25 replies to this topic

[tiger99]

No, if there is free movement BEFORE the pushrod, it is the clevis pin, or a very badly worn hole in the pedal, nothing to do with the hydraulics.

[Dan]

Did this start suddenly? The end hasn't snapped off the pedal shaft has it?

[booton]

this has happened suddenly. all parts of the pedal as they should be.

I know there is a bit of play in the pedal but i don;t think this is the main problem. 

 

tried bleeding the clutch today and with the bleed nipple open when pressing the clutch down it says on the floor will not return at all. 

returns 1/3-1/2 way with the bleed nipple closed. 

i manually have to pull the pedal back to pull the push rod all the way back. 

[Gremlin]

this has happened suddenly. all parts of the pedal as they should be.
I know there is a bit of play in the pedal but i don;t think this is the main problem. 
 
tried bleeding the clutch today and with the bleed nipple open when pressing the clutch down it says on the floor will not return at all. 
returns 1/3-1/2 way with the bleed nipple closed. 
i manually have to pull the pedal back to pull the push rod all the way back. 

Is the ball on the pivot arm worn badly, if so surely it would not return the pedal all the way but the clutch would fully engage anyway?

[booton]

no not badly i would say 1m either side. 

it can;t be this as the clutch pedal would not return when the bleed nipple was open. 

[Gremlin]

I can't remember how strong the clutch spring was on the pedal box when I changed mine but I would've thought that it is the diaphragm springs that do mist of the work, so if when you take your foot off the clutch, the lever arm is not pushing the diaphragm I would not worry too much about it, just make sure nothing is catching or badly worn and there's no leaks

[tiger99]

That is completely incorrect. The pedal return spring MUST push the pedal back FULLY so that the piston seal uncovers the reservoir port, so the volume of hydraulic fluid can vary with changes in temperature, minor fluid leakage, etc. The clutch diaphragm spring DOES NOT necessarily push the master cylinder piston back all the way. In fact, in the normal condition, foot off pedal, it is not pushing at all. As I have said here before on numerous occasions, it is essential that ALL Mini clutch and brake master cylinders have proper pedal return springs. On servo brake models, the brake return spring is in the servo, on all others a one-piece spring fulfils both functions, and if it breaks, the clutch, or brakes, or both, depending where it breaks, will have serious problems.

 

I think that the description of the problem is still not clear. There is wear in the pedal. How much?

[booton]

Problem righted it self. Strange one.

thanks fir the advice though.
joys of using a classic daily.

[ado15]

Dodgy flexy hose? The bore can collapse causing a blockage. This might account for the pedal not returning even with the slave bleed screw open.

[tiger99]

It should still return. The pedal return spring is strong enough to create a vacuum in the hydraulics. Remember that the only opposing pressure is atmospheric, about 14.7 psi, acting on the small piston area of the master cylinder, so only a few lbs pressure.

[ado15]

Actually, thinking about it a bit more, the master cylinder pushrod isn't attached to the piston anyway. So it would return on the pedal spring leaving the piston behind if the hose was blocked. It would then only be the spring in the master pushing it back.