snarlingbeast

So I'm planning to flush my entire brake / clutch system soon because a) it's about that time and b) there's air in the system from a botched bleed job (fluid in the MC got too low). As a result, my clutch isn't fully disengaging.

After reading several threads, it sounds like it's challenging to get air out of the clutch system. So I had a thought: you would normally bleed the clutch by opening the clutch slave bleeder and pressing on the clutch repeatedly. But since the brake and clutch are both in the same fluid system, shouldn't you also be able to open the clutch slave bleeder and bleed the clutch by pressing the brakes? I'm thinking that may help clear the system more completely (alternating pressing the clutch pedal and the brake pedal).

Am I wrong? Could that possibly screw up the whole process? Or have I stumbled upon a brilliant new bleeding method?

Jon316G

iTrader: (1)

The brake fluid reservoir is divided between the two hydraulic systems.
The clutch side has a hose that routes to the master clutch cylinder.
If you only bleed the master brake cylinder, you wouldn't bleed the clutch system from the master clutch cylinder down to the slave cylinder.
So you need to also bleed the slave cylinder to ensure all the air is out of the system.

Its not easy to reach, but lay on top of the engine and reach down to it.
Its basically behind the oil filter.
I've done it from underneath too, but it wasn't any easier.

Below is a pic that might help visualize it better.
The connection labeled 'B' is where the hose connects that runs to the master clutch cylinder.
You can see the bleed screw for the brakes at the front of the master brake cylinder.
As you can tell, by bleeding this screw, you won't be bleeding the clutch.

snarlingbeast

Yes, correct. But what I was describing was opening the clutch bleeder and pushing on the brake pedal, instead of just the clutch pedal, to enhance the bleeding of the clutch system since it shares fluid with the brake system. Do you think this would do anything?

dannobre

iTrader: (3)

No...they have separate master cylinders...all the clutch does is share the reservoir with the brake fluid

TeamRX8

iTrader: (25)

For the clutch slave bleed take a long piece of small tubing and run it back up into the master reservoir and secure it there with a piece of duct tape etc. Open the clutch bleed screw with a 10mm brake line wrench. Go into the driver side interior and using your hand manually push the clutch pedal down, wait a few seconds, then pull it back up. Repeat this process a dozen times, then tighten down the bleeder screw and check the clutch pedal to see if the air is out. Repeat again if necessary. Once completed, be sure to pinch off the bleed hose as you're removing it from the bleed screw so the fluid inside it doesn't run all over the place. You can lift it up higher than the reservoir and releasing your pinch allow that fluid to go back into the reservoir.

Alternatively you can have second person assist with doing it the down-release tight-up method. It's really pretty easy, but unlike the brakes the clutch pedal will go to floor and stay there which requires it to be pulled back up. So you need to do it by hand rather than foot.

Did a braided clutch line recently and tried to use the vacuum method and that didn't work too well. The other methods above work fin.

snarlingbeast

Good info. Thanks for your input, guys.

Targatheory

SnarlingBeast, to purge air the simplest way just keep pumping and pumping. It just takes a while.
Even with the slave cylinder bleeder open, if you try to pump the brakes to help bleed the clutch well, nothing will happen. You would get the same exact mechanical response as when you do driving, like heel toe downshifting, engine braking, panic stop/downshifing etc., and that's your brakes moving. The clutch pedal is never affected by the brakes and vice versa. Good thought, but they are two hydraulic systems that only share fluid via one reservoir.

A little tip too, if you're having a friend help you. Get your communication together well enough so that as the pedal is reaching the floor, right before the complete stop, close the slave bleed screw is shut first. So you and your buddy should signal each other at just the right moments so that one way pressure is still being exerted through the slave as it is being closed, hopefully minimizing any chances of tini amounts of air somehow being sucked in.
Good luck.

TeamRX8

iTrader: (25)

Made a bonehead move last night which resulted in me getting air in the clutch line. Allowed me to test a 1person clutch flush method and it worked well. Since the clutch pedal stays down I theorized that this would allow 1 person to flush the clutch using the 2 person procedure:

Attach hose to clutch slave bleed nipple.

Open bleed nipple using 8mm brake wrench.

Push clutch pedal floor

Close bleed nipple

Pull clutch pedal up

Repeat this back and forth procedure as necessary. If there is a lot of air on the system you won't feel much more than the spring pressure pushing the clutch pedal down. As the air is worked out you will feel fluid resistance pressing the pedal down. Also, once all the air is out you still have to pump the system back up, pushing and pulling the pedal quickly a dozen or do times until it feels normal and returns on it's own.

Also, if you go to the Speedbleeder website they sell a flush fluid catch container that is a plastic bag with a clear silicone hose that is worth every cent. Not only does it prevents spills etc you can see air bubbles, discolorationclean fluid etc in the line as you bleed. Highly recommended, especially for single person flushing.

xsnipersgox

dude team.. that just sounds like a pain in the ***.

rminrx8

if i have air in my clutch system.....could this be the reason for wat has been goin on in my car???

It started like a couple days ago and everytime i shift into any gear it takes a long time to go forward. The RPMs go up but the car doesnt accelerate as fast. it delays and everytime im @ an intersection or hill i have to sumwat floor it so i can go fasterr..

WATS THE PROBLEM? i would really appreciate any suggestions

snarlingbeast

That sounds like your clutch is slipping and may need to be replaced. Air in the clutch hydraulics makes it difficult to disengage the clutch and shift gears. Your issue sounds like the opposite - your clutch is not engaging fully.

rminrx8

kk thanks bro...im actually going to get my 8 cheked out tomorrow...if it is the clutch i guess ill have no choice but to replace it