Bj74 broke down in MT, Water Pump and Thermostat

[Rustybones]

I'm currently on a road trip through the western united states. A couple of nights ago my thermostat froze in the closed position and we over heated. We've been limping towards the border and are now in Helena MT, visiting some friends. Our situation currently is that the thermostat is out and we're using card board to regulate the airflow for the rad. I've tried to cross reference the thermostat part number at a few napa locations throughout oregon and idaho with no luck. The main problem is that the water pump is acting up. Yesterday we drove 500+ mi with no problems after tightening the fan belt because we noticed it was loose the day of the thermostat closing. We overheated one more time on Macdonald pass last night, not a bad one, caught it early, but it made us realize that the water pump goes through surging cycles where it won't pump, we notice this by sensing fast changes in heater blower temperatures. The temp gauge on the dash will show medium and the blower will be blowing cold air, which to me indicates the water pump is not cycling water sometimes.

I'm looking for advice on how we can keep driving this truck without the water pump fully seizing and if a 2f or 3b water pump is interchangeable with the 13bt, or if there is another thermostat out there?

Sorry about the long post, ask for any clarifications.

cheers

 

[Captain Caveman]

Napa thermostat: ATM 1542401
Napa Waterpump: ATM 1529210

OEM waterpump: 16100-59105
OEM gasket: 16271-60012

If your heater is blowing cold air it is usually because you are low on coolant.

 

[Rustybones]

Captain Caveman thanks so much. That puts me at ease. I'm hoping that American napa locations have that thermostat. The heater temp problem makes sense, now we just need to figure out how the coolant is dropping. I haven't seen any leaks yet. Time to go visit the helena napa

 

[Phil in BC]

Hopefully you didnt blow your head gasket as well. That may be where your coolant is going. When I blew mine up it was puking coolant out of the overflow tank. I also had symptoms like you are having now. Good luck.

 

[Captain Caveman]

Hopefully you didnt blow your head gasket as well. That may be where your coolant is going. When I blew mine up it was puking coolant out of the overflow tank. I also had symptoms like you are having now. Good luck.

That is what I was thinking... I also had the overflow tank puking, but coolant could be leaking into the cylinders and getting "vaporized" with the compression. Does the exhaust smell different than normal?

 

[lshobie]

Is your rad plugged? Sounds like your heater core might be plugged as well. I'd look into that. For a water pump to intermitantly not pump doesnt sound right and is almost impossible. Also - hows your fan clutch working? Why would you use cardboard for covering the rad if it is overheating - keep the cardboard off at all times. you can run the truck with no thermostat as well. Or are you doing this so you keep heat?

Rad flush or new 4 core rad is my suggestion - as well as new fan clutch - not rebuild but new.

Louis

 

[Rustybones]

we were covering the rad to keep heat, southeast oregon and MT were freezing. I'll keep an eye out on coolant levels. I'm putting the new thermostat in right now. Hopefully the HG isn't gone.

 

[lowenbrau]

My money is on low coolant and air in the system. 70s are a paint to burp. Turn the front and read heater controls to full hot. Pull off a heater hose ( the highest one) and fill it from there with the engine running. Shut it down and close it all up and squeeze the top rad hose a dozen times. Check to see it it will take any more coolant. Repeat as necessary. Warm the rig up and then let it cool (be sure the overflow tank is full) about 6 times.