Radiator overflow bottle keeps filling up

[bhaugen]

yup my overflow bottle fills up when I use my bobcat. it is a 773G. I replaced the radiator cap, and it still does it. One question I have is what is the original pressure on the radiator cap. I put on a Napa 13 lbs cap same as the one that was on it. Or do I have a head gasket issue?

 

[OldMachinist]

Does it stay outside in the rain. Mine did that too and I thougt I had a head gasket problem too until I put a tube fitting in the hole in the overflow bottle cap with a tube running down the side of the bottle. I hope that makes sense. Since then the level in the bottle hasn't changed. Some how rain water was getting in that little hole and over filling it.
Original 773G Bobcat radiator cap was 14 psi.

 

[bhaugen]

Does it stay outside in the rain. Mine did that too and I thougt I had a head gasket problem too until I put a tube fitting in the hole in the overflow bottle cap with a tube running down the side of the bottle. I hope that makes sense. Since then the level in the bottle hasn't changed. Some how rain water was getting in that little hole and over filling it.
Original 773G Bobcat radiator cap was 14 psi.

No it fills up while using it. It will not recover the antifreeze back into the radiator. I will go by the bobcat dealer tomorrow and get an oem cap. 1lb can make a difference.

 

[Tazza]

No it fills up while using it. It will not recover the antifreeze back into the radiator. I will go by the bobcat dealer tomorrow and get an oem cap. 1lb can make a difference.

Sadly, it sounds like a crack. Are you getting any bubbles in the over flow bottle?

 

[Fishfiles]

Sadly, it sounds like a crack. Are you getting any bubbles in the over flow bottle?

did you take a look under the oil cooler to see it the radiator is externally plugged up with dirt and if you air blower fan belt is on , tight and the idler/adjuster has a good spring motion to it -------- what you need is a radiator pressure tester to put on the radiator then run the engine , if it is building pressure you will see it , another tool I use is a exhaust gas detector , pretty cheap at under $100 , you mount it on the radiator and put yellow fluid in it , run the engine and if exhaust fumes are present it will turn blue , you can get one at Napa

 

[bronkobillie]

did you take a look under the oil cooler to see it the radiator is externally plugged up with dirt and if you air blower fan belt is on , tight and the idler/adjuster has a good spring motion to it -------- what you need is a radiator pressure tester to put on the radiator then run the engine , if it is building pressure you will see it , another tool I use is a exhaust gas detector , pretty cheap at under $100 , you mount it on the radiator and put yellow fluid in it , run the engine and if exhaust fumes are present it will turn blue , you can get one at Napa

had a similar problem the overflow bottle got plugged with dirt on the bottom and could not suck it back into engine.it wasn't to long and machine would boil fluid into the overflow but there was no way to get it to cycle back into the engine.cleaned overflow tank and problem disappears.Lots of dirt around in there to find its way into the tiny hole in the overflow bottle cover