B7100HST - Flushing the Cooling System

[Full-Pull]

I recently acquired a B7100HST, but don't have a WSM yet.
I'm doing some "baseline maintenance", so I know where things stand, as well as getting to know my new orange chore pal.

Made the first visit to the local dealer today (helpful, friendly guys), and picked up new coolant hoses. What is the preferrred method of flushing the cooling system? Any particular details in servicing a thermosiphon system?

And a second, unrelated question: I'm gonna change the hydraulic fluid & filter this weekend; what is the torque spec for the screen/filter bolt on the suction hose bolt union?

Thanks for the help folks...this place is a great resource.

[Service Dept Vic]

Full-Pull,

Welcome to the site!

Sounds like you already have a good understanding of mechanics, so flushing and re-filling the rad will be just as you think.

Open the drain, drop the old coolant, refill with new 50/50 glycol and water.

Clean the low water whistle if your B7100 has it, make sure the rad cap is in good shape, remove the front grill cover and clean the fins on the rad and the transmission cooler.

As far as the torque spec goes on the suction filters, (your Kubota will have 2 of them. One for the 3 point hydraulics and one for the HST motor) they are "straight cut" on the treads and will naturally "bottom" on their own as you tighten them back up.

Don't loose the small brass sealing washers when you are withdrawing the suction screens and remember to change the HST canister filter as well.

[Michael]

To flush a badly corroded cooling system, I first remove the themostat and chuck it, I then just put the themostat housing back on without a gasket and reattach the upper hose temporary, I also disconnect the lower hose from the radiator and place it in a five or ten gallon drip pan. I then get my garden hose and a bunch of rags and wrap the rags around the garden hose until I have a snug fit on the upper radiator hose and turn the water on and let the water flow through the cooling system until no rust appears in the lower end. I then reverse the garden hose (I connect the garden hose to the lower hose and run the water from the bottom and let the water flow go the opposite way until it runs clean out the upper hose)

I then disconnect the hoses from the engine and connect the hoses to the radiator side and do the same on the radiator side. I then reverse the garden hose in the same matter as doing it on the engine. I have never used the harsh chemicals as I have always felt that they cause more damage then what they are worth.

After draining the water out of the engine after this method I then replace the themostat with a new gasket and replace both the upper and lower hoses with new hoses and if a bypass hose is used I also replace this.

On a cooling system with minor rusting and scaling I simply do what Vic is suggesting and just drain and the system and fill with water, (leaving the radiator cap off) run it for 15-20 minutes and then drain again then refill with the proper mixture of 50-50 water antifreeze.

Note on themo syphon systems I just skip the part of trying to replacing a themostat that does not exist....

The reason I replace the hoses and themostat is the reason is how long have they been on the equipment. If I can not answer the question then it is replaced as I am not going to be out in the field and have a hose burst or a themostat get stuck. I have always had the attitude of once in for service then I AM GOING TO REPLACE any wear parts so I know when the parts were replaced.

[takattack]

50-50 water and antifreeze? why not paraflu?

[Full-Pull]

Thanks again guys. About exactly as I envisioned.
Yeah, I'm pretty gearhead-savvy (I think:confused:), and well-equipped for the most part.
There's always something to forget...I noticed a small chunk out of the coolant pressure cap lip, but I didn't have it on my 'dealer list'.
And looks like they only gave me one set of o-rings for the strainers.
Oh well, I gotta go back anyways: they backordered an oil seal for the weepy front steering knuckle.
Takattak,
No Idea what "Paraflu" is...just gonna use the garden-variety automotive stuff I have in the shop; temp range here is not extreme -- +15F - +85F.

Ted

[gktilton]

Paraflu is an antifreeze made by FIAT for FIAT's. I just use Prestone.

[asbug]

I just did this on my B7001 this weekend.
It appears that I didn't have a thermostat, so your mileage may vary.
I cut one of the old hoses (top) and found that a 3/4" PVC pite to threaded adaptor is a tight fit in the hose. My garden hose will then screw in tight enough to seal in the PVC.
I then crank up the hose which is now sealed in the top hose neck, and you will blow all the sludge/rust out of the bottom (disconnected at radiator) hose.
There was a non insignificant amount of rust that came out of the block.
After flowing it clear for a few moments, I then reversed the flow throught the bottom to the top (Some scale flakes) and then again top to bottom ( a little more rust).
I am satisfied that this cleaned it as well as it possibly could...
KC