Light clutch pedal

A

andy_tt

Member
That is an idea, but I would prefer to fit a clevis that's made to fit. Everything I do is easily reversible if It should be put back to original. Hopefully will get an answer Monday and they sell the master cylinder too so will order both together
 
E

Eng1

Member
The slave cylinder is 3/4 “ and as a guess moves about 2”
The master original is 5/8 (0.625) the new is 1/2” (0.5) so .625/0.5 gives a ratio of 1.25
Ie the new master has to move 1.25 x the distance of the original master to move the same amount of fluid and give the same clutch movement
The slave seal should be fine as despite the piston having more force the seal loading is limited as the clutch moves .
There will be some extra movement of the slave available as the clutch disengages before the end of travel of the slave piston and the master has adjustment for pedal positioning to set the bite point .
Hopefully all the stars align and you have a super light clutch , you never know until you try !!
 
A

andy_tt

Member
That's it. I've got to try. I'm just trying to find a way of using the original reservoir, but it's a 1/2 hose and need to go down to 7/16 fittings and only a limited distance between the 2. I'm hoping I can get away with a braided line going to the slave. Thanks for your help and ideas
 
A

andy_tt

Member
Just an update.

Fitted the new master cylinder and it doesn't work. Don't seem to have enough movement of the slave to disengage the clutch.
So will have to put it back to original and maybe sell it
 
E

Eng1

Member
The movement you have is it easier ? You can remove the slave piston and insert a tube with the same OD , then use a smaller piston in the ID .
That would increase the travel for the same amount of fluid moved .
 
A

andy_tt

Member
It did feel lighter but I think that was just taking up all the free play. I started looking at removing the slack between slave and fork. Is this the right slave rod? Looks like a chopped up bolt. I've fitted nuts on it so the nuts sit on the edge of the piston and adjusted. It now works but I'm sure the release bearing must be applying pressure to the pressure plate as it was a bigger to fit.
The pedal is not massively lighter. It's also creaking and not smooth to operate now.

DSC_0635.JPG
 
E

Eng1

Member
www.ebay.co.uk

Nissan 30620-80E0A OEM Clutch Slave Cylinder SR20DET GTiR Pulsar RNN14 N14 JDM | eBay

Find many great new & used options and get the best deals for Nissan 30620-80E0A OEM Clutch Slave Cylinder SR20DET GTiR Pulsar RNN14 N14 JDM at the best online prices at eBay! Free delivery for many products.
www.ebay.co.uk
Should look like this ?
Yours don’t look right to me , creaking sounds like it is having a massive load on it , it is pointing to something wrong at the slave / clutch actuation fork or the clutch itself - somehow wrongly installed , wrong plate or bearing - it should not be that hard to operate
 
A

andy_tt

Member
The slave looks like that. The rod just didn't look right. I think it's just to much load for the master. It' was fine till I adjusted the rod is out of alignment as it's adjusted to the end of the rod to make it work. The fork moves . The little slack there is, you can see it's not seized
 
E

Eng1

Member
Just checked my car , new master line and slave , clutch uprated and done less than 500 miles -
Not that much effort to push the pedal , just using a prybar on the fork I can move it 1/4 inch with about
10 lb force - I’ll try to measure the pedal force
 
E

Eng1

Member
I would estimate around 30lb max and probably less than that maybe 24 or so (I do these sort of checks for force ,loads of times at work)
Google gives 20-30 lb as a normal car figure I checked after I tried it and estimated .
What is your guesstimate of the force (think lifting bag of cement with your leg )
 
A

andy_tt

Member
I maybe get a 1/4 inch before it gets too hard to move. I don't want to use to much force as I'm going against the thermostat housing. It's got to be a heavy clutch cover causing it
 
A

andy_tt

Member
I have no idea how to estimate force. My leg strength isn't average so it's not a good guide. Do you work with hydraulics?
 
E

Eng1

Member
Try pushing a weighing scale , not standing on it , but push the scale til you get to 30 lb or 12kg with one leg , that will give you an idea of the force from your leg
 
You must log in or register to reply here.
Top