Archived Overheating...need help

[kad]

I'm bouncing this over from the 1st Gen forum. I recently developed a leak at the water pump seal: The symptoms were coolant spray sourced to the junction of the lower lip of the water pump to block mating surface-not the weep hole. The temp gauge was fluctuating at that time but not overheating and I had cab heat. I replaced the water pump and seal (new from Cummins) which stopped the leak. Now - no leaks- but the truck overheats within 10 min of driving, there's no cab heat, the rad hoses remain cold when the temp gauge is pegged, seems like no flow thru the motor. I replaced the thermostat with no change. Obviously I'm having a craniorectal inversion on this problem...

I need to get 200 mi into west texas to do some welding ASAP and I'd rather not have to rent something and transfer all my crap over... any ideas out there?

Many many thanks,



kad

 

[mberry]

Sounds like a vapor lock on the new water pump. Take it to a Cummins or a radiator shop and have them do the vacuum on the system to get all of the air out. At least I think it's a vacuum pump. Hope this helps.

 

[kad]

Air... Should of thought of that,

thanks,



kad

 

[TBartlett1]

First make sure the radiator is full to the neck then you need to get a radiator pressure tester (Stant) and pressurize the system if it takes more than 3~4 pumps to pressurize to 10~15 lbs you have air in the system. Next start the engine and let it run, you can jazz the throttle to help move the air. The Cummins thermostat has what are called jiggle pins in them (some had only 1) and must be installed with the pin on top to allow air to escape, this takes some time and will may help if the truck is pointed uphill. With the system pressurized it will compress the air and allow it to be moved thru the system and into the radiator. While it is running under pressure feel the heater lines, they should start to get warm if not slowly release the pressure and check the coolant level and top up if necessary then pump the system back up this will work the air out. Do not run the truck on the road until you get heat, my brother in law did it and cracked a head. This could take several minutes.



Hope this helps.

 

[Joe Mc]

Bingo! Do "exactly" as TBartlett1 recommended, worked for me - I'm lucky cause the driveway slants and I drove nose up. If you have a flat drive put it on ramps or stands. Every little bit helps.