Struggling to bleed internal slave

[CrustyBoy]

Hey all,

 

So I'm about 99% finished swapping my BA10 for an AX15. At this point I need to get the clutch operating correctly and I can test drive it..

 

I'm all by myself so I've only been able to try vacuum bleeding and gravity bleeding so far. Neither have worked yet. I can't tell if I'm not bleeding the clutch properly, or if I made a big mistake by machining my flywheel. It seems like I've bled out most of the air, the clutch pedal gets nice and stiff after pumping it for a while when it's all closed up. But I can't get the trans to go fully into neutral with the pedal down. I can force it into first and second gear and it will engage. But when I press the clutch pedal in the tires keep spinning. Trying to go into reverse produces a horrifying grinding noise.. Is there some magic trick to get an internal slave system fully bled? Could it be that the flywheel is just too thin now that it's been resurfaced?

 

Crusty

[pizzaman09]

I have had a recent set of issues with my clutch hydraulics.  I found gravity bleeding to be bay far the most successful and easiest way to bleed it.  I just opened the bleeder on the bottom, and kept pouring in fluid up top.  Probably let that occur for 15 minutes then closed the bleeder.  It was bled perfectly, no pumping required.  

What is the condition of your master cylinder?  Are you sure the piston is coming all the way back out when you let off the pedal?

[CrustyBoy]

On 3/4/2023 at 9:37 AM, pizzaman09 said:

I have had a recent set of issues with my clutch hydraulics.  I found gravity bleeding to be bay far the most successful and easiest way to bleed it.  I just opened the bleeder on the bottom, and kept pouring in fluid up top.  Probably let that occur for 15 minutes then closed the bleeder.  It was bled perfectly, no pumping required.  

What is the condition of your master cylinder?  Are you sure the piston is coming all the way back out when you let off the pedal?

 

I am assuming the master cylinder is original to the car. I don't know how to tell. It's definitely old and dirty. I suppose I will try a new one with a new line as well and see if I have any luck.

[pizzaman09]

16 minutes ago, CrustyBoy said:

 

I am assuming the master cylinder is original to the car. I don't know how to tell. It's definitely old and dirty. I suppose I will try a new one with a new line as well and see if I have any luck.

An easy way to know if the piston is sticking is if you have a lot of slop in the pedal prior to it feeling like it is making pressure and pushing on something.  It could have like 1/4" of slop but if you have much more the piston may be sticking.

[cruiser54]

New clutch disc by chance?

 

Try this. Bleed it as best you can. 

Pump the clutch pedal about 50 times without pushing it all the way to the floor. Just shy of that.

walk away for 20 minutes and see how the pedal feels. 

[CrustyBoy]

13 hours ago, cruiser54 said:

New clutch disc by chance?

 

Try this. Bleed it as best you can. 

Pump the clutch pedal about 50 times without pushing it all the way to the floor. Just shy of that.

walk away for 20 minutes and see how the pedal feels. 

 

Yes, resurfaced flywheel, new clutch disc, new pressure plate, new internal slave. All in a new-to-me 1993 AX15. I can get the pedal feeling pretty darn firm, but the throwout bearing is clearly not pushing all the way into the pressure plate like it should.

 

I am leaning toward trying a new master cylinder and line. Maybe I pumped air into the line and messed it up? Can anyone recommend a bolt-in replacement?

[cruiser54]

Did you try the 50 pump suggestion?

I'm trying to walk you through something here. 

[CrustyBoy]

1 hour ago, cruiser54 said:

Did you try the 50 pump suggestion?

I'm trying to walk you through something here. 

 

Didn't mean to imply I wasn't going to try - Will do that very soon and report back.