Topic: Coolant flush questions

[Groundpounder17]

I picked up my ‘82 pickup a few months back and it has ran really well although I have several things I’ve been checking off the list for maintenance.  A couple of weeks ago I noticed that the the cheap top radiator to thermostat hose had been collapsing.  I decided to go ahead and order a new radiator cap, new hoses, and new clamps.  I’m now about to flush the coolant and have a few questions.   I went ahead and replaced the cap already and that fixed the hose collapsing

My plan:
- Use irontite Thoro-Flush as directed
- Next drain the system, remove the thermostat
- Replace the thermostat housing housing; flush engine  block
- flush the radiator
- replace the cheap hoses and old clamps
- fill the system water and run for 1/2 hour then flush again
- refill with 50/50

I saw that someone gave advice to just run just water for a week then install the thermostat and add 50/50.  That seems excessive and dangerous to me. I wouldn’t want to run for an extended time without the thermostat. Thoughts?

Also my truck has 3 hoses. Should I leave the middle hose going to the water pump in place when flushing the block or just remove all hoses and divide flushing the block into two parts?

Lastly, do I need to replace the thermostat or just rerun the old one? Do I need to grab a Toyota one or just get it at one of the autoparts stores?

[Snowtoy]

I would just go with the directions on the flush bottle.

Due to not knowing the age of the current t-stat, I would go ahead and replace it with a new Toyota one, and not a parts store one, most end up with coolant temp issues running a parts store t-stat.

[Groundpounder17 [OP]]

I would just go with the directions on the flush bottle.

Due to not knowing the age of the current t-stat, I would go ahead and replace it with a new Toyota one, and not a parts store one, most end up with coolant temp issues running a parts store t-stat.

Thanks Snowtoy.  The instructions on the bottle are just for flushing the radiator. While I’m at it I want to go ahead and do an engine flush.  I always prefer Toyota parts but my local dealer sucks and they have to order one plus they are way overpriced.  I usually always just order from McGeorge Toyota but it takes a while to get here.

Since it looks like I’ll need to order a thermostat should I go back with the original or should I get the 2 stage they offered on some later models?  Also mine has the paper gasket so do I need to just order that gasket or will I also need to order the rubber as well?

[emsvitil]

I just spent a week flushing out the cooling system on a Ford Focus..............

First 3 flushes I captured and just did a idle warm up.     (Then took anti-freeze to hazardous waste)

Then I'd fill with water, drive a day, drain at night; for 3 days.   (I'd just dump the 'water' on a bush)

Then I added the flushing chemicals and did 4 hours of driving.

Then 4 more water flushes.

Then compute how much full strength anti-freeze I need to get 50/50 mixture given cooling capacity.  (there's always water left in the block, so 50/50 will be diluted).      Top off with water.

[Groundpounder17 [OP]]

I just spent a week flushing out the cooling system on a Ford Focus..............

First 3 flushes I captured and just did a idle warm up.     (Then took anti-freeze to hazardous waste)

Then I'd fill with water, drive a day, drain at night; for 3 days.   (I'd just dump the 'water' on a bush)

Then I added the flushing chemicals and did 4 hours of driving.

Then 4 more water flushes.

Then compute how much full strength anti-freeze I need to get 50/50 mixture given cooling capacity.  (there's always water left in the block, so 50/50 will be diluted).      Top off with water.

The first three flushes I take it you only used water?

[Snowtoy]

models?  Also mine has the paper gasket so do I need to just order that gasket or will I also need to order the rubber as well?

It looks like Toyota offers just the one now, 90916-03078 replaces 90916-03076, which I believe is the original part number for your '82.

Based on the diagram here, it looks like your '82 uses both gaskets.
https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-engine-coolant-thermostat-9091603078


$30+ shipped is about right from the dealer, I think I paid about $20 for just the T-stat alone for the last one I bought from my local dealer, and $4 for the rubber gasket.  It looks like RockAuto now sells AISIN parts as well, might order one and see what it looks like.
https://www.rockauto.com/en/catalog/toyota,1982,pickup,2.4l+l4,1277153,cooling+system,thermostat,2200

[Groundpounder17 [OP]]

It looks like Toyota offers just the one now, 90916-03078 replaces 90916-03076, which I believe is the original part number for your '82.

Based on the diagram here, it looks like your '82 uses both gaskets.
https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-engine-coolant-thermostat-9091603078


$30+ shipped is about right from the dealer, I think I paid about $20 for just the T-stat alone for the last one I bought from my local dealer, and $4 for the rubber gasket.  It looks like RockAuto now sells AISIN parts as well, might order one and see what it looks like.
https://www.rockauto.com/en/catalog/toyota,1982,pickup,2.4l+l4,1277153,cooling+system,thermostat,2200

That’s the parts I was looking at but I was looking at a different diagram.  In some of the later models Toyota also offered a 2 stage thermostat that I know of at least one person running, part # 90916-03070.   Some of the engine shops also sell this one as an upgrade, but I’m not quite sure how it’s an upgrade or what the purpose is for switching.

[Snowtoy]

Found the t-stat for $19 on Walmart.com, with free shipping.

Not sure what issue the upgraded one is meant to resolve, haven't ever had an issue with the oem one in 115* CA valley heat or single digit temps in the winter, it looks like it has a mini-T stat built in.

[emsvitil]

The first three flushes I take it you only used water?

Yes

Leave the thermostat in.     Hot water cleans better.     Flush with old thermostat (and water pump if you'll be changing that too)

[Groundpounder17 [OP]]

Yes

Leave the thermostat in.     Hot water cleans better.     Flush with old thermostat (and water pump if you'll be changing that too)

Thanks, emsvitil.  I plan on rebuilding my engine in the next year so I think I’ll just do the flush for now, but I will go ahead and have a new thermostat on hand in case I need it. When I rebuild then I’ll replace things like the water pump

[Groundpounder17 [OP]]

Found the t-stat for $19 on Walmart.com, with free shipping.

Not sure what issue the upgraded one is meant to resolve, haven't ever had an issue with the oem one in 115* CA valley heat or single digit temps in the winter, it looks like it has a mini-T stat built in.

I couldn’t figure it out either. I’m going to go ahead and order a stock one