ajbarnes1

*2005 350Z Base*
3 weeks ago I replaced my rotors, pads, and lines with EBC/Redstuff/Russel SS. As such, nearly all of the brake fluid was drained from the system. After reassembly, the pedal took two presses to get the brakes to truly engage, and was hardly confidence inspiring. I read up on all the nooks and crannies that air can get in and the general consensus on 350Z brake bleeding and proceeded to bleed it two or three more times. Last week I got the Motive Power Bleeder, bled in the prescribed order (RR/FL/RL/FR) and in the prescribed manner.

The pedal feels 10 times better than it did after the first few bleeds, but it still takes two half-pumps to get the pedal rock hard.

Do you think I need to give it another go with the power bleeder, or could it be something else (MC, booster, vacuum line)?

No fluid leaks; used DOT 3 fluid; when the brakes grip on the second half-pump, it feels great - grinds to a stop (figuratively speaking).

Thanks for the help!

mcarther101

iTrader: (8)

If it were me, I would go buy a gallon of shitty inexpensive brake fluid, flush the system, then replace it with race fluid. Then you'll know if it's air in the lines or not at least. If not, possibly brake booster? I'm at 110k miles on OEM master cyllinder and brake booster though; haven't heard of these being problematic in our cars yet at least.

I know is if caliper is poorly designed, and the bleeder valve isn't positioned at the 12 oclock position, air can be trapped inside the caliper itself. I doubt it's poor caliper design though.

thekinn

iTrader: (18)

Does this mean that you drained the system dry of fluid? ie. no fluid in your reservoir at one point?

ajbarnes1

All 4 calipers were simultaneously disconnected from the system while the soft lines were replaced. Most of the fluid was drained out -- whatever came out via gravity. Truthfully, I didn't think to monitor the fluid level since it was all just pouring out anyways.
I was under the impression that the power bleeder was a sufficient alternative to bench bleeding -- if that's what you're getting at.

Thanks.

omgitsweasel

did you pump the brakes without fluid in the system at all? it only takes one dry pump to start to degrade the seals in the MC.

ajbarnes1

That's a distinct possibility.
Thanks.

ajbarnes1

At this point I'll just replace the MC and be done with it, but I'm curious as to why the MC can still build up pressure with bad seals on subsequent pedal pushes? Does this mean that only one axle is providing brake force?

omgitsweasel

depends on how bad the seals are. heat expands things and could be just enough heat to expand the seals. you really wont know unless you take it apart.

so yea, just get a new one. they arent that expensive.