How to redo thermostat (and install trans cooler) without losing much fluid

[DK327]

A couple of months ago, soon after I got my truck, I had the stock radiator, cap & hoses replaced, got a coolant flush and had the thermostat and gasket replaced.

After getting a ScangaugeII I discovered engine temps were 202-207 which is on the warm side. I did some research and came to the conclusion (later confirmed by mechanic who did the job) that thermostat jiggle valve was positioned at 12pm instead of 6pm.

My question is, since I just had a coolant flush, how would I go about redoing the thermostat (and also install a trans cooler while I'm in there) without losing much coolant? I do have another gallon jug of Toyota 50/50 coolant so if I have to do another complete flush, would 1 gallon be enough?

Edit: I suppose I could drain the coolant into the old jug that I kept and then refill the radiator when I'm done without losing anything... Duh!

 

[pauldub]

One gallon isn't enough for a complete flush. Since the coolant is relative new anyway, just strain it and reuse it. You're just straining out that grit that gets in it while it's draining out.

 

[4racer]

I agree. Reuse the coolant. Thermostat is a quick job. Because the coolant comes out of the valve on the bottom, its relatively easy to catch it. I would get a new Thermostat gasket, but thats just me. Had a couple instances on other cars where they leaked.

 

[nobb]

I've drained the coolant into a clean bucket then filtered (via coffee filter) that into a clean enclosed jug before pouring back into the radiator.

Your initial bucket will have to be wide to catch everything, but you'll always get some dirt. Unless you are really careful, you will also have some minor coolant loss so make sure you have some top off.

 

[Drcoffee]

So heres my two cents. I just did my timing belt and water pump and had the t-stat in the 6 o'clock position. Found out I was running at 208*. WTH! So I took the failsafe t-stat back to autozone for a different brand. Installed it and WTF! It also was running at 208*. So I broke down, drove 30 minutes to Toyota for an oem t-stat. Whamo! 188* all day long. The moral of the story is OEM is the only way to go.

How to do it? Place a 5 gallon bucket under the radiator drain and let it drain. Swap out the t-stat and before I refill the radiator, I use one of those gold coffee filters that came with our Braun coffee machine and put it in the funnel. Then pour the coolant back into the radiator using the funnel/filter combo. We never use the gold filters for our coffee. The paper filters filter out the bad oils in the coffee during the brew.

 

[Kotrin]

So I did my trans radiator 2 weekends ago and lost like 1/2 a cup of fluid. I didn't drive it for 2 days before hand and as soon as I removed the hoses i put them up and kinda capped them on both sides. I check it and run my SGII and still show full and GREATtemps so far. My trip in a few weeks will be the 'true' test.

My best suggestion is get some items to plug the lines your pulling, golf tees or small items to insert or cap it off.. my 2 cents..