help Transmission Sluggish??! 96 Golf

Hi,

I just got this car and Im used to manual transmisssion so I thought it was normal that a 96 golf would not immediately change gears on a slope.

The engine seems to rev up past 300 rpm on a slope before changing gears, is that normal? Please help... I am planning on doing a transmission flush, does anyone know if that would help or what the problem could be.

A little more to help diagnose the problem:

When I am on a very gentle slope starting of (1st gear) and I press on the gas gently it goes up to 300 rpm and usually doesnt change unless i release the gas peddle. Please help.

Thanks,
Marshall