I'm in the process of restoring a 1998 F3. I drained all the fluids the other day and today I took off the radiator and noticed that there was a lot of brown deposit in the lines, I flushed distiled water through the top of the system but that didn't seem to get everything out. So I took a garden hose and disconnected the water hose from the oil cooler and sprayed into the bottom radiator hose, which sprayed water out of the water hose for the oil cooler and cleaned it out pretty well. Then I hooked the water hose back up to the oil cooler and decided to spray again. This time I got water coming out of the drain plug for the oil . I thought these systems were both closed from each-other and I am wondering what this means. What do you guys recommend?

 

I had the same problem on my first cbr after it threw a rod on the highway, the shock in oil pressure blew out a o-ring. The o-rings in the oil cooler help seal the water jacket from the oil cooler its self. If there is slight defect in the o ring, it will leak under pressure, from the sounds of it, there not even be o rings there.




Also, make sure you put the oil cooler and filter back on before you fill the system with water again.

Hope you understand my ways of explaining.

 

There were o rings there but I am going to replace them, they do look a little worn. Hopefully that solves the issue, I will update with progress.

 

Replaced the all o rings on oil cooler. No change . Thinking it might be a head gasket, but I would be surprised if I could generate enough pressure with a garden hose that far down the system to see water there.

 

You sure you arnt putting the water through the oil filter holes?

 

Very sure. I decided to reassemble everything and fill the radiator to see what happened. There was a leak near the top of the engine. I'm going to have to pull the tank and air box off to see exactly where its coming from.