Been on with this a while now and here's where I'm at

Bear in mind that I have changed the clutch on a different zed a few times and previously had new slave cylinder and master cylinder less thank 10k ago in a different zed.

 

Bought a auto and want to turn into a manual

Put pedal in and adjusted to the correct position

The system was bled using the correct procedure including the nipple near the hicas, no luck soft pedal and slave only comes out a small amount 10/12 mm.

Made a one piece line straight from master to slave and filled from bottom using oil can, no luck soft pedal and slave only comes out a small amount 10/12 mm as before with no real pressure on fork.

Bought a new slave cylinder and filled from bottom as before and bled, still the same, looks a bit better watching from underneath, but pedal way too soft, doesn't seem to get firm until last 2 inch of downward travel (which has been story all along)

 

Cars not been running when bleeding.

Bleeding procedure used is filling from bottom the manually pressing the slave cylinder pin in and out until all small bubbles have risen out of filler bottle, then as the manual states 4 pumps of clutch pedal hold in and release nipple then repeat at the slave.

 

I'm about to order a master cylinder seal kit from the States but do I have a pedal or booster problem? because it's driving me mental :(

Does it get better with pumping?

The booster failing would cause it to be too heavy, not too soft. Check operation with the engine on and off.

Did you say you had a one piece clutch line? If not, invest in one. They can be a pig. Check behind the dash for fluid, often if the master has failed it leaks into the cabin.

I'm about to order a master cylinder seal kit from the States but do I have a pedal or booster problem? because it's driving me mental

 

Why dont you just buy a new cylinder to rule out any problem with your existing set up. They are only £35 ish....

 

No need to faff about trying to revive old tired components at that kind of money

 

http://www.ebay.com/itm/Clutch-Master-Cylinder-Dorman-CM39828-fits-90-91-Nissan-300ZX-/311232868493?fits=Model%3A300ZX&hash=item4876ecb08d&vxp=mtr

Yeah I know what you mean Pete, I didn't want to start throwing money at the problem due to all seals getting replaced 10k ago when a OS Giken clutch was installed (only for about 20miles) that's why I assumed they was OK.

 

I have a braided line to the slave, and a home made copper going from the braided connector to the master, no leaks I did have a concern about sucking air in at first but I'm pretty confident it's not.

It doesn't get firmer with pumping either.

http://www.ebay.com/itm/Clutch-Master-Cylinder-Dorman-CM39828-fits-90-91-Nissan-300ZX-/311232868493?fits=Model%3A300ZX&hash=item4876ecb08d&vxp=mtr

 

got one of these ordered should be here on tuesday

 

http://www.amazon.co.uk/gp/product/B00FAIJLPC/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A36OJLYJM7N41A

http://www.ebay.com/itm/Clutch-Master-Cylinder-Dorman-CM39828-fits-90-91-Nissan-300ZX-/311232868493?fits=Model%3A300ZX&hash=item4876ecb08d&vxp=mtr

 

got one of these ordered should be here on tuesday

 

http://www.amazon.co.uk/gp/product/B00FAIJLPC/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A36OJLYJM7N41A

 

Well thats even cheaper.:thumbup:

Putting new rubber seals in to old metal bores that have had lots of use and may be worn never seemed like a job I was going feel 100% confident with.

IMO everything needs to be 100% especially when we are asking the cylinders to exert a lot more pressure shifting aftermarket/stronger clutches

That's why there's a cry for help as everything is taken from my old car which was running fine, I didn't want to throw money at it replacing everything but I've started now lol.

Got to be better with the new hydraulics (fingers crossed)

 

p.s I got this slave and its a direct replacement

 

http://www.ebay.co.uk/itm/391132937681?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

£16 delivered

 

Just paid more for a McDonald's :/

Got to be better with the new hydraulics (fingers crossed)

Yep.

It rules them out as problem areas.

Likewise your new braided line.

http://www.ebay.com/itm/Clutch-Master-Cylinder-Dorman-CM39828-fits-90-91-Nissan-300ZX-/311232868493?fits=Model%3A300ZX&hash=item4876ecb08d&vxp=mtr

 

got one of these ordered should be here on tuesday

 

http://www.amazon.co.uk/gp/product/B00FAIJLPC/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A36OJLYJM7N41A

 

 

 

I replaced my master cylinder with that Jakoparts one from Amazon, in fact that's my review on Amazon. I can recommend!

 

The master cylinder turned out to be my soft pedal problem, couldn't even get my Zed into gear.

Edited July 17, 201510 yr by MasterCookieman

Well the hydraulics replaced, no joy, going to concentrate on the booster now :(

I'll keep the thread updated...

Well the hydraulics replaced, no joy, going to concentrate on the booster now :(

I'll keep the thread updated...

Just to throw some ideas in, could be talkin rubish, long time since i played with clutch pedals....

 

Are the switches under the pedal adjusted wrong and stopping movement, i remember when doing mine being told to adjust them out completely before doing any adjustments

 

I seem to remember there being adjustment between the pedal and the booster as well as adjustment between the booster and the master

 

My problem turned out to be i was adjusting it the wrong way, thinking i needed to add presure, but i actually needed to lenthen the stroke

Just to throw some ideas in, could be talkin rubish, long time since i played with clutch pedals....

 

Are the switches under the pedal adjusted wrong and stopping movement, i remember when doing mine being told to adjust them out completely before doing any adjustments

 

I seem to remember there being adjustment between the pedal and the booster as well as adjustment between the booster and the master

 

My problem turned out to be i was adjusting it the wrong way, thinking i needed to add presure, but i actually needed to lenthen the stroke

No bud, TT he switches are well out of the way and the stroke is on maximum. When the master cylinder is off and the pedal is pressed the push rod comes out of the booster in 2 stages and can be pulled out of the booster, bear in mind the cluch wasn't working at the time that's why I looked at this (I have a video). Don't think its right, need to have a Google research you can get booster rebuild kits not for a zed but for a patrol, I've going to have to gibe this a go.

No bud, TT he switches are well out of the way and the stroke is on maximum. When the master cylinder is off and the pedal is pressed the push rod comes out of the booster in 2 stages and can be pulled out of the booster, bear in mind the cluch wasn't working at the time that's why I looked at this (I have a video). Don't think its right, need to have a Google research you can get booster rebuild kits not for a zed but for a patrol, I've going to have to gibe this a go.

I have taken the booster out and inspected, put onto pedal assembly on bench and adjusted to get the full stroke of the pedal, I am getting now approx 28mm of stroke at the booster cylinder at the pedal side, I measured the master cylinder stroke and is 30mm.

Just reassembled and the pedal is better but not great, its stiff only after half way downward stroke, I'm going to get myself a 10mm longer pin at the slave cylinder as when the pedals on its first half of stoke its doing nothing and that's all I can think of, I don't know why it needs altering something must be amiss the pedal doesn't get better through pumping either.

 

I might be confused but I swear you can wind the pin out to make it longer.

I might be confused but I swear you can wind the pin out to make it longer.

 

Your right (pin coming out of booster),mines a bit rusted up though and because it forms a seal I didn't want to go mad with the grips to loosen it. I discarded that because according to the manual you can only get 0.5mm adjustment anyway.

Saying that in the manual it also states that the booster might be kaput if it need more adjustment, I thought it may have been OK when I put it back in due to the stroke measurements.

I did inspect the booster and there was no vac leaks and It did hold pressure when I capped off the pipe which goes to plenum.

Got a slave cylinder pin made up at work, came home and ground to the exact length (1mm play at fork), still no good.

Going to strip booster down one day this week to look for a reaction disc :/

The reaction disc had fallen out? put back in and rebuilt all, when I finally got sorted and was about to tighten up master cylinder the push rod had pulled out again, was not happy :(. anyway went ahead with test seemed better but sill about 20% free play on pedal travel. I swapped over the slave pin to a 5mm longer one as It would fit, (from my old slave to my new slave)

Does this look OK to anyone that would know?

 

 

I don't really want to take all apart again to check that the disc is still in place as I risk pulling the disc out again on inspection.

I don't really want to take all apart again to check that the disc is still in place as I risk pulling the disc out again on inspection.

Always a good idea to glue it in place.

I rebuild servos for the earlier zeds and alway glue it in place.