I'm going to flush the cooling system. While in there, I figured I may as well replace: radiator hoses, hoses leading to/from the heater core, thermostat, gasket, radiator cap, and all associated clamps. I want to make sure I do this all right, and in the right sequence. Here's my game plan:

1. Drain the system via the radiator petcock, then pull the lower hose and the two plugs in the block to make sure I get as much out as possible. Somehow drain the overflow tank.

2. Button everything back up. Fill the system with tap water from the garden hose and some sort of flush chemical.

3. Run the engine up to operating temp so that I know the thermostat has opened, or for however long the flush chemical recommends. Heater on full blast.

4. Let everything get back to ambient temp.

5. Repeat Steps 1-4, but only using distilled water. Repeat as many times as necessary until water coming out shows no signs of flush chemical. Drain per Step 1.

6. Remove and replace everything that is going to be replaced.

7. Button everything up, then drop in 4 gallons of Fleetguard or similar.

8. Top off system with distilled water.




PLEASE feel free to critique this sequence since I've never done an actual flush before. Some additional questions I have:

1. Is there a preferred flush chemical or one to stay away from? I've read that using Cascade, Dawn, or Simple Green does a pretty good job as well, provided it gets flushed thoroughly.

2. I'm assuming the risk of cavitation for the short time I'll be running just on water is minimal, yes?

3. Worm drive clamps, or re-use the originals?

4. Anything else to replace while I'm in there?

5. I know it's highly recommended to replace the t-stat with OEM only, but what about the radiator cap? Or should I not even bother right now?

6. How do you drain the overflow tank?

7. Does anyone have pictures or a VERY SPECIFIC DESCRIPTION of the plugs in the block I need to pull?

As always, I greatly appreciate all the help!

Mike

 

personally, i wouldn't bother with the freeze plugs unless they're already leaking. but if you do, the standard method is to hit one side of them with a chisel until they rotate inward, then grab the outer side with vise grips and pull them out. new ones should be set in place, possibly with chemical sealant, and driven in with a drift and hammer. for a drift, a "bearing and seal driver kit" may work well, or a socket thats large enough to fill most of the plug's area.
as for which plugs, one on each side of the engine, its not too important its front-back position, as long as its one of the row that are fairly low on the block.
for the radiator, the most effective method is to remove it from the truck and use a garden hose to cause a water flow one direction, then the other, then the first, repeatedly until it only flows clear water. this should be done after you're done flushing the block. the heater core should be treated in similar fashion, but can be done in place.
new hoses all around are advised unless they're fairly recent. they don't hold much gunk, but a blowout is ugly, and hoses are cheap.
as for the risk of cavitation, the damage usually takes a number of years to eat through the block, so a couple hours of hot-cold cycles will be of no noticeable harm.
as for T-stat, as you read, OEM only. radiator cap shouldn't matter on brand, as long as pressure is correct. they're pretty simple.
for hose clamps, worm drive clamps (ideal, etc), are able to strip if you apply too much torque. be aware of this as you install them. a nut-driver is a good choice, a ratchet requires you to be careful not to over-torque. with new hoses, its always recommended to re-torque them after a couple of days. on my 87, the OEM clamps were also worm-drive, so no different from aftermarket. i would go with new.
for draining the overflow tank, 2 styles were common. one had a port on the bottom of the tank where the hose went, the other had the hose go through a hole in the top cover. in either case, remove the hose. in the case of the hose going through the top, a simple hand pump will start a siphon, or if its dirty, a garden hose nozzle will work wonders once the tank is removed and inverted (bottoms up)

--josh

 

Thanks for that. The plugs I was talking about aren't the freeze plugs, though. Allegedly, the block has two drain plugs built into it that can be removed to help get all the coolant out without having to flush a bunch of times.

Mike

 

If you use soap, use laundry detergent. It foams less and will be a lot easier to get out. You could run citric acid through the system but only if it is really dirty as in someone ran straight water for a few years.

 

combine steps 7 and 8.
7. Button everything up, then drop in 4 gallons of Fleetguard or similar.

8. Top off system with distilled water.

pour in 1 gallon of each.now you have 2 gallons of exactly 50/50 in there,and two empty,clean 1 gallon jugs so you can mix 50/50 before you pour it in.this way your mixture is more accurate.

radiator cap = 13 lb.

 

Thanks for all the input! I'm leaning towards Simple Green as my detergent just because I'm generally a fan of it and buy it in Costco-size containers, so I have plenty.

Mike

 

My only worry to that method is not accounting for the water that may still be in the system from the flush, which would offset the 50/50 ratio. My thought to doing it this way is that I know the system is 8 gallons, so by putting in all 4 gallons of Fleetcharge (Fleetguard, whatever) and then topping off with the water, I should be sure to get the ratio right.

I picked up all the supplies last night. 20 gallons of distilled water is HEAVY! Probably overkill, but I figured it's cheap enough that, should I need to do a second flush with distilled to get all the tap water / Simple Green solution out, I can. The look on the grocery cashier's face was priceless, though.

I found the Fleetcharge at O'Reilly's for $16/gallon. They had to dig it out from the commercial counter in the back and it was covered in layers of dust, but whatever. I also picked up some new worm drive clamps. They had some new design that comes with thumb screws built in (I'm guessing to help ensure you don't over-tighten) but knowing my luck, I would just snap the damn things so I went with the old-school ones. And I just realized I forgot to get new ones for the heater hose. Crap. Back to the parts store I go!

Here's hoping tomorrow goes well.

Mike

 

I put the Fleetcharge in first like you mentioned. When I did mine, I didn't pull any block plugs so I knew there was still water in the system. If I were to do it again, I would do the same thing. The only tricky part is getting the reservoir filled. Maybe mix a gallon 50/50 and put it in the tank first and then follow the above procedure.

 

The "new design" is probably meant for people that don't have tools but want to try to fix something (or good for emergency fixes). Depending on where you put them, that could be harder to fit your hand in to tighten them. If its a plastic thumb wing, good chance that will break off and depending on whats underneath, they might lead to some real issues when they need to come off.

I don't know what the ones you picked up are, but I like to get the nice stainless steel hose clamps from Lowes. Chances are the ones on the truck are probably reusable, unless the screw is rusted up.
Also, some of the originals have metric heads, so grab for the metric nutdrivers (less chance of slipping off than screwdrivers)

 

i like the Ideal brand clamps, just standard and simple, no thumbscrew or anything fancy, just simple stainless steel.
most hose clamps use a 5/16 (8mm), though 7mm and even 6 are sometimes used, and smaller clamps are often 1/4". a screwdriver should only be used when a nut driver//socket absolutely can't be used for whatever reason

 

Yep, I buy the same hose clamps. I get the 10 pack because I always need hose clamps.

 

In the middle of the job now. Man, does it take forever for a diesel to get up to temp!

Quick question on the cap......... Should I leave it on or off while idling the system? It's on right now with the burp tank loosely installed. Waiting for the t stat to open because it didn't take anywhere near as much water as came out, I think. Burp tank is filled with water. Hoping it'll suck some in.

 

So, kinda answered my own question. Truck was taking forever to heat up, so I went to take a quick trip around the block. I got to to the first stop sign when all hell began to break loose. Guess the t stat finally popped open and sucked what little water I could get down her throat. Got her back and shut down before anything bad happened. Waited a bit for her to cool before I opened the cap, and the rad was bone dry. Filled with tap water and idling now just fine. Really dodged a bullet there!

So, I guess to get all the fluid in, you kinda have to do the job while it's hot?

Mike

 

i cheated and skipped to the bottom heh. But you can pick up a 'T' that goes in the heater hose that lets you hook a garden hose to it. Drain rad. hook up garden hose and crank it on leaving the rad cap off, start it up heater on, walk away for 15min and youre done. It goes in the heater hose because the heat circuit bypasses the T-stat and circulates through the block. As far as the overflow, if youre over meticulus like myself, its a 1-3 screws and it comes off and you can dump it out.

The tee i speak of can be had from autozone, thats where i got the last one, Prestone brand offers it. They also have coolant system cleaners that can be added to current anti-freeze to clean pre-flush. Also the tee comes with a cap so it can just be left in the system. Oh, and make sure you put the tee in the "to heater core" hose from the t-stat head otherwise it will bypass the heater core. Another good thing to do is blow the radiator out real good with compressed air, it'll amaze ya how much dirt and dust is trapped in there. Blow it, wash it blow it to be thorough.

Hope this helps ya out some and save some time. Mike

 

Done! Skipped the t-stat install (rest of the job was taking too long), but got the radiator and heater hoses swapped out. I was hoping to use the old hoses as emergency spares, but all the hoses were so fused to their spouts that I had to slice 'em with a razor blade to pry them loose.

In the end, I ended up using Simple Green (about half a spray bottle's worth) as the cleaning additive. The system wasn't overly crudded up, but it seemed to do a decent job. After, I only did one rinse cycle using only distilled water. I was prepared to do more, but the water wasn't super foamy, which told me I had gotten most of the Simple Green out.

The burp tank ended up being super easy. I don't know if it's right, but mine's not really bolted in per se. Instead, it's held in by a metal strap that goes over it, so I just disconnected the strap from the fender and wormed the tank out. When I was finished with all the flush cycles and ready to fill with coolant, I mixed a gallon of distilled water with a gallon of antifreeze, then poured to the fill line. I poured the rest of that mixture down the radiator, poured in the remaining 3 gallons of Fleetcharge, and then topped with distilled water.

I am curious if there is a smarter way to fill the system when cold. After my little scare, when I was filling I would: top the radiator, start the truck, let it suck in all it would while topping it off, throw the cap on, then watch the temp gauge. As soon as it started heading higher than 'O' (something mine normally NEVER does), I'd take the radiator cap off (CAREFULLY!!) and top the system off again. I get what's going on (t-stat opens and sucks everything out of the radiator into the block), but is there some smarter way to do this with the t-stat in place?

Glad to get it done, though. No cavitation worries for me! Now I just need to pick up the test strips and a bottle of SCAs to keep everything in check.

Mike