Re: clutch disfunction

[C2slayman@xxxxxxx]

Hey Modelle,


> Date: Mon, 21 Jul 2003 08:23:06 EDT
> From: GModelle@domain.elided
> Subject: clutch disfunction
> 
> Esteemed Digesti,
> Yesterday I renewed the GTV clutch master cylinder, hoping to solve a clutch 
> 
> problem that I'm beginning to think might be a reassembly mistake. With the 

Maybe.  It's been a while since I looked at the guts of the clutch master 
cylinder.  So I forget if there is a check valve or bypass port that allows fluid 
to be drawn from the reservoir and returned to it.

> newly rebuilt engine having only recently been dropped into my ongoing 
> restoration, the clutch pedal does not begin actuate the clutch spring until 
> about 
> two-thirds of the way down it's stroke. The clutch lever arm seems to have 
> the 

That's strange.  The hydraulics are self-adjusting.  The spring in the slave 
cylinder is supposed to expand until the rod contacts the yoke which contacts 
the throw-out bearing which contacts the rockford spring (whew!)  Hence, zero 
clearance.  As I recall, there is also a spring in the master cylinder to do 
the same thing on the pedal side of the circuit.  When you step on the pedal, 
you should get immediate engagement of the throw-out bearing.  But the clutch 
won't disengage until you get more travel.  First check that the slave cylinder 
is expanding completely to meet the fork before the pedal is stepped on.

Then with an assistant compressing the pedal slightly (only a few mm), 
confirm that the slave cylinder is moving.  I believe the spec for total slave 
cylinder travel is ~12mm.  I forget what the spec is for total master cylinder 
travel.  Check in the manual.  Otherwise, I can measure my Spider.

> proper angle as it emerges out of the bell housing, but as it's installed, 
> I can 
> manually move the lever against the slave cylinder, compressing it into it's 
> 
> bore. My other 105 slave is tight against the clutch spring in the retracted 
> 

Hmmm..... I can compress my '89 slave cylinder back into its bore by hand and 
it's OK.  I believe that's because I'm just pushing fluid past the check 
reservior port.  But once you step on the pedal, that port is closed off and the 
only place for the fluid to flow is from the master to the slave cylinder.  By 
the way, the slave immediately expands back to engage the pressure plate 
spring

If you push on the clutch pedal by hand, do you feel resistance immedialtely? 
 If not, then there is wasted travel in the pedal that is not doing work to 
disengage the pressure plate - maybe it's the master cylinder piston push fluid 
up into the reservoir port instead of into the slave cylinder.  Do you recall 
what the whole rebuild assembly looked like?  Do you recall seeing the 
reservior port?  Is it possible that the master cylinder piston is in backward?  (Or 
did the rebuild kit come with a new piston?)

> position. Something is definitely amiss. The GTV has a later-model EFI 
> bell-housing...is it possible that the clutch geometry is different on these 
> later 
> cars?  Is it possible that the slave cylinders have different mounting 
> arrangements? Any advice would be GREATLY appreciated. 
> modelle in somers point
> 105's 1 & 2
> 

I don't recall any major differences between my 74 and 89 Spiders.  But I'll 
let those more expert in the parts numbers comment on that.  Again, I would 
check for ~12mm slave cylinder travel to determine  if the problem lies within 
the clutch assembly (if you are getting the full 12mm slave cylinder travel) or 
if it is in the hydraulic linkage (if you are not getting the full 12mm 
travel).

Good Luck!
Charlie
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