According to it's specifications the Brother HL5370DW supports PCL6.
Please try the different PCL6/5e drivers offered under the manufacturer "Generic". Especially try the PCL-6/XL printer with "Foomatic/pxlmono" and the PCL-5e printer with "Foomatic/hpijs-pcl5e".
Does it work now?
According to it's specifications the Brother HL5370DW supports PCL6. hpijs-pcl5e" .
Please try the different PCL6/5e drivers offered under the manufacturer "Generic". Especially try the PCL-6/XL printer with "Foomatic/pxlmono" and the PCL-5e printer with "Foomatic/
Does it work now?