307 Crank oil seal, Polyacrylate, Teflon?

[RustyUK]

Hello all,

I recently did a clutch change on a friend's old 1.4 petrol 307, flywheel skim, gearbox recon and various bushes etc, and naturally changed the rear crank seal as a precaution. Well, technically, I didn't do that one bit - I let him do it!

So it's all back together and after only one trip there's engine oil weeping from that area, so got to pull the whole lot apart again. I've changed these before without an issue, and while I didn't do that bit myself, it certainly looked like it had been carefully pushed home. Nothing visibly wrong before the flywheel went back on.

So what I've become aware of are modern PTFE (Teflon) seals exist, and I know those need special care and must be pushed on dry and left for a few hours. This seal was a Febi brand, and claims it's made from FPM / ACM (Polyacrylate). It was black not red, with a plastic protective thing in the middle. I didn't examine it properly but we believe unlike the traditional sort and the one that came off, it didn't have a spring, so I guess it falls into this category or something more 'modern' and apparently very delicate whatever it is.

I really can't find much info anywhere about Polyacrylate seals or special precautions. I know he did dab a bit of oil on to ease it on, which is a big no-no with PTFE ones. Does anyone know if this is likely to have ruined the material? Is this material akin to the delicate PTFE ones?