Mike J

I think its the nature of the rubber hose to the slave - its likely picking up color and perhaps material from the inside of the hose. I have bled lots of these cars, the initial bleed always comes out black.

Cheers,

Mike

IXLR8

On a brake master cylinder, I'd agree, but a clutch master cylinder gets a full stroke all the time

Mike J

woops - reading too my posts - my bad. Of course.

eddie_993

Hi again guys, sorry to restart a dormant thread but need some input/help again.

I replaced the clutch slave and bled the system last week. Have driven the car about 80 miles since then. From the moment it was replaced it has been smooth but the pedal engages very low. I read on one of the threads here that you have to drive the car a lot and then re-bleed it after a week or so. I won't have time to bleed it again this weekend but maybe next weekend, if not, then the one after.

Anybody experience the pedal catching low also? What was weird was that when I was bleeding the system, the reservoir fluid level would not go down past the mid-level. I would fill it up to the brink, pressurize the motive bleeder and then when my friend would open the nipple, fluid would go down to the mid level (right around where it says PP or something like that). If we left the nipple open for a few seconds more the pressure in the bleeder would go down but not the fluid level.

Confusing to me

Mike J

When you were bleeding, any air bubbles in the hose coming from the bleed nipple?

How low is low? Lower 1/3, middle, upper? Is it the same everytime?

Cheers

Mike

eddie_993

Hi Mike,

Yes the air bubbles would come out while the fluid level was going down and then it would start coming out clear. When it would get to the mid level of the reservoir, it would start sputtering a bit at the nipple and then I believe it would stop and nothing would come out. After that would happen or during it the air pressure would go down, fluid would stay the same.

Definitely lower 1/3 and fairly consistent. It seems a bit better after a few minutes but that might just be me getting used to it.

eddie_993

I forgot to mention that I bled the system before changing the clutch slave because I didn't think I would have enough time to change it that weekend. Ended up replacing it the next day. Both times when I bled the system (before replacing the slave and after) it did the same thing, that air sputtering.

Mike J

I suspect you are letting the fluid level get too low at the reservoir - the point that the clutch circuit sucks air is well above the mid-point, its quite high. I use a simple method, I have a custom reservoir cap that I can connect to my compressed air, I put about 10psi on with the reservoir full, and then bleed the clutch a bit, perhaps taking down the level in the reservoir a 1/4" or less, I then top it up to full, and do it gain until I get clear fluid - you should not at any time see bubbles, the means either the circuit had air or you are introducing it.

Cheers,

Mike

eddie_993

Hmm interesting, I assumed that as long as the fluid level is above the minimum level or visible in the reservoir then it's ok. Next time I'll only let it drop a bit then re-pressurize.

If there is air in the system then bubbles will come out(right?) but I am assuming you mean that it should not sputter, that is when I am introducing air.

If you ever come down to LA Mike, a couple of beers on me

Best,
Eddie

Mike J

Exactly - air bubbles and sputtering means you are introducing air, or you have a major fault in the system (which is less likely).

gtroth

Yeah, if you are introducing air at the top of the system it might take a minute to see it at the bleeder nipple. If it were me, I'd bleed out the newly introduced air, close the nipple, active the clutch pedal a few times and bleed some more, and then bang on the clutch pedal with my fist while bleeding to shock loose any bubbles that might hang up in the master.

You might also try running the motive 'wet' (pour your whole can of fluid in it) so that you can't force air into the system. Plus then you don't have to pay close attention, disconnect, add fluid, reconnect, and repressurize when the reservoir gets low.

eddie_993

I still have at least a week till I do this but I might try out the "wet" tactic. If I don't do that I guess I will only let the fluid level go down to about 75% instead of 50%. Just a hassle having to repump that thing every time.

Anybody have any idea how much fluid is in the clutch lines? If I remember correctly the brake lines have about 1 liter??

Thanks for your input and enjoy your Sunday night!

kjr914

VERY IMPT:
The clutch slave fluid is ONLY pulled from the back (toward rear of car) of the brake fluid reservoir (about the back 1/5 of the length of the side. It is hard to see unless you stare at it for a while, and ATE Blue fluid might help too... There is a separate "wall" inside the reservoir that, once the level drops just a little bit, brake and clutch circuits effectively have different reservoirs due to the separating wall.

You are draining the clutch section dry, but the reservoir looks full because fluid for the clutch isn't coming from the main part of the brake fluid reservoir. Since the clutch section is really small, it drains quickly... Fill often, best to use a friend to pump the clutch and fill the tank while you bleed from under the car.

osugasman

Anyone use a MityVac and suck the fluid through versus pushing it through with the Motiv Power Bleeder? (I don't have a Motiv nor a helper today and want to get this done while the lift is up and running--helped a buddy out with his 97 993TT earlier but he's long gone.)

--Brian

CarreraX

Brian,
Are you doing brakes or clutch? I can possibly come down there late tonight if necessary. Are you going to the Taj thing for John Dixon tomorrow? Mark