ok, new radiator put on in march, new hoses 1 week later, new rad. cap on tuesday (i was still losing a small amount of fluid and thought slow seeping from bad seal on cap)...tonight i shut the car off and hear large amounts of fluid rushing from under my hood, look on the pavement to find coolant puddling up under my 2000 disco II. AAAHHHHH!!!! Pop the hood and see coolant spurting out from the overflow tube. Is my radiator cap maybe too tight??? Wrong size??? What causes the fluid to expand so much that it tops out of the resivoir???? I am tired of weekly trips to the mech about this ongoing coolant saga.

 

The most obvious answer is that your system is overfilled and the overflow tube is doing it's job.

That said, it's possible that you have anobstruction in the system that's causing the fluid to back-up, for example. If the coolant level in the overflow tank appears to be normal/correct when the truck is cold, I'd start by bleeding the system. It's possible that this wasn't properly done after your recent repairs and there's air in your system (causing poor/restricted flow and/or too much pressure). If there is too much pressure/volume via air and/or an overfill, it's possible that your old, leaking cap was allowing vapor pressure to escape.

The new cap may be responsible for bringning something else to a head, but it's not to blame. The cap should have a tight seal.

Are you having any overheating?

 

I would suggest you quit driving the truck before you drop a sleeve and loose your engine.
Call me and I will walk you thru a few things to check.
Mike
303-862-7680
Colorado

 

never had any problems with overheating. i was topping off levels once a week a found a pinhole sized leak on the radiator. replaced it and 2 days later the bleed screw sheared off the hose and had to replace those. (btw- new T joint for bleeder hose seems A LOT smarter!) still having to top off levels (a few ounces every week) so tried a new cap to see if i was loosing fluid because of old cap. put new cap on and topped off on tuesday. everything seemed fine until last night. drove a short 5 miles and parked at home. that is when the spurting from the overflow happened. dashboard guages still seem to be steady in the middle.