorthVan

Wheels off is easier.

NorthVan

I bought the Mityvac with the brake fluid flush attachment.


I haven't used it yet, but could be an alternative to the Motiv (which I have as well). Mityvac can do a bunch of other things as well.

Izzone

I have this for trans fluid

I need to see the brake flush attachment, I will but now

ChrisF

Haven't done it yet on the GT3, but on the Cayman S with the Motiv, the bleeds were pretty easy. +1 on more frequent changes. I do about every 2-3 track events.

Alan C.

If you use a Motiv be sure that you keep track of how much fluid is in the brake reservoir. If not you may introduce air into the system and it will then be a pain to get it out. Some people put fluid into the Motive tank and some just fill the brake reservoir to the top and pressurize with the Motiv.

Something that I found useful is to use a turkey baster to extract the current fluid in the brake reservoir to the minimum fluid level mark on the reservoir and discard it. I then extract the remainder into the bottle I use for catching the fluid when I flush. Once that fluid is in the bottle I draw a line around the fluid level. I then fill the brake reservoir to the top and attach the Motiv empty. When the drain bottle hits the marked line I stop and refill the brake reservoir. It should be nearly impossible to ever introduce air into your system following this procedure. When you stop there will be the amount of fluid from the min line to the top of the reservoir in the brake reservoir.

Sorry if this is a bit wordy.

lowside67

Although it seems a bit counter-intuitive, if you use a brake fluid that is "superior" to OEM such as Motul RBF600, you will actually have to bleed your brakes MORE often than with OEM fluid, whether you are tracking the car or not. The reason for this is because high performance brake fluids tend to be substantially more hydroscopic than stock, i.e. they absorb moisture much more easily. As you can naturally imagine, a brake fluid system that had some water content would boil much quicker than one without, which is likely why you boiled your brake fluid so quickly at your track day.

Different people have different maintenance schedules but when I ran RBF600 in my race car, I flushed my brake system every 3 events or 6 months, whichever came first.

Hope that helps,
Mark

NorthVan

I bought the brake fluid attachment for my wife's car, Motiv can't figure out how to make an attachment or her make (Acura).

taffin

just got a quote from the local race shop.

they quoted me on PRF660, which form a quick web search reveals it as AP Racing which makes sense as they sell AP stuff.

Is it ok to use this? I have read certain fluid damage the seals on the GT3??