Clutch Problem on Jack's 40 (1 Viewer)

[Von Hayek]

Dad was on Main Street in Annapolis and, when pressing the clutch, he met an obstruction of some sort that gave him a lot of resistance at the pedal. He pushed on through it and the clutch started to fail. It did not instantly fail, but failed over a short time. He could pump it up to shift and got it my place.

We had replaced the slave cylinder last year, so I assumed it was the master. We replaced the master, bled it where the hard line comes into the master, then bled it at the slave but it is still soft. I really don't think there is any air left in the system as we bled and bled.

Any suggestions?

 

[Stumpalama]

Do you get movement in the slave? You can see it by laying under the passenger side while someone presses the clutch.
Also, you can pull the lower flywheel cover off and observe the action of the clutch arm and bearing on the clutch plate.

 

[Jakes40]

2X on check for moving slave/clutch arm.
Sounds like a Master. I got an Asin off of Amazon.

 

[Von Hayek]

Affirmative on both--the slave moves some, and the clutch actuates. We replaced the master and the feeling was the same according to Jack. But honestly, it feels like there is air in the system. But man did we do a lot of bleeding.

My thoughts are:

- The cheap Chinese slave we put in last year failed and, though it is moving, not moving like it should.
- Not knowing enough about actual clutch operation, something in there broke. But looking at it, all of the spring teeth are in place and the throwout bearing moves without problem.

 

[76FJ40]

When you bled the master did you just let fluid run out the hole where you disconnected the hard line or did you attach a tube that you kept submerged in brake fluid? Do you see fluid coming out the weep hole on the slave?

 

[Von Hayek]

When bleeding the master, the hard line was attached and there was fluid in the system. Jack would pump the pedal and hold, and I would crack the fitting then close it. Did it many times.

I did not notice any fluid coming out of the weep hole for the slave cylinder.

 

[JohnVee]

OEM. Not very expensive. At least you'll probably start out with good stuff.

 

[Stumpalama]

When bleeding the master, the hard line was attached and there was fluid in the system. Jack would pump the pedal and hold, and I would crack the fitting then close it. Did it many times.

I did not notice any fluid coming out of the weep hole for the slave cylinder.

Aisin is your friend WRT to clutch and brake cylinders.

For true "bench bleed" of a master, you connect a hose to the output of the master, feed it back up into the reservoir, fill the reservoir, and cycle the piston. this ensures there is not air sneaking back into the master.

 

[iptman]

I did the modified bench bleed by connecting a hose between the slave bleeder and master res. Then just pump the clutch until you don't see any more small bubbles pass back in to the reservoir. Obviously you want to make sure there's no junk coming out of your slave but when I did it I replaced both cylinders and let the brake fluid fully drain out of the slave hard line. I think about 50 pumps did the trick for me.

Bonus, this is a one man op.

 

[Von Hayek]

So I guess the consensus that I am hearing is that there is still air in the line.

 

[Stumpalama]

So I guess the consensus that I am hearing is that there is still air in the line.

That, or the plunger on your master or slave tore... That's the best I can do without seeing it in person.

 

[Blue77FJ40]

If it was me, I'd install OEM clutch master and slave as a pair. Anything else is likely to be problematic. As JV said, it's not that expensive and you'll thank yourself once installed. I'd even suggest carrying a spare slave. I had one blow out on me at a GSMTR on one of the trails and Skelley was kind enough to run back to camp and grab my spare slave. Ten minutes after he returned, I was back in action. Good luck.

 

[Von Hayek]

We have an Aisin slave sitting on the shelf. I suppose our next course of action will be to replace the slave (again ) and try to bleed the master a little better.

 

[TRFCSUX]

Look at the firewall inside the cab. Above the pedals. Peel the vinyl back and see if it’s wet. I’m guessing you are leaking

 

[emorth]

I have a vacuum pump and smoke generator if that helps find a leak.

 

[Stumpalama]

I have a vacuum pump and smoke generator if that helps find a leak.

Not for this problem Ed. Though watch where you mention your vacuum pump. (just friendly advice, unless of course you are trolling for dates)

 

[emorth]

Well that really sucks.

 

[1MOA]

Look at the firewall inside the cab. Above the pedals. Peel the vinyl back and see if it’s wet. I’m guessing you are leaking

This,,,,also get it cleaned up it will take the paint right off your firewall and floor

 

[Von Hayek]

We already replaced the master, and it was not leaking through the firewall. Though there was clearly some leaking there years ago, evidenced by the peeling paint and surface rust. We cleaned that up and hit it with some paint.

The problem persists after we replaced the master. We'll replace the slave cylinder and re-bleed this afternoon and see what happens.

 

[Stumpalama]

We already replaced the master, and it was not leaking through the firewall. Though there was clearly some leaking there years ago, evidenced by the peeling paint and surface rust. We cleaned that up and hit it with some paint.

The problem persists after we replaced the master. We'll replace the slave cylinder and re-bleed this afternoon and see what happens.

What brand is your master?