Brake Fluid Help...

[benm]

Hi,

(1995 R33 GTS-T S1)

I went to a track day today expecting to have really strong brakes (brand new DBA Clubspec Rotors and 5mth old Bendix Ultimate pads). After only 3x 7 Lap sessions my foot went flat to the floor and after asking people what the problem might be they all suggested that I had cooked the brake fluid (pedal slowwwwly came back after leaving the car rest for 2hrs before driving home but still nowhere near before I went to the trackday).

Now the questions I have are:

1) What is a good quality brake fluid that is going to give me no problems at all on a trackday? (5x 7 lap sessions with a 50min gap inbetween each session). So far I have been recommended:

Motul DOT 5.1 = 270c

Castrol SRF = 300c

Are these compatiable with my car?

2) On the lid of the brake fluid container it says "only use DOT 3 brake fluid), but I can't find any when doing a search on the net. Is this because in 1995 (when my car was built) DOT3 was all that was available back then and technology has increased since?

3) How much fluid is required to do a complete change over from the old fluid to the new fluid?

4) Approx what is brake fluid worth ?

I want to get something really good because while having a speed limiter is annoying it certainly isn't dangerous, but having no brakes at all when braking from 160km/h -> 60km/h its not a pretty situation.

Thanks,

Ben.

[Brody]

Ok,

To answer a few of your questions,

The 2 recommendations made are good fluids, you'll need abit over 1L to do a complete flush so ive been told. To do this, Clean the current crud out of the container, and top it up with the good stuff. You should start by flushing the longest line upto the shortest. This usually goes from back left, back right, front left, front right, after each, check container and topup.

Something that may help the bleeding process, http://www.speedbleeder.com . These can be sourced locally from the a.c.t, ill post the info tomorrow if you want as it's at work.

You may also want to invest into better pads for the track, no doubt the current 1s would have heated up and been kinda useles. Ferdo 2500/3000 are great for track, 2000 are more street. You may be able to get away with the 2500 for street without 2 much noise.

Steel braided lines will also help alot as they will not flex at all and do not absord any moisture.

I think the motul fluid goes for $50, for 1/2 L.

Since its all interlinked, youd want to flush your clutch line as well.

99% of the stuff out there is compatable, but 1 ive seen is the AP600 which warns not to use in conjunction with ure clutch as it containes certain chems. that cause a gas reaction.

hows the new rotors feel?!?!?

[Roy]

Hope you enjoyed the day... i have found the AP 5.1 that i run serves me well. No fade and real strong pedal even at the end of session.

From memory its about $60 for a bottle (500ml???, worth the money as you dont really use a lot of the stuff) .

Whatever fluid you end up running i recommend you flush all the old fluid out and replace with new, dont just bleed and top up the fluid

I also run RB74 pads, pretty dusty but are quiet, not too aggressive on rotors and pedal is firm all day. (R32 so car may be a bit lighter and kinder to brakes)

Greg from Race Brakes in Wetherill Park had done all my brake work, and has helped me come up with an economical brake upgrade that handles 20 minutes of abuse with D01J tyres without a hint of fade. Cant give him a big enough rap!!!

[Silver-Arrowz]

Yeah racebrakes is where I get my stuff from. RB74's are great but I'm in love with the comp 9's. They use to recommend ap 5.1 but now recommend caltex. Go there and ask him. It's 30 bucks a bottle and just as good as the ap 5.1

[Guest Boxhead]

well i love my brakes after i have cleaned the old crap outta the lines, i found i have braided lines i put in the top of the line motul stuff, im not sure were you guys are buying your stuff, but i think i paid like $26 a bottle, i think 1 l per bottle, its motuls racing fluid, its rated higher then dot 5.1...

maybe give that a go, i got it at autobarn.

[Roy]

Im sticking with the AP 5.1, the Caltex stuff could be every bit as good, but im on a good thing and the extra expense of the AP doesnt really bother me, it s not like i use 5L every month like engine oil. It may equate to an extra $30 a year???

[Nismo_286]

Hi,

I saw your recommendation on Speed Bleeder.

Have you tried using this system? Is there a size that meant for Skylines?

Cheers.

Ok,

To answer a few of your questions,

The 2 recommendations made are good fluids, you'll need abit over 1L to do a complete flush so ive been told. To do this, Clean the current crud out of the container, and top it up with the good stuff. You should start by flushing the longest line upto the shortest. This usually goes from back left, back right, front left, front right, after each, check container and topup.

Something that may help the bleeding process, http://www.speedbleeder.com . These can be sourced locally from the a.c.t, ill post the info tomorrow if you want as it's at work.

You may also want to invest into better pads for the track, no doubt the current 1s would have heated up and been kinda useles. Ferdo 2500/3000 are great for track, 2000 are more street. You may be able to get away with the 2500 for street without 2 much noise.

Steel braided lines will also help alot as they will not flex at all and do not absord any moisture.

I think the motul fluid goes for $50, for 1/2 L.

Since its all interlinked, youd want to flush your clutch line as well.

99% of the stuff out there is compatable, but 1 ive seen is the AP600 which warns not to use in conjunction with ure clutch as it containes certain chems. that cause a gas reaction.  

hows the new rotors feel?!?!?

[red17]

I use stuff i buy from Motorbike stores. Usually a Silkolene or Belray. Its all brake fluid, its just bike shops seem to sell more performance fluids than your average Autobarn.

Top of the line Silkolene would set you back about $38 for 500ml's and I can say is very good indeed.

What I tend to do when bleeding is buy some cheap 8 dollar mobil for flushing out the old, and then put the good Silkolene in. Luckily theyre different colours so it makes it easy to know when the new fluid is in the system.

[knore]

I think someone needs to do a

"HOW TO BLEED YOUR BRAKES ETC" Thread in the DIY section

Anyone?

[Brody]

Didint end up using the bleeders becuase im not intending to have track days etc.

Though from everything I read up on them, they seemed great.

[blind_elk]

You don't really need to go to the expense of those synthetic fluids. Nulon have a standard, glycol-based one that works fairly well. I think it's a DOT4. And it's only about $10 for 500ml.

The important thing to avoid the kind of problems you had is to change the fluid annually. The fluid is hygroscopic (absorbs water), and that's what causes the fade. Fresh brake fluid will normally remove the fade caused by boiling the water in the fluid.

[red17]

Well I can sure tell the difference between 8 dollar mobil and 30 dollar Silkolene and thats just on the street.

Now if hes using his car at the track he needs a fluid that has a very high boiling point. Cheap fluid simply doesnt have a high enough boiling point, well suited for occasional hard braking on the street, but 1 hard lap around a track and its ready to give up.

Having used many different fluids in my old pulsar which was a regular track attendee, I was amazed at the difference in performance between fluids. I did a change before each track day to ensure the best performance on the day.