CM870 oil pressure low. jakes not working

[jjoshthomas074]

Sorry i started rambling on a little. I'm definitely going to change the oil before putting truck in service it was the first time switching to this oil... i definitely regret it!! just to reiterate. idle at operating temp 20-23--- 1500 rpm at operating temp 30-33... i thought i read Cummins minimum spec was 15 at idle 35 at "operating speed" whatever that means? Thought it was on the low side of spec maybe I'm wrong. i will have to confirm the oil temp again i thought it was up over 200 in a fairly short time ''1hr'' of stop and go. just wanted to note the jakes were not coming on, thought maybe it would have something to do with oil pressure on the lower side of spec. not asking how to go about making any repairs on them at this time. Thank You