Coolant Pushing Out Of Overflow

[Erben]

I have coolant pushing out of overflow on my semi-tractor. The mechanic can't find the problem. Have you ever dealt with this?

 

[Kozzy49]

I have coolant pushing out of overflow on my semi-tractor. The mechanic can't find the problem. Have you ever dealt with this?

Many years ago I was a Heavy Duty Mechanic. Before panicking, take a look at your rad cap, is it in good shape, If the gasket is in good shape and the cap tests for proper pressure. If cap fais test, buy new cap and see if the problem persists. If problem still around, take off rad cap and let the engine warm up. Do you get a lot of bubbling? if so, have someone watch the bubbling whie you crack a fuel line of an injector, after 5 - 10 seconds does the bubbling decrease or stop? If not close that injection ine and crack the next one, repeat above observation untill bubbling reduces or stops. If you have electronic injectors, some scan tools can isolate injectors without having to disturb the injection line. What we are trying to see is if we can find were the bubbles are coming from. If this did not cause reduction of bubbles, remove thermostat and put in water, heat water observe temperature thermostat opens. If water is over temperature declared on thermostat, replace thermostat. Before installing new thermostat, close up coolant system without thermostat, fire up engine and watch for bubbling, if bubbling persists, I would suspect a cracked head. However this will also often cause coolant build up in oil, white exhaust (coolant getting into intake or exhaust). Look for external signs of leakage near intak and exhaust manifolds, mmay give indication of where leak is. Final chech get a radiator test kit, pump up the radiator to radcap pressure, see if pressure leaks down. Take a mechanics stethiscope or a screwdriver and listen for sounds of air escaping. Listen along intake and exhaust manifolds, where sound is loudest is where your leak is. Hope this healps.