Page 1 of 1
Frustrated - Cortina Clutch!
Posted: Wed Sep 02, 2009 10:44 pm
by angliagt
After over 1 year,I've got the Cortina running.
Rebuilt engine,transmission.
I can't get the clutch to disengage properly.
Any ideas?
- Doug
Posted: Thu Sep 03, 2009 1:29 am
by JAN
The lining has stuck to flywheel, not uncommon with a car that's been standing for some time.
USUALLY it will free by putting it into first gear and turning the key; this will start the engine and cause the car to jerk forward. Keep the accelerator floored and jab the foot brake on and off repeatedly. The shocks usually release it. And no, it doesn't cause damage.
If it doesn't free, you'll have to take the gearbox out.
Posted: Fri Sep 04, 2009 12:37 am
by angliagt
It drives - will shift once underway.I'm thinking that
there's an air bubble still in the line.
- Doug
Posted: Fri Sep 04, 2009 12:51 am
by JAN
Ah, not the same thing! Is the clutch rod at the bellhousing adjusted correctly? There should be only 1/10" free movement. If so, get someone to press the clutch pedal and see how far the end of the fork moves; should be getting on for a couple of inches.
Posted: Fri Sep 04, 2009 10:20 pm
by angliagt
After talking to a mechanic.I've decided that it would
probably be best to take clutch master & slave cylinders
off of the vehicle & "reverse bleed" (pushing the slave manually-
to the master cylinder),& see if I can clear any air from the sys-
tem.
We have a local car show next weekend,& I don't know
weather to take the Cortina,or the TR6.Since I have our Grand-
daughter,I'll probably take the Cortina.
- Doug
Posted: Wed Sep 30, 2009 6:34 pm
by Dave A
I used to have great difficulty with bleeding these until I discovered how to reverse bleed it on the car. It's easier to force air bubbles uphill than it is downhill. All you do is have the master cylinder pretty well full, reach down and pull the clutch release lever forward all the way until the push rod is bottomed out in the slave cylinder and release slowly. Do this several times until most of the air bubbles have risen up out of the master cylinder and that's all there is to it. Do not open the bleeder screw.
If this doesn't work you may want to make sure you have the proper 7/8" bore slave cylinder on it. This should be stamped into the outer casing of the slave. Putting a master cylinder with a larger bore should give you more travel (at the expense of a harder to push pedal) likewise a slave with a smaller bore should increase the travel. Other causes other than the releasing of the clutch is a dry pilot bearing in the back of the crankshaft that keeps the trans input shaft turning some even though the clutch is fully released.
Do not put an adjustable push rod on the slave cylinder. The proper push rod is a predetermined length and is not adjustable. Putting an adjustable rod will not help as it will only serve to push the slave piston back deeper in it's bore and will not increase the actual stroke because they are a zero freeplay system anyway. What I mean is the spring inside the slave keeps a slight pressure on the push rod which keeps the throwout bearing in contact with the pressure plate fingers at all times.
This stuff I learned 30 years ago as a frantic teenager determined to have the car mobile that day. I worked about 8 hours straight until about 3.00 AM trying to get a clutch pedal. Finally I accidentally discovered the reverse bleed and I was off and running. Let me know how you get on with it.
Posted: Wed Sep 30, 2009 6:41 pm
by Dave A
You can also look up under the dash and make sure brake fluid is not leaking out around the push rod boot. There is basically one main seal in the master and if it isn't doing it's job properly, the fluid will leak by the seal and out the back of the master instead of being forced down the line toward the clutch.
Posted: Fri Oct 02, 2009 9:45 am
by peteleo
Dave,
Good advice on alternative way of bleeding the clutch hyd.
I just want to mention to use the correct type brake fluid as some of the older rebuilt kits are made of natural rubber esp. Lucas/Girling kits.
If you are using these kits you must use Castrol brake fluid because it is a mineral based fluid and won't swell the seals. Silicon brake fluid is also ok to use which is even better because it won't absorb moisture and won't swell the seals.
Is there suppose to be a spring inside the MK2 slave cylinder ? I know there is a external spring attached to the MK1 fork.