Low clutch pedal

[Davemate]

Ok what causes a low biting point on a clutch ?

I have fitted
A new release bearing
New bronze bushes,new tolerance ring and a new piviot pin.
A new slave cylinder to arm rod and piviot pin have been fitted as well.
New seals have been fitted to the master cylinder,and I have fitted a new/second hand slave cylinder to which I put a new seal in.
The clutch was my old one put back in which has plenty of meat still on the friction plate.
Before I put all the new bits in I would have said that the biting point was a bit higher but I can't be sure. With all the new pins and bushes fitted all/any play has been removed so I thought the biting point would be at a more noticable higher point. All the old pins and rods were worn quite badly.
The master cylinder is a standard 1200 herald,the slave is the one with a grove only down one side.
It's all fitted to a 1500 engine and single rail box.
I have 3 or 4 " of free play at the top of the pedal travel is this normal ?

[Velocita Rosso]

OK Dave...the problem can be solved quite easy
Take the slave from the clamp on the housing and you will see a recess in the slave where the pinch bolt goes through
Get an angle grinder and grind another 1/2" of meat off the length of the recess eg so it makes that recess longer on the rear end
This will allow you to move the slave further forward ,which in turn takes up more slack on the push rod
Once done you will notice a heck of a difference
I did this on mine and proved very succesful
See you at Bovingdon..............when you pick up another tenner ;)

[Davemate]

Mike
I would just make a longer rod but I dont fancy pulling the box out again to fit
I may well give the old rod to the engineer at work and ask him to get a solid peice of bar and drill one end to take the origanal rod and turn the other end down to the same diameter as the rod so I end up with a sleaved extension
I must admit your way does seem nice and simple !
How about putting a solid slug into the slave cylinder between the piston and rod

And yes I'll see you at bovinton as I will be carrying out timing duties again

[roddymacp]

I too had this lw biting point and free pedal travel. When I discnnected the pedal from the master ylinder, I saw that there was free movement in the cylinder push rod. Turned out that the spring in the ylinder was broken, so on releasing the pedal, the piston did not return fully to the end of the cylinder. Therefore I only had 3/4 of the master cylinder activation. A new spring from an old cylinder fixed it and brought all movements and biting point back to normal. Check that spring. It's a lot easier than a slave mod.

[Velocita Rosso]

1344 wrote:

Mike
I would just make a longer rod but I dont fancy pulling the box out again to fit
I may well give the old rod to the engineer at work and ask him to get a solid peice of bar and drill one end to take the origanal rod and turn the other end down to the same diameter as the rod so I end up with a sleaved extension
I must admit your way does seem nice and simple !
How about putting a solid slug into the slave cylinder between the piston and rod

And yes I'll see you at bovinton as I will be carrying out timing duties again

Dave
You dont have to take the box out again, just the tunnel  and then remove the slave
It will take about half an hour to complete, by just grinding the slot longer.
Then you have the adjustment in your fingers when you slide the slave in and nip up
If you make a longer rod you may not know how long you want it
You dont want constant pressure on the rod/clutch or you will be needing another new clutch

[Davemate]

Mike
   Point taken, it's a job for during the week as I have a couple of exhaust joints leaking that need sorting first.
Do I just push the cylinder in a bit then try the pedal and then push a bit more until I am happy with the position or do just push the cylinder in until I feel resistance from the clutch then back off a wee bit.

[thebrookster]

Dave,

What are the holes like at the top of the clutch pedal arm, where it joins on to the master cylinder with the pivot pin? I had a similar problem with my last sportier, and it turned out that as the holes had worn there was a bit of play. It would appear that a small amount of wear here equates to surprisingly large amount of pedal travel, and movement of the biting point. I had to weld the hole up and redrill it in the end.

I only ask as I see you mention you had wear on parts of the system, so this could be a culprit!

Cheers,

Phil

[Davemate]

thebrookster wrote:

Dave,

What are the holes like at the top of the clutch pedal arm, where it joins on to the master cylinder with the pivot pin? I had a similar problem with my last sportier, and it turned out that as the holes had worn there was a bit of play. It would appear that a small amount of wear here equates to surprisingly large amount of pedal travel, and movement of the biting point. I had to weld the hole up and redrill it in the end.
I only ask as I see you mention you had wear on parts of the system, so this could be a culprit!
Cheers,
Phil

I'll have a look I did not think to check that,as said everything else has been renewed.
I know it's sound a bit numpty but I never really clocked were the biting point was I just drove the car.
It mayby the biting point is higher than it was,it just seems low now !

[Velocita Rosso]

1344 wrote:

Mike
   Point taken, it's a job for during the week as I have a couple of exhaust joints leaking that need sorting first.
Do I just push the cylinder in a bit then try the pedal and then push a bit more until I am happy with the position or do just push the cylinder in until I feel resistance from the clutch then back off a wee bit.

Just a step at a time, dont just do it one go,trial and error

[thescrapman]

Dave

When you say free play, is that movement of the pedal that is making the slave move and pushing the arm to relaese the clutch, or is it "free movment" where nothing is happening.

There are master cyl push rods about that are the wrong length, or it could be oval holes in top of pedal and in the pushrod.

Wrong bore clutch or slave cyl is another option.

Be wary of filing additional slots, certainly until all other optios are chacked, it might be perceived as a bodge to cover another issue.

Cheers

Colin

[Davemate]

Well I checked the master cylinder push rod - pledal pin for wear.
It does not look totally worn to me there is no step.
There was quit a bit of slack though so I replaced the pin with a larger one.
The clutch pedal now has very little "free play" and the biting point is now in a much higher and better place.
I then replaced the brake pin as well,my brake pedal now feels better as well !!
The washer in the pic are the ones from the pin just to show the slack play the new pin is a nice fit,not tight but nice.

So once again job done  :)

[ferny]

Have a chat with your engineer at work as he might be able to drill and bush your pedals as the hole the clevis pin goes in probably isn't round any more.

[Davemate]

Last night on the way to and from the plough the clutch still did not feel quite right.
Today I pulled the slave cylinder out bled it in an upright position just incase there was any air in it, which there wasnt and I made sure it was pushed right in and it was.
To bleed it I pumped the pedal slowly with the slave not in place so I now know the piston moves up the "stop point" I then opened the bleed nipple.
When I put it all back together again I put the slave into its holder then put the bolts in just a little and pushed the clutch pedal,that way as I tightened the two bolts I would know that the slave piston was being pushed back as I tightened them up.
The pedal now seems spot on and the biteing point seems half way down which to me seems bang on.
Not sure which of the above would have altered anything but something has !
I did notice I have a very slight weep on the slave cylinder so I may replace it and the copper pipe.
Not sure if the leak is from the bleed nipple or from the copper pipe,both look a bit manky.
I suspect it's from the copper pipe union as the pipe does not look quite central to me.

[sparky_spit]

Sounds like you have sorted it but if you ever feel like making the slave pushrod into the deluxe version, just make it adjustable for length.  This is a common mod on Minis to get the clutch bite just right in the pedal travel.

I've seen 2 versions; one with a threaded insert and locknut, and the other with a threaded sleeve that has a righthand thread in one end, and a lefthand thread in the other. This means you don't even have to disconnect it to adjust it; it works on the same principle as a yacht's rigging screw.

[Davemate]

I just arrived at work and the clutch feels good.
I know it's normaly the kiss of death but it does seem to be sorted,
Just the new smell of petrol when i booted it, to trace now !

[Tim Bancroft]

Dave,

Shame that you are not taking part in the autosolo.

[Davemate]

timbancroft61 wrote:

Dave,

Shame that you are not taking part in the autosolo.

Tim
Funds are very tight this year and I am doing the RBRR hence the empty pot !
I do enjoy marshalling at bovinton but next year I'll be doing as many auto solo's as posable  :)

Just think you get 18(if I worked that out correct) runs at bovinton.
18 adrenaline rushes, as a Marshall watching the clock I get over 100 rushes because I am always wishing and wanting you all to get faster times as you are all going around and remember I can see the clock,you can't !
If that makes sence !!!

[firebobby]

1344 wrote:

Tim
Funds are very tight this year and I am doing the RBRR hence the empty pot !
I do enjoy marshalling at bovinton but next year I'll be doing as many auto solo's as posable  :)

Just think you get 18(if I worked that out correct) runs at bovinton.
18 adrenaline rushes, as a Marshall watching the clock I get over 100 rushes because I am always wishing and wanting you all to get faster times as you are all going around and remember I can see the clock,you can't !
If that makes sence !!!

Dave, you will have to give me some marshalling on the marshalling mate ;)