Low Coolant Pressure

workin' diesel

factory tuned
Nov 13, 2010
630
0
0
Coalhust, AB Canada
I have installed on the truck a coolant filter system. On the filter head there are four ports to hook hoses up. in one of those ports I put a water pressure gage I got from Menards. It only reads 7psi by the time I get to work. Wondering it there is a pressure loss somewhere(no fluid leaks that I can find), or if the cap or thermostats are bad. Basically I was wondering what would give it low pressure. Or maybe that is not such a bad problem
 

chevyburnout1

Fixing it till it breaks
Aug 25, 2008
2,368
1
38
Berthoud, CO
Depending on how you drive and the temperature that sounds normal. I can daily drive my truck through town for 30 minutes and still be able to take the coolant cap off. I think you will only see the higher pressures under high temps and loads.
 

workin' diesel

factory tuned
Nov 13, 2010
630
0
0
Coalhust, AB Canada
Just curious. There are no issues with overheating or anything of that sort. It just seems that is takes a lot of effort to get the cab warm. I was not sure if low pressure meant low circulation by the water pump. As far as I can tell the pressure cap and the thermostats have never been changed.
 

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,339
373
83
Central OH
Where are your lines hooked in to? Pressure sounds fine, it will go up with rpms as the water pump flows more water. Coolant pressure at idle is more dependant on temps. To see a real problem you need two gauges to see differential pressure between in/out.
 

workin' diesel

factory tuned
Nov 13, 2010
630
0
0
Coalhust, AB Canada
The input line comes from the out going heater core hose and the out put line 'T's into the overflow tank line. The gage also shows temp, but it is usually only 100-120 degrees sometime not even that high, but that is because some of the heat has been taken off for the heater.