QuestionHi Howard,
Thank you for all your expert contributions here, as they have been invaluable to me, and I am sure, many others.
I have a 77 spitfire 1500 with 48000 miles, and I am curious about it's clutch high release point. Everyone seems to have trouble with clutch release at the floor. Mine is the opposite. I only need to push the clutch in about 1/3 of the travel to shift smoothly. It has started to release higher and higher, and now releases( and engages) just before the top of the pedal range, (just before it comes back out, fully at rest.) It doesn't really grab or anything strange, and I am NOT getting any surging, rpm revs or slipping, and seem to have no trouble with grinding, so I am wondering what this means. Also I can hear what sounds like springs popping and clicking as I depress the clutch. Certainly, something seems like it might be going, just no idea what.
Also, I did replace clutch slave and master cylinder, and currently still on dot 3 (I know). fluid has become a bit cloudy, but no leaks that I can see. Any Ideas?
Thanks so much.
Chris
AnswerHi Chris,
You have what everyone else wants and that is a high release point. It is odd and may be something wrong so here are several tests.
First note if there is any free play in the clutch pedal. It should have about a inch or more free play before you feel any hydraulic resistance.
Next, have someone pump the pedal a few times and note if the free play gets less. It should not. Then open the bleeder valve on the slave cylinder just quickly and close it (foot off of the pedal) This it to see if it is maintaining any pressure after the pedal is released. Fluid may dribble out but you should see no pressure come out of the bleeder valve.
If you only hear the "Clicking" when the pedal is close to the floor, avoid pushing the pedal all the way down as it may be damaging the clutch. If you feel anything in the pedal that is in sync with the clicking there is a problem and you should avoid pushing the pedal that far.
A good hydraulic system and a smooth straight spinning disk with a straight releasing pressure plate will release high and engage quick. A wobbling disk and pressure plate and wrongly designed hydraulic system will usually engage just off the floor and need the pedal pushed hard into the floor to change gears. (normal Spitfire and TR-6)
If the replacement master cylinder was a larger bore or the slave was a smaller bore that you installed that would account for the high release point. ( I use to do that on the TR-6 to correct the badly designed hydraulic system, but I have not researched the Spitfire to see if a different bore was available.)
Here is a good test for clutch slippage. Take the car out on a long straight road and run it up to 3500 RPM in 4th gear and hold the throttle steady at that speed and stab the clutch pedal down and release it quickly. This quick stab and release of the clutch will cause the RPM to climb momentarily and the car will jerk forward when the clutch is quickly released.
(if the clutch has a good grip)
If the car does not jerk and it acts like you may have just had a shift of an automatic transmission then you don't have a good engagement of the clutch. The longer and smoother the clutch grabs the worse the clutch is. The reason you need 3500 RPM is because that is about the max torque of most British engines and the reason it must be done in 4th gear is that the max load on a clutch is in 4th gear not low gear like most people think.
If that is ok and the noise is only close to the floor with the pedal, you might want to consider securing a small block on the floor under the pedal to prevent the clicking noise which could be doing damage but if restricted from doing so it may make the clutch last a long time before it is necessary to go inside.
If you find out what caused the high engagement let me know as I would have loved to know that years ago when I use to get so many complaints from Spitfire customers. I still get a few on this program too.
Howard
