Brake line opinions
01-01-2017, 02:50 PM
#23
Did you get air in the ABS? That's the easiest way to screw up a brake job. Also, do you know the correct bleeding pattern? It's a triangular system (I pulled this from Cadillac FAQ)
* Right rear inner
* Right rear outer
* Left front inner
* Left front outer
* Left rear inner
* Left rear outer
* Right front inner
* Right front outer
* Right rear inner
* Right rear outer
* Left front inner
* Left front outer
* Left rear inner
* Left rear outer
* Right front inner
* Right front outer
If you're bleeding manually, the above procedure is fine but when you're bleeding the system with a Tech 2, you should run through the program twice--once using the inner bleeder valves, and once using the outer valves. It doesn't give you the option to repeat individual steps or reverse the bleeding sequence.
Inner first vs. outer first is constantly debated but I agree doing inner first. It's best to get air bubbles trapped on the inside of the caliper out (and replace that air volume with fluid) before you finish the job using the outer valves.
01-01-2017, 02:54 PM
#24
The only thing that Motive Power Bleeders do is keep the reservoir filled. They can't generate enough flow to force entrapped air out of the system. Neither can the ABS pump motor (activated using the Tech 2), although it's much more effective than the Motive Power Bleeder.
Even with both pieces of equipment available, you still have to pump the pedal. How you pump the pedal is vital to a good bleed. Bleed using strong, smooth pedal strokes, holding the pedal for 2-5 seconds at the bottom of each stroke.
The hold time is determined by the equipment you're using. If the ABS module is pumping, bubbles are evacuated much faster. Therefore, you don't have to hold the pedal down long. If you release the pedal too quickly, the bubbles you just evacuated will be sucked back into the slave or local high point and trapped again. In extreme cases, I've seen it take 8-10 seconds for bubbles to travel all the way up the bleeder line from the clutch slave cylinder.
Once you think you're done, check your work with a couple of max effort pedal strokes. Down and hold for 5-10 seconds. If anything comes up, repeat until you see only clear fluid. Whatever you do, don't use these violent / max effort strokes in the beginning when there's a lot of air in the system. That's because the turbulence will aerate air pockets and make your job infinitely harder. These final efforts are only good for eradicating the last 1% of air in the nooks and crannies of the hydraulic system.
Even with both pieces of equipment available, you still have to pump the pedal. How you pump the pedal is vital to a good bleed. Bleed using strong, smooth pedal strokes, holding the pedal for 2-5 seconds at the bottom of each stroke.
The hold time is determined by the equipment you're using. If the ABS module is pumping, bubbles are evacuated much faster. Therefore, you don't have to hold the pedal down long. If you release the pedal too quickly, the bubbles you just evacuated will be sucked back into the slave or local high point and trapped again. In extreme cases, I've seen it take 8-10 seconds for bubbles to travel all the way up the bleeder line from the clutch slave cylinder.
Once you think you're done, check your work with a couple of max effort pedal strokes. Down and hold for 5-10 seconds. If anything comes up, repeat until you see only clear fluid. Whatever you do, don't use these violent / max effort strokes in the beginning when there's a lot of air in the system. That's because the turbulence will aerate air pockets and make your job infinitely harder. These final efforts are only good for eradicating the last 1% of air in the nooks and crannies of the hydraulic system.
Last edited by FuzzyLog1c; 01-01-2017 at 03:11 PM.
01-01-2017, 10:34 PM
#26
Compared to that, pressure and vacuum bleeders amount to nothing.
01-01-2017, 11:45 PM
#28
The reservoir doesn't see that pressure. The pressure happens downstream of the piston in the master cylinder.
01-02-2017, 07:39 PM
#30
Hay fuzzy, the former set up that I had with the brembos had a smaller master (it was a swap) dose the booster on the v have that much *** you can run the pedal all the way to the stop ? It has a good bit of resistance I just feel like there should be more.
01-02-2017, 09:53 PM
#31
I can't press my pedal all the way to the stop, if that's what you're asking.