no pressure in cooling system

Can anyone offer any ideas as to why I have little pressure in my cooling system? We had the water pump replaced a year ago in December and have had problems since then. At first it wasn't leaking enough to detect and now it is leaking from somewhere but can't really tell from where and it is getting worse. We ordered a new fan clutch and will be putting that on soon. We also just put a new thermostat cap on and it still does not seem to be holding any pressure. My heater is not producing heat like when I bought the truck and it is starting to frustrate my husband and give him nightmares! Please if anyone has any ideas please let us know, thank you!

Bren and Al

Probably water pump you put in before not bad but not right take it back and get a new one that is the only thing it could really be

Find a radiator shop or repair shop that can run a cooling system pressure check. They use a pump to pressurize the cooling system and that will help locate the leak. Your fan clutch has nothing to do with cooling system pressure. There several areas other than the water pump that could be causing the leak, hoses, radiator, heater, intake manifold gasket, and head gasket to name a few.

Clifton

Your water pump is the only motive source to create necessary pressure.

1. Check your serpentine belt is it slipping? Check for glazing on the belt/pulleys.
2. Is your idle-pulley tensioner failing? It should offer considerable resistance along its full range of motion. Slop in the tensioner would also affect alternator/power-steering/AC-compressor as well - check them out.
3. You may have air in your cooling system causing the water pump to cavitate on an air-pocket. Have your system properly evacuated at a reputable shop or get then learn how to use the tools to do it yourself.

the water pump does not create pressure,it circulates the coolant.the pressure is created by the heat that is produced when the engine burns fuel.if your belt was slipping or for some reason the pump was not working you would probably have a lot of pressure in the system because it would be running hotter than normal.so like Flash said,you need to get it pressure tested to find out where it is leaking.

It sounds like you need to drain your entire cooling system, then pressure check each component. You state you have a leak in the system. Did you check your engine oil to see if it's milky? If it is you may have a head-gasket and/or intake manifold leak (presuming wet system).

How much coolant are you losing/day?