1995 4.2 cracked coolant expansion tank, need advise

[jdsmith46]

Ok. I bought a 95 lwb from a guy who had just cracked the coolant expansion tank. (i was present when it happened) The truck never got into the red but was close. He had the top end redone last year with new water pump and thermostat.
I took a chance that it was hopfully a bad tank since it cracked near the neck. I ran the truck today and at idle it never overheated. I put a new tank in and it did not overpressurize,yet. I did the test for the exhaust gas in the coolant and it was negative, it was nice bright blue fluid.
Now I did find that i could stop the fan with my water bottle during start up and after 30min of running.
The question is could this bad fan clutch be a true culprit of cracking the tank?? Please give your insight to this.

 

[Discoinjapan]

The question is could this bad fan clutch be a true culprit of cracking the tank?? Please give your insight to this.



Cracking the tank, probably not but it should be changed cheap fix. You replaced the tank, did you replace with a new cap too?

 

[jdsmith46]

ordering the cap this weekend. I am not going to drive it until I have all the parts in place. I am sure it is well due for a new cap.

 

[Discoinjapan]

I would order a new fan clutch also.

 

[jdsmith46]

I guess at 148,000 miles it could crack given its age

 

[Discoinjapan]

Most likely the cap is what was bad. They fail and the system will over pressurize causing the tank to give out.

 

[p m]

Was it a black or tan tank?

Many 95-96 years' black tanks have been of poor quality.

 

[Ron]

Black tanks explode for no apparent reason. I am waiting for mine to blow (nearly 170k on the original black one knock on wood). If it is not running hot, a new tank at ~$50 is all that is required (unless something else is obviously at fault).