In the tow truck as we speak....2000 D2, new rad (today), new t-stat (last week), most hoses new, water pump <1yr ago.

Replaced the rad and for an hour it ran fine, best heat the truck has ever had.

After

After an hour, I noticed that the coolant reservoir cap was hissing and leaking fluid. It has been removed/replaced quite a bit recently. Lost heat, truck overheated.

My guess is that the cap failed which introduced air into the system, causing it to overheat. I did bleed the system properly after installing the rad.

Do you guys agree or do you think that it's something else.

My plan is to replace the tank, the cap, and the throttle cooler hoses. What else should I consider?

PS: thanks in advance.

 

sounds like your just throwing parts at it $$$, what was your original problem?

have your preasure test it for a leak yet? or checked your coolant for Co2

 

Hold off on the parts throwing contest just yet. If you lost heat, you were low on coolant, and may have quite a leak somewhere. If not head gaskets or cracked block/head (chemical test) then you could have a leak under pressure when driving that does not show up when parked. Borrow a cooling system pressure tester, pump up to 15 psi and wait 15 minutes for leak to show itself.

A chemical test, some stores sell it, some loan it out, will check for exhaust gas in coolant, it changes color. Usually that much coolant being burned off makes white smoke out the rear or milkshake out of oil (internal leak).

 

Thanks for your response. My original problem was that my engine was overheating. With the help of some kind forum members, we were able to reasonably troubleshoot the issue back to the radiator.

My mechanic wasn't convinced initially, so I let him talk me into a t-stat. I let him swap it out and the thing overheated within 15 mins. He also "blew out" the heater core.

I haven't pressure tested it or checked for O2 in the coolant. I figured that since it ran fine until the cap/reservoir/both seemed to fail, that I would replace them.

 

Thanks, Buzz. Exactly - the leak in this case, appears to be a failed cap/reservoir, or both. I confirmed visually that antifreeze was spitting out of the cap.

 

Time for a coolant pressure test, need to be able to hold 18 pounds for at least 15 minutes, also test the cap then get back to us.

 

Pressure tested 18 psi for about 8 minutes' then the universal (wedge-shaped) tester blew righ out of the reservoir. Backed it down to 16 psi, pressure held for 15 minutes. Good news, right?

The cap, however, couldn't get up to pressure. Air hissed right past the seal.

 

Yes great news go get a new cap and make sure at all cost that it dies not over heat again your very lucky you have not caused damage yet....good to see you back Mike!!!

 

Thanks everyone, and yes, nice to see you back, Mike!