Clutch bleeding issues.....

petex19

petex19

True Classic
Now that the '74X is running like a top again I can concentrate on the issue the car had from the day I bought it for my son. The clutch pedal just falls to the floor when I step on it so the car won't go into gear.

The PO said the pelal just dropped to the floor one day so the car sat until I bought it. The PO purchased from Vic's and gave me still in the boxes, clutch slave cylinder, clutch master and complete clutch assembly.

I followed the steps from a very interesting Youtube video on clutch bleeding using a vacuum, a jar and a piece of clear tubing and it seemed like it was really working sucking all the air bubbles out of the system but the clutch pedal was still dropping to the floor and staying there so I installed the new clutch slave cylinder and bled for a couple of hours and the pedal doesn't just fall to the floor quickly as it used to but it still doesn't come back up.

I had enough for one day but will try again next day off. I'm trying to get my hands on a pressure bleeder that connects to the reservoir and give that a try or should I replace the clutch master since I already have the part. Is there any way to test or know if the clutch master needs to be replaced.

Don't ask me why the PO purchased a complete clutch assembly as well as the other clutch parts as I can only imagine that since he was placing an order to be shipped to Canada then he just bought everything that it could be, I guess. What has me a little concerned is that I can't put the car into any gear when sitting in it. I should be able to put the car into gear with the engine off and without the clutch engaged shouldn't I ?

'PeteX1/9
 
Myself and a friend just bled my clutch system today. How we did it (and I suggest utilize your son) was we took the cap off the reservoir and topped it off, he the loosened the bleed nipple and attached a thin hose from the nipple into the can of brake fluid and I pushed the clutch pedal to the floor and held. He then tightened the nipple preventing air from reentering the system as I manually moved the pedal up. We then repeated this process several times until the air was all out and the clutch had good feel.We then topped off the reservoir and tightened the cap and job done. Only took us a total of around 7minutes start to finish. If you've spent all day, I'd check the slave line and other lines in the system as that can really be the only way air is entering the system. Check that the bleed nipple is in fact tightened.
 
I went through this just a couple of months ago. I first bled at the master cylinder before moving back to the slave. Took me some time to get all the air out. Don't get frustrated, good luck.
 
Since the car is old,

Change both the slave and master cylinders.

The problem with the master is that it is located at an angle that traps air. Jacking up the rear of the car helps when bleeding. The pedal will drop to the floor, use a short length of rope and tie to the pedal to bring back up. You should get about 1 1/4" of travel at the slave cylinder. If you don't then there is still air in the system.

When bleeding make sure you press the pedal all the way to the floor. Some cars have a pedal stop on the floor to limit the travel, remove it when bleeding. Also make sure that the floor mats do not limit the travel of the pedal. It is frustrating and poor design that takes more time to do then one thinks.

TonyK.

Grimsby Ontario Canada.
 
Try bleeding from the master cylinder...

You might have more success bleeding from the master cylinder first. Just crack open the output and put plenty of rags on the floor...

Cheers,
Dom.
 
Clutch bleeding...

To answer your last question first, you'll only be able to crunch into gear with the clutch pedal up about 1/2 the time, random.

Search the archives for info on this detail, the rod of the slave needs to be (in? out? a little to expose the internal passage for bleeding. Maybe you have this figured out.

I prefer to use the pressure bleeder, but be aware that the reservoir is old and brittle and as little pressure as you can get away with is all you need.

Putting the nose in the air and letting it gravity bleed is an option.

Vacuum bleeding works unless air is drawn past the threads of the bleeder into the stream, some folks put teflon thread seal tape on the bleeder threads to prevent this. Also makes later maintenance easier.

If nothing makes the pedal action better after a lot of bleeding of the slave, then it's likely the master is worn out. Sometimes it will leak to the outside (check behind the dust boot) but sometimes the leak is internal. Pedal bleeding can also exacerbate this; many a usable clutch and brake m/c has been ruined by pedal bleeding. Pedal bleeding runs the seal past typically unused areas of the bore which are usually corroded and wear out the seals. This is especially true of the brake m/c.

Hope this helps, this can sometimes be one of the worst jobs on the X. If you are even thinking about changing the m/c, start using penetrant on the nuts 2 weeks ago. :)
 
I replaced master and slave recently and I filled the reservoir, cracked the nut on the line out of the master and pushed the pedal until I started to make a mess, closed it, moved back to the banjo nut fitting on the slave, did the same, then the slave bleeder. I didn't think I had it good enough as I didn't quite have the 1+" of travel at the slave push rod but after a test drive it felt great and I've put on a couple thousand miles since so, well if it ain't broke (anymore) stop fix'n it!
BTW I had the exact same symptom; pedal when straight to the floor and stayed there suddenly.
 
Interesting that you mention the rod in the slave cylinder because I've been wondering since yesterday if that is the most of my problem right now meaning I bled using the vacuum method and in just a short time I bled probably two reservoirs worth which went from very dark almost black to clear as what was going in. The bubbles appeared to have disappeared but I assumed the slave cylinder must be toast because the pedal was still going to the floor and staying there. I had a brand new slave still in box so I installed it but I may have installed the rod incorrectly as I never got another drop of fluid into my jar with the new slave just air seemed to be going through the clear tube. I tried putting the pedal up and down and it seemed to make no difference. I'm sorry for the wordiness but what I'm trying to say is before I removed and installed the new slave cylinder although alot of bubbles the fluid was able to travel through the clear tubing to my jar and now only air ? My manual just says to remove rubber boot and insert rod so how do you know that you've installed it correctly will it lock or is there a set amount that you insert it and those two retaining nuts that go on the threaded rod where exactly are they supposed to sit ?

'PeteX1/9
 
I doubt the rod has anything to do with it. The slave has an internal piston that pushes the rod. Try to bleed the slave with it slightly extended. I remember reading it won't bleed well if the slave's internal piston is "in" all the way. Not really sure how you'd do that. Try cracking that banjo fitting where the line enters the slave and bleeding there a bit, then tighten, then try the slave's bleeder, you can also try bleeding the slave while it is unmounted, allow you to turn it a bit and tease the air out. These are just things I remember reading. I had no trouble bleeding my system.
 
I recommend power bleeding.

Empty and then remove the reservoir and the hose from the reservoir. Using a power bleeder attached to the hose from the reservoir to the clutch master cylinder, open the bleeder on the slave cylinder and push a pint of clean fluid through. You should stop part way through the pint (no not the Guinness, you should drink that right down) to see if you have pedal.

Don't use a ton of pressure, you don't need a lot of pressure to move the fluid through the system.

You can make a power bleeder from a garden sprayer, buy a small 1 gallon unit with a wand and trigger, fit a hose to the end of it to be the intermediary from the wand to the hose on your Fiat.

Make sure your hoses are in good condition and clamps tight, you don't want to clean up a quickly escaping pint of brake fluid.

Given the weak nature of the reservoir on our cars I don't pressurize it unlike most approaches which use a cap with a Schrader valve in it.

http://www.bmw-m.net/TechProc/bleeder.htm

http://faculty.ccp.edu/faculty/dreed/campingart/jettatech/bleeder/index.htm
 
The leak is in the hard line behind either going to or coming from the clutch master. While my son was pumping the clutch by hand since it won't return by itself yet he said he heard a hissing while he was pumping so I checked it out and seen that the clutch fluid was coming out of the hard line just above the gas pedal. I've never worked with hard lines and just know that special tools are used to work with them.

Hopefully someone with some experience with hard lines can comment on a possible fix.

Is the hard line a one piece item from the clutch master to the slave that I can replace or from the reservoir to the clutch master or can the section with the break in it be cut out and a new section be placed in however that is done. Just a guess but I'm thinking that the break is in the section between the master and the slave since the hard line appears to go under the center console tunnel shortly after the break.

'PeteX1/9
 
Can you see the break right in the line? Are you sure it's not leaking at the fitting and running down the line a ways? Odd place for a "break" I'd think. When I did the clutch master I had to drop steering column/pedal box and all just to get enough room for a flare nut wrench with a vise grips over it to prevent slippage. Lot of work but worth it to not strip the nut and have to redo the hard line. Maybe you're "lucky" and the fitting just isn't seated well?
 
Yes I can see the break in the line as I pumped the clutch with my hand repeatedly just to make sure that I wasn't seeing things. The break is midline though, not at any joint or fitting so how if possible can it be repaired or replaced ?

'PeteX1/9
 
WOW!!! That is exactly what I need and I unfortunately just recieved my Midwest order but more importantly how on earth would you install that hard line through the tunnel and firewall without bending the crap out of it ? I was hoping to be able to cut out the bad section that consists of 1 centimeter but I would cut out a few inches of course and attach correct fittings and a new section but having never done it before I don't have much confidence in my flaring abilities.:mallet:

I'm wondering if it would be easier to disconnect it at the master and cutting the line after the split part and I can at least have a new hard line prepared professionally out of the car by a shop but I would still have to prepare the flair and connection where the new section would attach, grrrrr!

'PeteX1/9
 
Well today I decided to jump into the repairing or replacing of the hard clutch line but as it turns out I was wrong and the line is fine but the clutch master looks like crap. It must have been leaking from by the rubber boot and the fluid was running down the clutch line which led me to believe the hard line was split. So I dropped the steering column and the pedals and replaced the master which was a PITA for obvious cramped work space but with the steering wheel removed it really wasn't that bad. Replacing the throttle cable on my '84X last year was much worse for sure.

Before I re-assemble everything I just want to be sure that I've installed the master correctly. The little push rod just rests up against the master inside the rubber boot and that's it, meaning it doesn't fasten to it in any way?

I was wondering if I should fill the clutch fluid reservoir and try bleeding a bit before completely re-assembling everything to be sure of no leaks?

'PeteX1/9
 
Well I was right for once. :headbang:
I believe you're right, the push rod just sits in there.
yes, I'd bleed the master by filling reservoir and cracking open the hard line fitting exit point and letting it push out there, then tightening, then moving to banjo fitting on slave, crack open, let fluid come out, then the slave bleed nipple.
If you've already buttoned up everything surrounding the master you might just skip that first step and only go back in if you can't get it.
 
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