I have been having an issue with my clutch hydraulics on my MGF VVC 1.8 1998. Since i bought the car I have had issues with it not actuating the clutch enough. The first issue came down to a failing slave cylinder seal, common for this car, i replaced the seals and it worked well for a few months if i recall. Until once again i started finding air in the hydraulics again, i figured that i just didn't bleed the hydraulics well enough. I re-bled it and it worked again for about another few weeks at which point the system went from feeling very solid, to spongy and not disengaging the clutch properly in the time of a 20 min drive. I assumed the problem was the master cylinder seals and so I replaced them. Now once again, a little over a week later i can feel the clutch engagement point becoming lower than usual and the pedal regaining that horrible slight spongy feel.
I have checked all the lines for any leaks and the are none that I can see. Since the slave cylinder seal replacement i have also had no evidence of
leakage on the opposite sides of the slave or master seals. (i.e. no fluid found around on the inside of the slave or master cylinder boots) I did find however that even though i had completely removed cleaned and replenished the whole hydraulic system with fresh fluid, the fluid in the reservoir is a bit dirty. My next move is to completely replace the master cylinder assembly unless anyone has a better idea! I think that the dirtiness of the fluid might be from the master cylinder bore being slightly rough and abrading away at the seals? (even though when i check the bore it seemed absolutely immaculate!)
Any ideas would be much appreciated
Also does anyone know if the clutch damper on the master cylinder is necessary? It means that there are two high spots past the master cylinder upper union making it very hard to bleed with out a high flow rate (the air bubbles will constantly rise to them). I may buy a proper vaccum bleeder, but i doubt this is the issue for this ongoing problem, i have had the clutch feeling awesome in the past using the 'Depress, open, close and release' bleed method.
