No resistance from the clutch pedal

[Spetz]

Hi guys,

Car is a 2001 Mitsubishi Mirage.
Stock clutch master cylinder.
The transmission is a mix of about 3 transmissions put together so unsure what clutch slave is on it.

What happened:
I took off the clutch master and clutch slave (I am prepping the car to get it onto a circuit so checking over a few things).
I cleaned both master and slave with brake clean (not sure if this is a bad idea?
I installed everything back and tried to bleed the system however pressing the clutch does nothing - There is no resistance and the fluid doesn't go down.

I eventually used a little siphon type pump to get fluid though the bleed nipple on the slave so there is fluid in the line (not sure whether there is also lots of air though) but the clutch pedal still has no resistance.


My thoughts are either the clutch master has completely failed but unsure how since it was working before removing it or that there? Could it be the brake cleaner and/or going dry? It sat without fluid for a couple of months.

Or I am unable to bleed it properly - But as mentioned I siphoned some fluid into the line so by now depressing the pedal should allow me to bleed it?


What can I do to test what is wrong?

 

[Silk]

Clutches can be a pain to bleed. I'd reverse bleed it - big horse syringe of fluid from slave to master.

 

[Ducked]

Might be air. I don't now have a hydraulic clutch but reverse-bleeding with a syringe works very well on the brakes.

However, I do think brake cleaner was probably a bad idea here, if you mean internally. They are (have to be) fairly aggressive organic solvents and I doubt its safe to assume they are all friendly with all rubber.

(I doubt there are many situations where brake cleaner is a good idea, but that's another discussion)

Also, if its an oldish and/or neglected system there might be corrosion ridges in the MC. Unusually large pedal movements might then destroy seals though in that scenario you'd expect initial resistance, declining rapidly.

 

[mk378]

+1 you've probably ruined the rubber piston seals in the master. Brake cleaner is only for brake pads and metal parts.

A good cautionary tale of fixing something that isn't broken.

 

[eljefino]

Stick your finger in the tranny's slave hole and see if the lever inside is there and has firm resistance.

I think you gorked your seals with the brake cleaner as well.

If the replacement tranny's slave has a radically different geometry, fluid wise, it won't work. Did it ever work in this config?

 

[Spetz]

Thanks everyone for responding.

So it turned out to be 2 things:
1. I wasn't bleeding it correct, I used a syringe to pull the fluid through and that worked
2. The banjo fitting on the clutch slave cylinder wasn't tight enough it must've been getting air in.

It's now working fine