Hey I have a 175c loader with a old international 466 maybe a B model, I have been having issues with the the radiator building up pressure an spitting out of the radiator pop off safety valve, look over in the rad. an its full off tiny foam like bubbles, at an idle the water is somewhat stable , but if you idle it up to qtr throttle or more itll start bubbleing small bubbles an looks more like foam, so I though my head was cracked, pulled it off an found that there had been water damage to 2 pistons from leaky fuel cups, took head to machine shop an they checked for cracks , said it wasn't but the injector tubes were shot so they were replaced plus did a valve job. mean time while waiting on head at machine shop I did a inframe on the bottom end, everything went well, after the inframe I can run the loader for nearly 30 mins to a hr some times till it starts blowing water outta the top of rad. safety pop off relief valve, so needless to say I haven't fixed my compression in the water issues yet, I took a 5 gall bucket an ran a hose from the rad. pop off relief valve down into bucket an ran the motor an after lil while of running it started pushing water into bucket, I had put some BARS LEAK HEAD GASKET AN CRACK SEALOR in system to hopefully find leak, so I let it keep runnin an watching it after nearly20 mins I had maybe 2 inchs of water in bucket an then I could the air bubbles comeing outta the hose in bucket, I kept watching it 30 more mins. then I saw my bucket was steaming up really bad an acted as if was over heating an blowing water in bucket an stilling outta hose, I then shut motor off an looked into bucket an it was nearly half full of water, an after it cooled down it drawed the water back into the rad.,, it sounds as if I had a cracked head or bad gasket or bad injector tubes, took head back off an took it back to machine shop an they looked it over an said that its not warped ,cracked,nor leaking injector tubes, an head gasket looks great too. I have looked at the piston liners an ran a leanior projection on them (measureing the liner heath from block base) an seems to be within specs. I took the thermostate outta the motor to make sure its not it, still builds press. I have not changed the water pump tho but that's because itll build pressure up in rad. before the water temp. ever climbs up any. ive looked everywere for help here on my issues , anyone have any ideas of were my bubbles are from,, like I say good head, good gasket, good injector tubes,new liners an at rite height
This sticks out to me, I wouldn't think the engine would suck the water back in if it was leaking compression, but maybe? Also the bucket getting hot makes me suspect it was some steam coming out of the hose with air. When it warms up there is some air that comes out of the water. Were you using straight water or antifreeze? Filled to the top of the radiator or a couple inches down? Test the thermostat and put it back in, it's there for two reasons. Pressure test the cap? Did you check the radiator temperature top and bottom when it had run and spit out water? Of course it could be a crack that opens only when it's hot, but that's not what you want to hear.