Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Bleeding Clutch (broke again)

After my recent drama with the clutch (see broke again) I finally got time to work on the car.

1. Checked the master cylinder no obvious problems.
2. Checked the slave cylinder and found that the front dust boot had fallen off, cleaned off actuating rod and refitted boot.
3. attempted to bleed slave cylinder using the following tried and tested method; pump pedal hold down and slowly release bleed nipple.

Done all of the above, however no air or fluid comes out of the nipple, I taken the nipple off, just to check for debris, nothing its as clean as a whistle. Repeated the process still nothing, no fluid no air (the clutch works fine, no problems selecting gear). Bled the master cylinder from top union (no air present).

Can any one please explain why I cant bleed the slave cylinder from the bleed nipple.


Les Lewis


Did you actually take off the slave or/and the master, dismantle it, cleaned it and put it back together? If not, you may need to check the rubber seals are Ok as that is what will hold pressure in the slave/master.


Forgot to add,
Here is some interesting reading.



I checked the master cylinder first absolutely no leak, I then followed the normal procedures for the slave cylinder, although the dust boot had come adrift from the front there was no sign of any leaks what so ever. With this in mind I cleaned the actuating rod and replaced the dust boot. After this I attempted to bleed the system as discussed previously. Its the fact that I can remove the bleed screw completely with no detrimental effects to the hydraulics that is confusing me.
In short slacken off union on the master cylinder, no air but fluid under pressure, move to slave cylinder slacken off bleed nut in the normal manner, no air or fluid escapes, remove bleed screw completely, in theory fluid should pour out and clutch should not work, but the opposite is happening, and the clutch functions perfectly; in fact itís the best its ever been.

Iím now totally confused.

HELP !!!!!
Les Lewis

As an after thought
The rational explanation I can think off is that the slave cylinder has an internal diaphragm fitted, but none of the drawings I have show this. Iím loathed to remove the offending item in case I cant bleed the system when I refit it.

Les Lewis

Something is blocked somewhere. Sounds like crap in the internal entry of the bleed nipple. Take it all apart, it's the only way. It may just need cleaning, lubricate the seal and re-assemble. I bled by gravity, no problem at all. (might take a little longer, but painless)
Jerry Herbert

Les, it is very easy to take apart (and put together) the slave cylinder because it is such a simple device. Spring, piston, seal, etc etc. Do it, check and clean everything. Use compresssed air all over and check for scoring of the bore. Check the all the passages. Once you do that, you will know all about the slave and be confident if it is at fualt or not.


This thread was discussed between 07/08/2006 and 10/08/2006

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.