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MG Midget and Sprite Technical - Clutch Slave travel
|I have a 73 midget. New clutch kit installed and spent considerable time bleeding the line with both slave and master having new rubbers. there is good pressure on the pedal and the slave moves the lever to actuate the clutch however the clutch does not engage. My question is, how far should the slave piston travel? Or did I do something else wrong?|
Do you mean that it does not disengage? It never stops turning the input shaft? I just went through this on Seth's 74 Midget. We put my spare transmission into there, buttoned it back up and the clutch never completely let go of the disk. Ended up ripping it all back out of there and putting the fork from his original transmission into the spare. Travel of the slave was not affected, but the actual distance the throwout moved was. There is probably a little too much play in one of the fork bushings.
David "sorry, but you will probably need to yank that lump again" Lieb
|There's been several in the archives recently like this. seems a combination of new components dont always put the movement where you needed. I made an adjustable slave push rod to fix mine.|
|Dean Smith ('73 RWA)|
|Check for wear in pedal to master pushrod (both pedal and rod hole), slave pushrod hole, all clevis pins - amazing how much movement is lost due to wear in these parts.|
Recheck bleeding - try this link
Worked well for me.
|It's also worth knowing that you can get longer clutch pushrod - it's the mini version Part Ref: 13H396 and it's 90mm long as opposed to the original which I think is about 75mm. |
My Sprite was already fitted with the longer one - caused a bit of confusion when I ordered a new one and it was shorter!
|Harvey '71 Sprite|
|having changed the slave and master cylinders and spent ages bleeding, someone on this forum suggested the rubber hose that connects the two might be worth replacing, yep if only I'd replaced that first! although it looked in good condition, it must have been expanding under pressure, just a thought.|
|Need to be careful with longer pushrods - its ever so easy to bend the fork arm by over extending the stroke.|
The original set up works well if in good condition + need to check carbon bearings supplied are correct to ones being replaced, as there appear to be some incorrect ones also being supplied.
|The other point to bear in mind is that a longer pushrod will not increase the travel. It alters the section of the slave that the piston operates on. It is useful if the slave piston is contacting the end circlip, or to take up wear in the pivot points "downstream" of the slave, but be careful! |
As well as damaging the fork, it can also result in overthrow of the clutch, which damages the fingers of the pressure plate.
|According to Peter Caldwell: |
Measuring from the center of the bearing pivot to the face of the carbon
948 are .5"
1098 are .75"
1275 are .970"
Presumably this applies to new units.
Hard to believe that it is easy to bend the fork. At least the fork in the ribcase I was dealing with looked forged and had no discernible give to it. Hydraulics can certainly be powerful, however. Apparently, all it takes is a bit of wear to the pivot bushing for it to lose enough effective travel of the carbon.
David "there was a little girl who had a little curl, right in the middle of her forehead. And when she was good she was very very good, but when she was bad she was horrid... kinda like Spridget clutches" Lieb
When I'm next in thw workshop I'll photograph a bent fork - together with the bodged extended pushrod my wreck had when I bought it.
This thread was discussed between 20/04/2010 and 21/04/2010
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.