Neville Gary Jones, 48, had been drinking with his 27-year-old son Jamie and another man at the Kingswood Pub when the father and son argued over money.

The row continued on their car trip home. As the car stopped in Cambridge Park, the accused allegedly picked up a hammer from the floor and swung at his son, striking him on the left side of his head. Police alleged he shouted "get this into you" during the assault.

The accused then allegedly got out of the car and threw the hammer at the windscreen and shattered it.

The car belonged to the third man drinking with Mr Jones and his son. He fled after the alleged assault but had since given evidence to police.

When police found Mr Jones nearby he had blood on his clothes. He was arrested and allegedly told police his son "deserved what he got".

The victim was in Nepean Hospital being treated for a compressed fracture to the skull.

At his bail hearing in Parramatta Bail Court on Saturday, Mr Jones, of Penrith, was said to have "no apparent contrition". The court was told he had a long history of dishonesty and break and enter offences.

Mr Jones was granted bail under strict conditions, including an order not to approach or contact his son or the third man drinking with them.

He will appear at Penrith Local Court on October 31.