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View Full Version : pedal on floor, how to bleed the clutch?



JK35
07-25-2010, 01:02 PM
I just installed a new clutch from Southbend, and a steel flywheel. The previous SB was a segmented ceramic/cryo'd stage V dxd setup on an AWE Aluminum LWFW, and it just wasn't suitable for the 4 stages of nitrous I am about to apply on top of over 500 AWHP from the turbo / motor itself. The new clutch is purpose built by Andy at Southbend, and uses a graphite impregnated ceramic puck disc and a hand built pressure plate above and beyond the previous one and built for truly enormous torque and HP, but this is all irrelevant, because I can't get ANY pedal to even begin to bleed the system. nothing... pedal flops to the floor or back up, but there's NO pressure in the hydraulic system at all! and again it worked fine before I disassembled and removed the clutch!

As I've done before, I installed the flywheel and clutch, snapped the new metal throwout bearing into place and installed the trans. Inserted the clutch line and it's clip into the slave, buttoned everything else up, and got my son to press the clutch pedal in while I attempted to crack the bleed valve.

But I got nothing.

I tried a power bleeder connected to the master cylinder/ clutch pedal still held to the floor by it's own spring, still nothing,
Next I tried my Robinair vacuum pump on the bleeder valve, STILL no fluid at all
I tried both pushing 25-30psi from the res. and pulling 1 bar of vacuum on the bleeder, -you guessed it, nothing.

so I began to move the clutch pedal in and out while pushing and pulling on the system, thinking that my fluid will dump out any second, after all this is a lot of pressure to be forcing upon the fluid, and it should come on out now, but it didn't


so I stopped and disconnected the line from the slave, and used silicone hose to connect it to the vacuum pump
(this is an AC system vacuum pump that will boil water at room temp, and I am using a collector trap that has a transparent bottle so I can see what's coming out)
I try the same things on just the line. I push and pull pressure on the system, move the limp clutch pedal in and out, but get nothing. the reservoir stays filled to the brim!


What am I doing wrong, not doing or what could be the problem? There was nothing wrong with the hydraulic system when I took the clutch out 2-3 weeks ago. and I just can't understand how it would resist such 'persuasion' and not dump the reservoir into my collection tank with all the pressure applied...
I'm tired, frustrated and embarrassed that I've been beat-up by a hydraulic clutch system[:o] -But I truly need some help.

what shall I do?

thanks,
-Kyle

Seerlah
07-25-2010, 02:00 PM
I would suggest a Motive power bleeder on the resevoir tank, keep the pedal in the upper position, and do it that way. Unless that is what you meant when you said you placed a power bleeder on the master cylinder. Then I am kind of stumped. No expert, but that's my advice[:/].

walky_talky20
07-25-2010, 02:33 PM
Completely limp clutch pedal is expected. Usually you just pump it 5 or ten times (you will have to pull it back up to the top obviously), then crack the bleeder while holding it at the bottom on last pump. Close the bleeder, then repeat. I'd recommend slow pumps without rapid succession so as not to unnecessarily aerate the fluid. Usually after repeating 2 or 3 times you'll have pedal pressure again. That is my suggestion. I've never needed to use a power bleeder tool, but they are handy when you don't have a helper.

JK35
07-25-2010, 03:30 PM
I've tried this with power bleeding, but I am going to work the pedal slowly and try what you said... pump the pedal slowly, hold it down crack the valve, then close the valve and try again... lemme go out right now and try that.


the power bleeding ain't doing jackschitt! not on the reservoir, and not even on the valve with the vacuum pump -like I said, I even tried both!



maybe the oldfashioned manual method will get me some pressure.

back in a few after I go out and try it...
thanks
-Kyle

JK35
07-25-2010, 03:33 PM
hey, quick question! do you do this manual bleed procedure with the cap on or off the reservoir? -or does it matter?

Seerlah
07-25-2010, 03:42 PM
I would suggest you do it with the cap off, due to vacuum pressure. But bleeding the clutch by yourself is a PIA, that's why I suggested the power bleeder. As walky said, you need to loosen the valve, and pump the clutch pedal once then leave it engaged. While the pedal is engaged, you need to then close the valve. When the bleeder valve is closed, you can then raise the clutch pedal. Open the valve, press the clutch pedal, and close the valve while the clutch pedal is still engaged. Repeat till fluid starts to come out the bleeder valve. This is the process done when bleeding the clutch without a power bleeder, and you are supposed to do it till new fluid is visible out the tube attachedon the bleeder valve (when doing a flush). Don't forget to top off the resevoir as necessary, but I'm sure you already knew that. If this procedure isn't followed, you will suck air into the system.

JK35
07-25-2010, 04:03 PM
I have a power bleeder, a vacuum pump and a teenage son who is sitting in the driver seat right now asking me if I'm almost done typing!
I've tried bleeding like you bleed brakes: pump & hold, crack the valve-close the valve, release the pedal... repeat... repeat repeat.

this isn't what your directions are though.
let metry it your way
but I'll tell you again, I have a totally LIMP pedal, there's no pressure to it at all, -can't feel ANYTHING, and NO fluid is coming out thebleed valve.

I guess I dont understand how this works!

but I'll follow your directions word for word...
be right back...

JK35
07-25-2010, 04:13 PM
that doesn't work at all, he brings the pedal up, I open the bleeder and it sucks air in, he pushes the pedal down and a little air comes back out, we did this several times and the same thing happens...

With the bleeder open, if I put the power bleeder cap on and pressurize the reservoir, shouldn't fluid come rushing out the bleeder? I tried this and nothing comes out, not with the pedal up, nor down nor anywhere, it just has be baffled!

but this manual method didn't work at all...

I'm going to try pushing with the power bleeder again, but if this doesn't work I dont know what to do except to start taking it apart. and that just doesn't seem right because it was working just fine when I took the clutch out, and the master and slave are fairly new, I know they didn;t go out just by sitting in the garage on jack-stands for 2 weeks!
BTW, Anybody got a use for a couple hand-fulls of hair???

mholme
07-25-2010, 04:14 PM
Is your car level, either elevated or on the ground? You'll have a hard time getting air pockets out if it isn't. Also, if you do it the old fashioned pimp the pedal method, put your fluid collector and bleed line high above the slave, resting somewhere on the engine, not the ground.

Seerlah
07-25-2010, 04:15 PM
Walky was saying the pedal being limp is normal. My last post just coincided with your last one. What Walky was stating is you need to pump the pedal a few times (with bleeder valve closed) before you can go into the bleeder procedure.

Edit: I actually think Walky was saying to pump it 5-10 times "in between each time" you crack open the bleed valve. Meaning you would do it like any other pump clutch bleed method, except with 5-10 pumps in between each time you open the valve, and have the clutch pedal in the downward position everytime you open the valve.

Also, I aplogise. I think you are to have the pedal pressed in the down position when you open the valve. I used the power bleeder when I did mine, but my mehcnic gave me instructions on how to do it manually if need be, and I think I just got that part confused (up and down position of pedal when opening valve). So yeah, pump it like 5-10 times via walky's advice. Holding the pedal down on your last pump, open the valve, and repeate as necessary. I am pretty sure that is what Walky meant.

Seerlah
07-25-2010, 04:33 PM
that doesn't work at all, he brings the pedal up, I open the bleeder and it sucks air in, he pushes the pedal down and a little air comes back out, we did this several times and the same thing happens...



I just gave it some thought and it makes sense. You need to have the pedal down to the floor while opening the valve. I guess the part I overlooked was "you always need to have the pedal to the floor when opening the valve". I was just going by what my mehcnaic told me, and I have never attempted it myself. If I did, I would have known to keep the pedal to the floor when opening the vlave. Once again, I aplogise. But instead of pumping it once and holding it to the ground, Walky is saying 5-10 times and then holding the pedal to the ground and open the valve.

walky_talky20
07-25-2010, 04:33 PM
Yep, that's what I meant:

1 - Close bleeder valve, if open
2 - Pump pedal 5-10 times, slowly.
3 - On the last pump, hold pedal at the floor
4 - Open bleeder
5 - Close bleeder
6 - Pump 5-10 times slowly, etc...

I doubt you are doing it wrong, it is pretty simple. If it hasn't worked for you by now there may be something wrong somewhere. Give it another shot and see what you get.

2001A4QUATTRO
07-25-2010, 04:46 PM
That is not how you are supposed to bleed clutch systems.

1 - Close bleeder valve, if open
2 - Pump pedal 5-10 times, slowly.
3 - Open bleeder
4 - Push pedal to the floor, hold pedal at the floor
5 - Close bleeder
6 - Repeat

Good luck

Seerlah
07-25-2010, 04:55 PM
I am rather confused why the power bleeder didn't work either, also? That's how I bled mine and worked just fine at 15psi.

2001A4QUATTRO
07-25-2010, 05:06 PM
^^^ Agreed.

1NaudiA4
07-13-2011, 02:53 PM
Brining this back from the dead.

I'm having the exact same problem as JK35.

Did a full brake line change and flush and while I was at it I decided to flush the clutch line as well. Hook up my motive power bleeder and pump it up to 36psi, push down the clutch, open the bleed valve and let the fluid out, close it and pull up the pedal. Now there is no more resistance on the pedal. I tried keeping the pedal in the resting position with the power bleeder hooked up but no fluid comes out. I've also tried the pump/bleed method about 25 times to no avail. There is absolutely no resistance in the pedal.

Before I tried bleeding it I tested out the clutch and everything seemed fine so I don't know why this would be happening.

Any ideas?

1NaudiA4
07-14-2011, 07:08 AM
Solved!

Wow do I feel like an idiot. After trying to bleed the damn clutch all day I finally took off the hose going from the brake reservoir to the clutch master cylinder and realized that there was no fluid in the hose. I figured maybe the reservoir was plugged up so I tried to stick a screw driver in the nipple for the clutch master cylinder. The nipple for the clutch master cylinder was completely sealed from the factory! As in I had to cut the tip off of it. The scary thing is I had been driving around for three years like this with out any problems. After I figured that out I simply hooked up the power bleeder to the reservoir and had it bleed in 2 minutes[headbang]

metafizz
07-09-2013, 06:18 PM
+1 to this, totally did my head in until I read 1NaudiA4's post and like him had it bled in two minutes. Besides thinking it must be the way to go for faster assembly from factory, I'm still wondering why the outlet of the fluid reservoir is blocked for the clutch

seanf86
07-10-2013, 05:36 AM
I had a similar problem on my b6, after hooking up a power bleeder and pumping and pumping and nothing, it ended up being a bad clutch master cyl, installed a new one and now I can gravity bleed the slave with no power bleeder