I've gotten so much help with my truck just by reading and searching this forum, but I'm stuck on this issue and hope someone would be willing to help out.

My truck overheats, especially when under load.

1949 F6 239

The truck sat for 25-30 years. Someone started it up about 5 years ago (new coolant, oil, plugs, wires, etc) It sat again for until I got it.

I put new temp sender in the drivers side head and then I got new tires on it and drive it back 15 miles from the tire shop. It started reading hot. I stopped and let it cool and restarted. It started dumping lots of coolant and I was having to add water every 3-4 miles.

I got a new radiator cap (4 psi). It slowed coolant leak, but it still overheats.

I thought stuck thermostat... got new t-stats and pulled housings. No t-stats installed.

I've:

* checked water flow on each head by removing upper hose, running engine and verifying water flow. Water only flows under acceleration but then its voluminous.

* checked exhaust for restrictions

* drained all old coolant (looked clean), flushed radiator and block with water hose (looked like good flow), currently it has Blue Devil flush in the system.

* gotten Block Tester and tested four times. Blue never changes color

* Replaced all hoses

I'm stuck. I don't know whether to try pumps or buy a repop radiator.

Does anyone have any clue?

--- couple other details to add ---

Doesn't seem to ever get more than 3/4 hot on gauge at idle.

Gauge drops to just under half if I accelerate with no load

It takes about 10 minutes of driving to go from cold to almost all the way hot on the guage

Passenger side head seems to stay cooler longer than drivers side (just by touch when heating up)

----

Many thanks in advance.

Bram

 

Do you have an infrared laser temp gun? I would suspect the gauge or sender first. If you don't have a gun, warm it up with the radiator cap off, and stick a meat thermometer in the tank.

Are you filling it to the top of the tank? The Full level is at least an inch below the filler neck (some radiators have a brass strip at the proper level. As long as the tubes are completely covered, you're OK.

Aside from cooling system ailments, retarded timing or lack of spark advance will cause overheating.

 

My 53 c600 with flathead would overheat within a few miles of driving.
I pulled the radiator and had it professionally cleaned $65 later and also new thermastats it runs fine and guage never goes up past a "H" which I assume is 180 since that what t stats i put in.

 

I bought a temp gun today and a timing light. Will check timing and temps and report back!

 

How did the cooland look when you drained it to pull it? What do you mean by past a H?

Thanks,

Bram