GUNNER

I run a yanmar i.5 ton mini digger for my work and wondered if there are any plant fitters on here that can tell me if the hot water from the engine exits from the the top hose into the rad and then filters down through the rad where it cools via the fan and then enters the engine again via the bottom hose, or wether the system works in reverse to the above i.e. the hot water exits the engine from the bottom hose etc. any advise would help please.

mike.

what would scooby do

why don't you feel each hose when it is running, that will show the circulation..

BOB.T

Hot water should, usually, exit via the top hose as you say. If it's not, you've either got a blockage, most likely a knacked thermostat or your water pump isn't working.

GUNNER

Thanks Bob, the top hose is twice as hot as the bottom one which makes sense if the water has just been cooled, the reason for asking the question is because i had a freeze up in the cold weather and lost all the water due to the bottom hose coming off the rad, it split the heater matrix also. i looped the matrix so i could use the machine but under load the water forced it self out the top of the rad cap. i noticed the rim to which the cap seats on was forced up on one side, so i tapped it back into shape with a copper hammer and fitted a new rad cap. the machine has been run today with fresh antifreeze mix, a repaired matrix and a new rad cap. All seems well while sitting still with engine running flat out, and the matrix is giving good cabin heat but this is when i noticed the different tempertures in the hose's, thinking there may be a stat prob also i needed to know which way the water is pumped to try and work out wether the top hose was so hot because it could'nt enter the engine or it was because it had just come from the engine on its way through the rad for cooling.

BOB.T

Sounds fine to me, assuming the temp gauge is steady? If the top hose is hot it means the stat is open.

GUNNER

No temp gauge, just a red warning light. i've never seen this come on so will check it today for faults, bulb blown broken wire etc. might even fit a gauge in its place. The machine is going to work tomorrow so fingers crossed, might even try it best i can at home.