I was wondering if I can get you opinion(s) on a odd clutch problem that I'm experiencing.
New E153 transmission (MT90 fluid to level), new (single port) slave cylinder, master cylinder is about 4 years old. New derlin bushings (I have and have also tried the spherical bearing bushings as well). The clutch is 8puk ceramic – so it doesn’t allow for a lot of slip but not as grippy as a 4 puk per se.
When the car is cold shifting up and down is as smooth as it gets - no issues whatsoever. Once I've been driving for say half an hour or so I start having a little bit of trouble getting into gear (sometimes 2nd / 3rd sometimes all of them) and sometimes if i'm at the traffic lights after staring to roll in first - I have had trouble disengaging from fist to go into second (kind of had to force the lever out of first). I have had couple of instances where the thing just doesn’t want to get into any gear at all (despite pressing/releasing the clutch multiple times) and when eventually I get it into gear has no issues changing afterwards
This by all means doesn't necessarily continue happening once the car is warm - it's at best intermittent. It will occur sometimes and at other times there’s no issues whatsoever and shifts just fine. One other thing I noticed driving into a petrol station the other day – with the clutch fully depressed I felt a bit of bite from the engine similar as to holding the clutch in half way – which I think points to the hydraulics
I have not had any leaks from the master or slave cylinders. Bushings etc. are all new on the gearbox, shift cables are fine as well, clutch clevis pin is new. I have bled the system 4-5 times already – no bubbles.
What I’m trying to ascertain if the clutch master cylinder may be at fault. Previously when I had a bad master cylinder – it leaked inside the cabin but worked fine . This one albeit not new is only few years old and has no leaks (but it’s had moderately hard life pushing a 3000lbs pressure plate) and has not given me any trouble previously. It feels OK – it doesn’t get soft or spongy as such. Though why would master cylinder work OK when the car is cold and playing up when warm - I don't think the front part of the car heats up sufficiently to cause the master cylinder to play up.
Is it possible for just the front seal to leak on a master cylinder and effectively not allow for full opening of the slave at the back? Since I don’t have a leak in the cabin I doubt it’s the rear seal. No leaks in the trunk area either and fluid is clear and at level. A smidge of black stuff in the bottom of the fluid tank – which may be an indication that seals are gone/going but overall it’s clean.
I’ve ordered a rebuild kit ($25) since Toyota and supercheap quoted me ~$500 for a new master cylinder
– but if this doesn’t fix it I’m wondering what other avenues do I explore. Could a brand new slave cylinder be faulty (though there’s no leaks) ? Should I go and swap both cylinders and the hard line as well ? … it’s getting annoying since because of this I missed the 18th July run ☹
. So all OEM
) and now I don't dare touch the gear knob for anything else but changing gears, let alone thinking about going above 3000rpm 
