Reel keeps 'slipping'

I have a Penn Senator 3/0 reel but when i get a good fish on the reel it starts to strain and 'slip'. Anyone know what the problem is or should I send it off for repair??

are you sure the lines well tied to the spool ,i've seen braid slipping around the spool and not small amounts ,we're talking 300m !
Also could be your clutch disc's is contaminated with either water or oil/grease ,easy enough fixed just take out the washers and give then a good degrease and dry them out well before replacing .

It's not the line slipping cause I was using the same line at the start of the year and it was fine. Think I will have to open it up and have a look inside.

It's not the line slipping cause I was using the same line at the start of the year and it was fine. Think I will have to open it up and have a look inside.

I'm not entirely sure what the problem is- if the clutch is set correctly a good fish should be able to take some line if it applies enough pressure.

Is it slipping gears? Is it accompanied by a bit of a grating noise? If so it could be worn gearing. Although I have seen in the past, not on a Senator right enough, that when maybe the casing screws arent tight enough it leaves a bit of play which can cause gears to slip. Also seen it happen if the knob that controls spool float is left too loose.

Yes the slipping is accompanied by a grating noise, I have caught 50 pound tope with this reel before but it seems to be worn now??

my money would be on the star drag needing tightened (it probably doesn't as by the sound of it its doing its job!) but lots of people hate a clutch that lets out line!!!!