TonyC

kinda lost here...

clutch went out, replaced the slave clutch cyl (NIB, China made??? from Napa) over a month ago. bleed almost 1 full bottle of brake fluid thru (using both mityvac and foot pumpin'). clutch went back to normal. 2 wks later, the clutch fluid looks all gray w/ bits of metal. i drain/refill but didn't re-bleed. 3 wks later (yesterday), the clutch is feelin' kinda funky and i peep in to see the clutch fluid totally black w/ metallic sheen again.

brake fluid is Ford HP DOT 3. fresh bottle.

i searched both Mnet and here and found similar, but not exactly the same probs. one long discussion on clutch cyls here: http://forum.miata.net/vb/showthread...aster+cylinder

is it time to replace the MC?

cjernigan

iTrader: (13)

Sounds like you could use at the minimum a MC rebuild and cleaning. You might of just had a bunch of crap in there. A rebuild kit is like $12-15 so you could clean it up, replace the internals and then rebleed the system and see what happens.

rollin904

iTrader: (5)

yea i just flushed mine when i replaced my slave and it's already blackish again..****** gay, i might do my master cylinder if it gets worse

miatamania

iTrader: (9)

I replaced both master and slave...**** is still black, any ideas on that one?

Joe Perez

iTrader: (8)

My clutch fluid is generally pitch-black as well. When I rebuild my M/C and S/C a year or two ago, I determined that the rubber seal between the plastic reservoir and the M/C body was shedding a fine black powder. The seal was not hardened or cracked and was still doing a good job of sealing, it was just letting loose this black stuff.

Not having a replacement handy and needing the car back in service I simply cleaned it as best I could, then reassembled. Within a few weeks the fluid returned to its normal black color, however the performance of the system does not seem to have been degraded.

I'd simply chalk this one up in the column of "irritating, but not critical."

devin mac

iTrader: (2)

mine's more or less pure black as well and functions fine, if that's any consolation.

TonyC

good to see this isn't just me. however, i have a feeling my MC is failing... local parts store quoted me $40 for another NIB from China. picking it up t'row.

xturner

I think it's time to do the MC. I replaced my slave in December, bled it all out with fresh fluid, and it went gray on me within a month. Then last week the MC just failed(sweet - in heavy traffic going home).

FWIW, I just bought a new Mazda MC for $95. It took about 25 minutes to change over, another 10 minutes to bleed. Probably the easiest repair I've done in 10 years.

I'm at a loss to explain why it would turn black after replacing both, unless the new MC was defective. As I understand it, the fluid changes color because it picks up rubber from deteriorating MC seals. It's very unlikely it travels all the way back up the clutch line.

Joe Perez

iTrader: (8)

Go to NAPA and buy a rebuild kit. Seriously. Cost should be about $10, and it's dead easy to do. Getting the M/C in and out is the hard part, rebuilding it is a piece of cake.

miatamania

iTrader: (9)

Good to know...I've got so much **** in that category it gets annoying.

TonyC

Joe,

i've read your take on rebuild kits... Napa here wants $15 for 3 fuggin o-rings. it'd take me an extra hour to rebuild it to something resembling working condition.

i'd just rather spend the $25 for that extra bit of piece of mind (and a new coat of paint on the MC).