So before every track day I like to bleed or flush my brake fluid depending on how much abuse it took.

after my last track weekend my pedal was still FIRM I loved it, but I just had to screw with it...I decided to just run a bottle of rbf600 through the system to be on the safe side.

well...we did that and now my pedal is mushy.

So heres my thing, for some reason every brake bleed we do on my car seems to be hit or miss, some times its GREAT and some times it sucks. there has to be something going on.


any idea's?

I do the proper brake bleed order


and some times we bleed each screw an excessive amount (3 bottles through the system)

One thing I'm suspecting is that your not suppose to turn the ignition on accessory (we had to do this to move steering wheel that was locked) maybe the abs pump trying to prime screws things up?


Basically I'm looking for all the little things that might screw up a brake bleed that you guys have noticed.


tia


*edit

no the Reservoir never runs dry, we actually have a 3 man team..the extra man is filling the reservoir at all times

 

Honestly, I think you have a good observation. I've experienced similar inconsistency in my pedal after bleeding with MOTUL RBF600.

We recently acquired a Motive Bleeder, and two cars we bled came out perfect. I think there is something inherent in the "Pump, pump, pump, HOLD" process that is inconsistent.

 

I've been using the motive bleeder with rbf 600 for a couple years now and never had any of the issues you speak of. I bleed the old-school method/order of furthest caliper from the master cylinder first and work my way forward starting with the outside nipple and moving in. I don't use the diagram you posted above. not sure but maybe the KEY-ON thing was your problem... I've never had to do that.

the motive power bleeder is great. makes flushing the whole system cake.

 

3 bottles through the system? Yikes! Use the Motiv bleeder to remove process inconsistencies and if you still have a problem try Motul 5.1 which is less hygroscopic and plenty boil resistant.

 

I use my blue point power bleeder. Never had any issues. If ur ever in my area or come to another track event I can bring it and let you use it.

 

just use the foot and someone to crack the bleeder screw

 

bump for more info

 

I know that the shop manual says, but if the system is wet and no air, I don't see how it matters which wheel you do first.

 

thickness of your brake pad and type of brake pad material will affect how mushy pedal is regardless of bleeding correctly. Some brake pads are more compressible than others. Ask me how i know. I had low brake pad material and bled the brakes. Still was mushy. This was on Hawk DTC-70. Compared to brand new Hawk DTC-70, it was night and day difference with same exact brake bleeding procedure with the only variable being pad thickness.

 

^
yea I have definatly noticed that too, however in this case before the bleed the pedal was firmer then after ....nothing was touched other then bleeding the brakes.

 

You need the vdm spec brake bleed, I always has a firm brake pedal.

 

This is probably being silly to the extreme but maybe someone doesn't know.....as your assistant strokes the brake pedal they must hold it down at the end of the stroke without exception and the person at the caliper must close the bleeder as soon as flow stops. Otherwise, you chance the introduction of air. So, provide careful instruction before you start.

 

At the rate you're going through RBF600, why not switch to Castrol SRF. Needs an annual flush at the most, and just needs to be bled the rest of the time. I used to run RBF600 and I won't be going back...

l8r)

 

^
what kind of temps does it handle?

 

I have always bled the evo while it is RUNNING, keeps the ABS module working and pushing fluid through it while on. I too have/use the Motive bleeder, I flush it each year, with ATE super blue/gold, and have ran track days and about 25+ autoX events each year... no problems with this process.