Now the clutch wont bleed (pic)

BrianM

BrianM

'74 - Blue Bomber
Hi Team,

Replaced the clutch master because I was replacing the break master and had the whole assembly out.
After much nonsense and cursing I finally got the brakes sorted.
Brake Link

But now the clutch slave wont bleed. It won't even weep. I tried all my tricks: Vacuum at the slave nipple, Pressure pot at the reservoir. Pressure and Vacuum, and peddle pumping. No Joy, not even a drip. I found MOREJ's Fix here in the workshop. Tried pushing fluid back up the line with a syringe and nothing flowed. Finally cracked the line at the firewall fitting and lots of fluid. This leads me to believe the Slave Cylinder, might have frozen or sealed up on me in some way.

I was also perplexed that the return spring was missing, and the adjustment was pretty much all the way out.

I'm probably just going to order a new slave they are cheap insurance. But MWB is out of return springs, anybody got one???

Also just read that some new Slave cylinders don't have the correct gap at full retract and need to be modified to bleed?

Thoughts?

Clutch_9075.jpg
 
Bleeding issues are common and can be very frustrating to solve. However I would agree with your idea of replacing the slave cylinder. Hard to say if that is the reason for the lack of fluid flow. But even if it isn't bad (yet), it likely will be soon enough. Also, following @JKIDD advice, replace all of the rubber flex hoses (brakes and clutch) while you are at it. Nice to have everything new.
 
Hi Brian. Firstly....are you 100% sure you installed and adjusted the new clutch master correctly ? That is...there should be a hair of free play between the pushrod and the end of the master when at rest. I recall that happening to someone here a few months ago.....Insufficient adjustment would mean the inlet port to the master being fully or partially blocked and lead to all kinds of weirdness.

If that is all okay...check for a kinked reservoir hose.

If you suspect something funky going on at the slave.....no reason you cant just try bleeding ( by pressure or pumping ) at the slave ......not by the bleed nipple...but instead at the line going into it !! Just treat that inlet union nut as a bleed nipple. Can get a bit messy....but that is good if fluid is peeing out there.....

Good luck !!
 
Try to discover where the brake fluid is stopping to flow. In my case, the rubber braided lines thru the firewall were too tight and the fluid wasn't even reaching the master.
 
That slave is stuffed :) So all bets are off until you get a new one. Good practise to do new [or at least rebuild] slave and master together. If you fix one and not the other, the new strong item quickly kills the weak item anyway.
 
rx1900 said:
Hi Brian. Firstly....are you 100% sure you installed and adjusted the new clutch master correctly ? That is...there should be a hair of free play between the pushrod and the end of the master when at rest. I recall that happening to someone here a few months ago.....Insufficient adjustment would mean the inlet port to the master being fully or partially blocked and lead to all kinds of weirdness.

If that is all okay...check for a kinked reservoir hose.

If you suspect something funky going on at the slave.....no reason you cant just try bleeding ( by pressure or pumping ) at the slave ......not by the bleed nipple...but instead at the line going into it !! Just treat that inlet union nut as a bleed nipple. Can get a bit messy....but that is good if fluid is peeing out there.....

Good luck !!
Click to expand...
Hi. Yes I rolled the clutch peddle stop all the way back to make sure the cylinder sets all the way back. Resv our lines are all new. I’ll double check for cinks.
 
Not sure if this will help, but I have found on some slaves, if the piston is pushed all the way back, it will not bleed. I suspect it covers the bleed screw area when pushed all the way back. Really glad you were able to resolve the leak.
 
BrianM said:
Yes it’ll work but the return spring keeps the throw out bearing off the clutch.
Click to expand...
It does, but that serves more to make adjusting the free play easier than anything else, it's not a crucial function. Check out the five speed clutch arrangement - the spring is mounted to the bell housing and holds the release bearing against the pressure plate, so as to avoid the need to periodically adjust the free play.

I find that extending the slave rod an inch or so (back off the adjustment nut to allow the extension) bleeding some more, and then slowly forcing the slave back in with the bleeder open (again, use the adjustment nut) helps a lot. An additional trick that I've tried with mixed results is bleeding with the slave unbolted so that it can be rotated to bring the bleeder end up - especially with the sideways bleeder on the four-speed slave.
 
I have to disagree about the need to pull the throwout bearing away from the pressure plate. :eek: I think it's pretty important. I know the later 5spds held it against the pressure plate, but that means the throwout bearing is always spinning at engine speed, that has to wear the throwout bearing, and the pressure plate, faster. IMO it's better to run the risk of needing to adjust the free play (which is almost never necessary) than replace a throwout bearing/pressure plate.

Be careful if you unbolt the slave cylinder from the mount, unless you're careful you can pump the piston right out of the slave. The way the slave is mounted on a 4spd is not a good design either. Better to replace the 4spd slave mounting bracket with a 5spd mounting bracket. That gets the bleeder orientated up. Best IMO to replace the whole 4spd set-up with a 5spd set-up (but only if you've got your trans out already!).

I sometimes bleed the clutch myself by pressing down on the clutch pedal with a long broom stick. Use the steering wheel to hold it up and make it a one man job. :)
 
I would agree with @MikeHynes about the need to pull the throwout bearing away from the pressure plate. Having it run all the time seems like bad practice. I've worked on many manual transmission cars, and the only ones I've seen that keep the throwout bearing running all the time is the X1/9 five speed.

As far as replacing a 4 speed with a 5 speed, I'm not so sure. I have a suspicion that the 4 speed using Tripode joints may be more power efficient than the 5 speed due to the more severe CV joint angles. Looking at some power loss vs. angle charts shows that it does not take much angle to start losing efficiency. I don't have the numbers for max angle for the 4 speed versus 5 speed but the longer driveshafts on the 4 speed would make those angles smaller. If I went to a 5 speed, I might be inclined to look for one of those old Coletti 4 speed to 5 speed conversions. They also have much closer ratios available for performance applications. Don't know if they still exist anywhere but FAZA used to sell them back in the 70s.
 
I thought the photo of the gearbox looked odd. Its a 4 speed! I have only ever worked on the 5 speed so didn't appreciate the difference.
 
Don,
II wasn't clear about changing the slave cylinder mount from the 4spd style to the 5spd style, that's all that I was recommending (well that and the arm that actuates the throwout bearing - if you have the trans out.) I just think that the slave cylinder mounting bracket is better on the 5spd, and it interchanges on the 4spd.
BTW - the 4spd, w/axles etc, is a lot lighter than the 5spd w/axles etc.
 
dllubin said:
Tripode joints
Click to expand...
tripod joints are more efficient full stop. Also stronger and lighter for a given torque and also smaller :) The single advantage of the other type is greater possible operating angle and the only reason they appear on the X is because the powerpack is primarily for front wheel drive. FIAT moving to better steering lock on the FWDs.
 
Steve Thomas said:
tripod joints are more efficient full stop. Also stronger and lighter for a given torque and also smaller :) The single advantage of the other type is greater possible operating angle and the only reason they appear on the X is because the powerpack is primarily for front wheel drive. FIAT moving to better steering lock on the FWDs.
Click to expand...
I suspect that manufacturability may have also played a role since the 5 speed approach also makes the subassemblies a bit more modular and less dependent on each other and how they go together. The Tripodes require most of the rear end to be together before you can even add transmission fluid. Also, they don't have to deal with the delicate installation of the Tripodes with their needle bearings that don't take much to fall out into the transaxle.
 
dllubin said:
I suspect that manufacturability may have also played a role since the 5 speed approach also makes the subassemblies a bit more modular and less dependent on each other and how they go together. The Tripodes require most of the rear end to be together before you can even add transmission fluid. Also, they don't have to deal with the delicate installation of the Tripodes with their needle bearings that don't take much to fall out into the transaxle.
Click to expand...
Note that they went back to tripods on C514 boxes I think tripods are cheaper too. The machining etc is very simple.
 
BrianM said:
Hi Team,

Replaced the clutch master because I was replacing the break master and had the whole assembly out.
After much nonsense and cursing I finally got the brakes sorted.
Brake Link

But now the clutch slave wont bleed. It won't even weep. I tried all my tricks: Vacuum at the slave nipple, Pressure pot at the reservoir. Pressure and Vacuum, and peddle pumping. No Joy, not even a drip. I found MOREJ's Fix here in the workshop. Tried pushing fluid back up the line with a syringe and nothing flowed. Finally cracked the line at the firewall fitting and lots of fluid. This leads me to believe the Slave Cylinder, might have frozen or sealed up on me in some way.

I was also perplexed that the return spring was missing, and the adjustment was pretty much all the way out.

I'm probably just going to order a new slave they are cheap insurance. But MWB is out of return springs, anybody got one???

Also just read that some new Slave cylinders don't have the correct gap at full retract and need to be modified to bleed?

Thoughts?

View attachment 81403
Click to expand...

A couple of thoughts:

- check that the feed line from the reservoir isn't kinked as it comes through the firewall
- try to crack open the hard line on the master and make sure you are getting fluid there (with a towel on the floor!). Once you have let some of the air out there you will have a better chance of bleeding the slave.

Cheers,
Dom.
 
Fixed, well 99%. New Slave cylinder arrived and to the credit of the list here was blocked off from bleeding. Looking in the bleed hole I could even see the piston was blocking the exit hole. A gentle shove with a tiny screwdriver on the supply hole and the piston moved easily. Hooked it all up and still could not get it bleeding with vacuum or pumping pedal. The air pressure cap that MWB sells did the trick just fine, pushed lots of ugly fluid out. Clutch works like a charm, but needs a bit of adjustment and a return spring. I was able to finally drive the car with the new upgraded brakes, which was the goal of this whole adventure.
Unfortunately the slave cylinder and flex line do not come with the required crush washers. I re-installed the old ones and now have a slight drip, New washers on order.
Thanks Team, if not for that tip on the blocked bleed hole I would have installed that Slave cylinder and hit the same snag.
 
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