No work on the XS650 project last week. I drove my trusty 459K miles El Camino to the bank drive up teller and noticed when I left the transmission slipped for the first time ever. I pulled into the parking lot and when I opened the hood I noticed the radiator overflow tank puking out a muddy brown sludge. This can`t be good. AAA to the rescue as always. The trans cooler part of the radiator has ruptured letting antifreeze into the trans and trans fluid into the engine cooling system and so on. I drained the engine and trans and bought a new radiator and filled the system with water and cleaned the overflow tank and left it unhooked from the radiator and ran a hose from the radiator overflow down to the ground in case it overflowed. No drain plug on the trans pan or converter so its put the truck on jack stands and remove the trans pan each time I changed the fluid. (7) times in all. After the 4th radiator change the water was almost clear and I added some radiator-block flush. The trans started to clear up on about the 5th fluid change. Each time I changed fluid I let the engine warm up to operating temp and drove it around the neighborhood close to my shop. The trans shifted just fine each time even with contaminated fluid. On the 7th change I added new antifreeze and a new trans filter and gasket. I`ve driven it about 150 miles this weekend and no issues. Transmission fluid is still a transparent red like it should be. I`ll change it again at 500 miles. Looks like I dodged the bullet so far. This little venture cost me $260.15 so far. It could have been much worse. I`m going to milk a half million miles out of this truck if it kills me and putting it up on jack stands 7 times and crawling under it for each fluid change almost did.