The new model offers different ranges it can go for pressure, from 10 to 32 bar. The older model had a shimmed relief valve.

The loop flushing shuttle spool is bigger (from .25″ to .375″). This part will not be interchangeable. And you cant add this part to units of older style end caps, that has the charge relief and loop flushing valve it will not be available as service parts. If you do need newer end caps, then use the new style charge relief valve and loop flushing parts ..will not work on the older models.

Charge pressure can increase or decrease at 78 PSI per turn CW or CCW. The new relief plug does stick out some from the motor end cap about .63″ from the shimmed one.

You can see dimensions in the picture of the difference.

If we can assist you with parts or repair of your 90/100cc or any model of 90 series …give us a call at 800-361-0068

sales@htsrepair.com