Movement of clutch master cylinder when clutch is activated

[Ian1986WP]

I've had this issue on my Isuzu KB 280 D and had the firewall repaired and reinforced with two 3mm plates to stop the "play"

[waterwart]

The firewall might be cracked as to why it is flexing like that. I read about it on hotroder.com. Just put it in the search box.

[claywillcrow]

I have a 1988 f150 and i was experiencing the same problem. Check underneath the M.C (master cylinder) to see if it's leaking fluid when you pump the clutch. it may be cracked at the base or the firewall is cracked where the M.C is attached. Eventually my M.C completly broke. Now I have a new project on my hands.

[kklein41291]

it aint bolted down all the way, check alll the bolts and nuts a so forth

[artfd]

To any interested mechanics, does this look like "oil-canning" of the sheet metal of the firewall? I've read about this problem, but have never seen it for myself.