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clutch woes
- Thread starter Limey
- Start date
Limey
Donation Time
Attachments
Limey
Donation Time
Never seen a bent one. Anybody else seen one like this?
It actually looks like it bends away from the slave doesn't it?
Oliver
Limey
Donation Time
My pedal has two holes just like the brake pedal. Once I moved the clevis to the hole nearest to the fire wall I have good pressure after 1'' of travel.
Which hole is best?
Oliver
Limey
Donation Time
This is for all you maths guys out there
I went on a maths site to see if a 3/4'' bore slave will do the job by increasing slave piston travel from 1/4'' (7mm) to 1/2'' (12.5mm)
At present my 1'' slave moved the piston along the bore 7mm (1/4'') R12.5mm (25mm dia. bore) x 7mm travel gives a fluid volume of 3436
Therefore - if I have a fixed volume 3436 delivered by the MC and want 1/2'' travel (height) I need a bore radius of 9.37mm=18.74dia = .73'' = 3/4'' bore
I really must get out more...
I still don't know why I have the problem but at least I have the solution
Oliver
I went on a maths site to see if a 3/4'' bore slave will do the job by increasing slave piston travel from 1/4'' (7mm) to 1/2'' (12.5mm)
At present my 1'' slave moved the piston along the bore 7mm (1/4'') R12.5mm (25mm dia. bore) x 7mm travel gives a fluid volume of 3436
Therefore - if I have a fixed volume 3436 delivered by the MC and want 1/2'' travel (height) I need a bore radius of 9.37mm=18.74dia = .73'' = 3/4'' bore
I really must get out more...
I still don't know why I have the problem but at least I have the solution
Oliver
bernd_st
Bronze Level Sponsor
Wow lots of nowadays scarce NOS bits. I' m only keeping some old rotten and crusty bits here and there 
Several comments:
a) The lever is not bent but an original S2 one
b) The bend goes towards the slave. If yours is straight it sounds like wrong
c) Impressed by your maths. But what's missing in your equation is the force to operate the clutch which will drastically increase once you increase the MC diameter
Several comments:
a) The lever is not bent but an original S2 one
b) The bend goes towards the slave. If yours is straight it sounds like wrong
c) Impressed by your maths. But what's missing in your equation is the force to operate the clutch which will drastically increase once you increase the MC diameter
Limey
Donation Time
Hi Bernd_st.Wow lots of nowadays scarce NOS bits. I' m only keeping some old rotten and crusty bits here and there
Several comments:
a) The lever is not bent but an original S2 one
b) The bend goes towards the slave. If yours is straight it sounds like wrong
c) Impressed by your maths. But what's missing in your equation is the force to operate the clutch which will drastically increase once you increase the MC diameter
The maths was online and I only had to drop in the figures. I'm no good at 'full' maths
I have 31 boxes in total
10 years of collecting on ebay for the rebuildI have factored in a harder clutch but its not much of a push and I'm only considering changing the slave not the Master.
I have three levers and all are straight including the one I took off for the rebuild. If anybody out there has a non straight fork let me know
either way this wouldn't cause my problem of only 7mm travel at the fork outer end
If my master and slave bores are correct then perhaps either the MC rod is too long (reduced stroke) or the MC is faulty in some way and the displaced volume from it is too little due to bad/wrong seals but it's a NOS unit with new seals and a clean bore and the pedal has full travel suggesting that the rod is correct
Oliver
65beam
Donation Time
The slave push rod that was on my red Harrington is an adjustable piece. I removed the trans from it after the wife bought our current project. It seems that while we were gone on a weekend that the kid decided to put the non syncro trans into first gear while moving. Trashed the gear. We rebuilt the trans and OD for the project. Here's a photo but it's hard to see.
bernd_st
Bronze Level Sponsor
Noted. It may puzzle you but just checked my stocks and all early series clutch forks I have (3pcs. in total) show the same bend as the one in the picture. Are you sure you have a proper early Alpine one ?
On the other hand 7mm travel on the outside sounds to less despite it translates into more on the actuating side of the lever...
On the other hand 7mm travel on the outside sounds to less despite it translates into more on the actuating side of the lever...
Limey
Donation Time
Hi - I am puzzled certainly. I will dig out my 3 out of deep store and check. The photos I took are not at the best angle to see a bend or not
The adjustables were only used on S1s because they had short body slaves. SII-SV had long body slaves and non adjustable rods
Anybody out there confirm 'bent' forks as per Bernd_st picture?
Oliver
65beam
Donation Time
Oli,
With the problems you're having you could have changed out the rod to either a longer one or an adjustable one and the car would be ready for use. There were reasons for these items to be sold. This is what came off the red Harrington and the push rod was part of this unit. Disregard the date on the photo. I took these photos yesterday. The camera has it's own mind.
With the problems you're having you could have changed out the rod to either a longer one or an adjustable one and the car would be ready for use. There were reasons for these items to be sold. This is what came off the red Harrington and the push rod was part of this unit. Disregard the date on the photo. I took these photos yesterday. The camera has it's own mind.
jfcroni
Donation Time
I use the hole closest to the FW. Whichever gives you the best result.
Limey
Donation Time
Thanks 65beam - I'll check for the fork offset now
Just to be clear rod length at the slave is NOT the problem. Slave piston travel is the problem; 1/4'' movement when it should be 1/2''. A bent or straight fork or a long or short slave rod would make no difference. I tested last night with a 6'' slave rod I had lying around which only just fits, with the slave piston pushed right down the bore and no difference...
Everything is pointing to the MC but everything there is NOS/rebuilt and seemingly correct but I will check the MC rod length, function and travel. Maybe not enough fluid is getting pumped to the slave. It's the last test I can do but it makes no sense.
What did Sherlock Holmes say - ''When you have eliminated the impossible, whatever remains, however improbable, must be the truth
Cheers
Oliver
Limey
Donation Time
Could I ask you a favour? Could you measure from the center of the clevis hole to the pedestal fulcrum centre?
It's a long shot but it would be good to eliminate it from enquiries....
Oliver, I have no faith in NOS parts. I've been burned several times with them. I think a lot of the NOS was found to be defective when new and when returned, simply put back on the shelf. That has really made me hesitate to replace working parts, regardless of circumstance. I certainly never assume that new or rebuilt parts are good. That is a good way to drive yourself crazy.
Bill
Bill
Limey
Donation Time
I've checked and my arm has a slight kink as well. Did these straighten on the later series or were all series kinked? Thanks to everyone for the pics.
Oliver