Clutch disengages at the floor

mattv228 · Post by **mattv228** » Thu Dec 05, 2013 5:40 am

when i bought the car it had some clutch issues. well after replacing everything. new disc, slave cylinder, master cylinder and hose and bleeding it multiple time. what would cause the clutch to disengage when pedal it against the floor. would the wrong hose being used from the reservoir to the master cylinder do it? maybe same from master to slave? i noticed its not the normal blue hose like my friends. and his disengages pretty much near the top. would it be best just to get the stainless steel line?

Brucey · Post by **Brucey** » Thu Dec 05, 2013 6:57 am

these clutches can be tricky to bleed out, so I'd have another go at that first. If you search for old posts there are a few different techniques that people have used with success.

It is extremely unlikely that the type of hose (feed or pressure) will affect the way the clutch works, except inasmuch as it affects the way the system bleeds out.

Failing there being air in the system it is possible that there is a fault inside the bellhousing, e.g. with the clutch arm or release bearing.

Obviously you will not be happy if you go tearing into that lot and you later find it is just a hydraulic fault.

cheers

mattv228 · Post by **mattv228** » Thu Dec 05, 2013 7:09 am

Brucey wrote:these clutches can be tricky to bleed out, so I'd have another go at that first. If you search for old posts there are a few different techniques that people have used with success.

It is extremely unlikely that the type of hose (feed or pressure) will affect the way the clutch works, except inasmuch as it affects the way the system bleeds out.

Failing there being air in the system it is possible that there is a fault inside the bellhousing, e.g. with the clutch arm or release bearing.

Obviously you will not be happy if you go tearing into that lot and you later find it is just a hydraulic fault.

cheers

ive had it professionally all done a bled twice. he replaced the pivot arm inside the bell housing also and new throwout bearing. so im at a loss at the moment.

Brucey · Post by **Brucey** » Thu Dec 05, 2013 7:43 am

OK maybe there is something weird going on. Some ideas;

- is the clutch pedal hitting a stop of any kind? If it is, the compensation port in the MC may not open fully and this will make the clutch impossible to bleed properly.

- is the clutch a matched set of parts?

- did the clutch come apart for inspection when the arm etc was replaced?

-are you sure the bore iszes of the MC and slave are correctly matched to one another?

In the simplest terms there are only two possibilities; either-

a) the slave cylinder isn't moving far enough when under load, or

b) the slave cylinder is moving but but the clutch isn't disengaging.

On the latter point I once had a clutch driven plate break up (the rivets failed and the damper springs escaped...) and the first sign all was not well was that the clutch didn't disengage until the pedal was on the floor. Alas, it didn't even stay like that for very long...

To test the slave cylinder movement, remove the slave from the bellhousing and check the movement, first without load. Then bolt a plate across the end of the slave cylinder that restricts the slave cylinder travel and try the pedal again. Don't go nuts with it; only push as hard as you would to work the clutch normally; any harder and something may break. If the pedal feels at all mushy then there is air in the system.

If all this checks out, you could try this; make up a plate to fit the slave cylinder mountings on the bellhousing, with a nut welded in the middle of it, to accept a long bolt. Use the long bolt to work the clutch arm, and measure how much throw you actually need to disengage the clutch properly. Compare this with the slave stroke that you get under load.

None of this stuff is rocket science; however if you don't do some diagnosis of this sort, all that will happen is that the whole thing will get torn down (again, at vast cost of time and money no doubt) with no guarantee that the fault will be either identified or rectified.

cheers

mattv228 · Post by **mattv228** » Fri Dec 06, 2013 12:51 am

Brucey wrote:OK maybe there is something weird going on. Some ideas;

- is the clutch pedal hitting a stop of any kind? If it is, the compensation port in the MC may not open fully and this will make the clutch impossible to bleed properly.

- is the clutch a matched set of parts?

- did the clutch come apart for inspection when the arm etc was replaced?

-are you sure the bore iszes of the MC and slave are correctly matched to one another?

In the simplest terms there are only two possibilities; either-

a) the slave cylinder isn't moving far enough when under load, or

b) the slave cylinder is moving but but the clutch isn't disengaging.

On the latter point I once had a clutch driven plate break up (the rivets failed and the damper springs escaped...) and the first sign all was not well was that the clutch didn't disengage until the pedal was on the floor. Alas, it didn't even stay like that for very long...

To test the slave cylinder movement, remove the slave from the bellhousing and check the movement, first without load. Then bolt a plate across the end of the slave cylinder that restricts the slave cylinder travel and try the pedal again. Don't go nuts with it; only push as hard as you would to work the clutch normally; any harder and something may break. If the pedal feels at all mushy then there is air in the system.

If all this checks out, you could try this; make up a plate to fit the slave cylinder mountings on the bellhousing, with a nut welded in the middle of it, to accept a long bolt. Use the long bolt to work the clutch arm, and measure how much throw you actually need to disengage the clutch properly. Compare this with the slave stroke that you get under load.

None of this stuff is rocket science; however if you don't do some diagnosis of this sort, all that will happen is that the whole thing will get torn down (again, at vast cost of time and money no doubt) with no guarantee that the fault will be either identified or rectified.

cheers

-clutch is not hitting any stop

-clutch did come apart to replace arm. he did it all at once. previous shop i has clutch installed at put throw out bearing on wrong side. when arrived to new shop that was quickly fixed along with whole system

- im not sure on match. the shop is very reliable shop and i would assume they matched

so im thinking slave cylinder isnt moving far enough. due to some times it perfectly fine and shift great then other time i get into the car it will be tough until i drive it a little.

Shuttleman · Post by **Shuttleman** » Fri Dec 06, 2013 3:03 am

I think I'd still give the release bearing lever a wiggle.

mattv228 · Post by **mattv228** » Fri Dec 06, 2013 3:09 am

Shuttleman wrote:I think I'd still give the release bearing lever a wiggle.

Maybe doing the IE brass clutch pin upgrade would maybe help?

Pod · Post by **Pod** » Fri Dec 06, 2013 10:49 am

Could the driven plate have been installed the wrong way around

monoi · Post by **monoi** » Fri Dec 06, 2013 10:59 am

If it works fine, then doesn't, I would be inclined to think it would be more a failed cylinder seal somewhere.

wattsmonkey · Post by **wattsmonkey** » Fri Dec 06, 2013 9:41 pm

I wonder if there are different lengths of pushrod on the slave cylinder: worth a (triple) check? I'm thinking M10/20/30 box differences.

I used a pressure bleeder on the slave cylinder with pushrod held firmly in place and removed from the bellhousing so it can be bled "upside down" when I had problems with bleeding.

This must be driving you nuts!