Builds Project Pikachu: 1977 FJ40 (3 Viewers)

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@Bad Mojo how does a citric acid flush work?
Was the coolant you drained clean? If so and it’s draining fine you don’t need to do that.

If you had Rusty looking coolant then you should do a flush
 
I was trying to Google it. Never heard of the process
From my understanding it is part of Mercedes scheduled service for cast iron blocks. I had to do more reading on Mercedes forums, but I stumbled across it the 80 series section initially.
@Bad Mojo how does a citric acid flush work?
It works as a mild cleaner to help clean up corrosion build up. My understanding is that while coolant has anticorrosion agents in it this helps do a little clean up of what couldn't be prevented. I wouldn't do this as yearly maintenance, but would consider it each time I was changing out coolant or baselining a truck with limited service records.

Step 1: Drain old coolant out.
Step 2: I believe we pulled the thermostat to have full flow
Step 3: Filled the cooling system with distilled watered and citric acid powder.
Step 4: Run truck to temperature.
Step 5: Drain out.
Step 6: Repeat 1-4
Step 7: Fill with just distilled water
Step 8: Run to truck to temp
Step 9: Drain and repeat until satisfied with what is coming out.
Step 10: Any other coolant system maintenance and install thermostat
Step 11: Fill with final coolant and enjoy.

The one thing I did read and why I was okay with doing it was it can break up any sediment or stop leak that is keeping a leak from occurring. That truck was going down for a full cooling system overhaul and I waited until after the flush to replace the water pump. I would do the flush again for anything getting a water pump or other major cooling system work.

Below is a picture of some of the water that came out during the flushing. Also the coolant that was initially in the engine was red to begin with and I wouldn't say dirty or rusty, but was of unknown age and quality. During the filling and burping of the cooling system a brown foamy sludge would float up to the top of radiator where water was being added.
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Thank you for the detailed post, @Bad Mojo.

Since I have pretty much all new-ish components in this cooling system now, I am going to start with putting in new coolant, especially since the block drain was clear when opened up and I think the passages are in decent shape.

@wngrog the coolant was still clean and green.

This is a gamble on my part with an assumption that the radiator was the problem. Will post more later this week when I have time to fill/burp/drive the 40.
 
The new radiator seems to have solved my issue. Finally was able to put a few miles on the ole rig today and Pikachu ran just great.

Also went and checked on a friend’s property to see how the dirt work is coming along since they live out of state.

Good Saturday.

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You're in trouble... "... when loaded down."

Next time, "lightly loaded" :p
 
Took the 80 out to Utah this past weekend to do some camping with my son and the ole mut. Preferred to have AC in the 100 degree temps, so Pikachu stayed home for this one.

We camped in the Aspens at high elevation to escape the heat. These mountains are an island of damp, cool weather in the middle of the hot desert.

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Met up with my brother and his girlfriend at their VRBO in BV on Tuesday and we made a plan to head up to Mount Princeton yesterday. This is a fun ride up this fourteener and I hadn't been up there in a few years. They are Land Rover folks, so they were in the LR3. It made it up and back with no major breakdowns.

We had a great time. Always great having family around. My brother and I have grown closer over the last few years since our Dad passed in 2021. Always great to hang with him when I can.

He sure was enjoying the scenery:
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Great trail through the Aspens, with the peak in sight.
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Almost to the top.
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Great views to the north (towards Leadville and Twin Lakes) and east (Pike's Peak area) from up here.
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Heading back down.
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Oh, and an honorable mention to the poor sap in the AWD Sienna who realized he'd bitten off more than he can chew on the first half mile up. He backed over a quarter mile until he attempted to turn around in this spot.
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