Flushing cooling system with bad water pump

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So I bought a 2003 Chevy 2500 referenced in this thread here. The cooling system is questionable at best. Meaning the overflow has some gooey stuff in the bottom. It needs a water pump but I also wanted to flush the cooling system. So the issue is, as soon as I pour anything into the bottle it comes right out the weep hole in the pump. My plan is to swap the pump over, but not the new hoses, maybe even guy the t-stat housing that is in there and run it with no t-stat. Then flush the system with a cleaner, I have the Liquimoly stuff as well as citric acid. Then install the new hoses, t-stat, new reservoir, cap, and fresh coolant. The truck came with a free Gates pump, lien sale so I got other interesting things as well. If the flushing takes out the pump I will get a AC Delco one. I already have new belts, tensionors, and a 145amp alternator.

So what does everyone thing about the plan? It is a bit extra work, but I want to do this sort of correct.
 
That's pretty much how I'd do it. My last flush I did on the Buick with distilled water and I took the thermostat out to speed the process up
 
Thanks to Trav, I learned that he uses 1 lb citric acid per gallon of distilled water. I mixed prior to adding to cooling system. I also removed the thermostat during the flush process. And I got a little more (BITOG radical)?
I purchased a 110v electric water pump meant for RV use from eBay, an 1 1/2" X 1 1/2" X 5/8" Tee from etrailer sales and spliced it into my lower (intake) radiator hose and feed from a 5 gallon bucket. I adjusted the pump pressure down to 17 psi so as not to explode my cooling system. I bought a couple 1 1/4" plumbing test plugs; plugged the disconnected top radiator hose and set up a 3/4" hose to drain from the thermostat output housing, I started the engine, used my electric pump to maintain a flow of distilled water thru the engine and let it drain (thru the thermostat output) and my connected hose into another bucket until it ran clear.
I admit that with my pump purchase, fittings, hoses, clamps, 27 gallons of distilled water, etc., I've spent about the same amount of money as a wallet flush at a dealer, but now I'm all set to do it next time (with additional fluid purchases).
 
Your plan sounds good to me. The new pump won't mind the crud it's circulating, you're just using it to your advantage. As long as you do a full and complete flush, the new pump will be fine when you're done.
 
Throw the Gates pump on, and then do a cleaning cycle with dishwasher detergent or a similar alkaline detergent with low foam to get rid of the grease and oil in the cooling loop, rinse with water, then citric or oxalic acid to get rid of rust and scale. One school of thought is to use a sump pump to move the cleaning solution and rinse water for as long as possible without running the engine.

I wonder if the LSx-based Vortecs are as prone to IMG failures as the older ones too. I think Fel-Pro has a stainless steel and FKM gasket for those too.
 
Originally Posted by 14Accent
Your plan sounds good to me. The new pump won't mind the crud it's circulating, you're just using it to your advantage. As long as you do a full and complete flush, the new pump will be fine when you're done.

These are my thoughts exactly.
 
Originally Posted by bdcardinal
The truck came with a free Gates pump, lien sale so I got other interesting things as well. If the flushing takes out the pump I will get a AC Delco one.


My thought would be to throw the Gates water pump into the scrap bin and use an OEM or at least a ACDelco professional water pump, but that's just me, I guess.
 
Attacked the job last night. Obviously there is an oil leak somewhere. I got everything cleaned off as much as possible and got the new pump mounted. I used new bolts from ICT Billet for the water pump. Also got the new 145amp alternator mounted. I got the ACDelco, actually Gates, HD belts as well as new ACDelco tensionors and idlers, which had Gates paperwork in them as well. There should have been 4 clips holding the fan shroud halves together, but there were only 3 and all were different. I got the new belts routed and then called it a night. I was fighting darkness and an unhappy back. When I get off of work today I will try to finish the job tonight.

As far as cleaning the timing cover, I used a combination of brake cleaner, brushes, a MATCO scraper, and Motorcraft Metal Surface Prep Wipes.

Also the Y shaped heater hose broke right at the Y fitting when I was taking it off the old pump, not really ideal for my plan. Also there was some yellowing looking coolant that came out when I opened the floodgates. Still debating how this will all go.

Also of note, whoever was in this before does not understand that host clamps come in many sizes. They just used the giant ones and the tails were hanging out cutting up my arms in the process.

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Definitely advocate for the Citric Acid approach mentioned by Trav. Worked wonders on my Caliber.
Looks good what you've accomplished so far, look forward to the end of the story.
 
Originally Posted by Fifth87
Definitely advocate for the Citric Acid approach mentioned by Trav. Worked wonders on my Caliber.
Looks good what you've accomplished so far, look forward to the end of the story.


Found this at work. I remember buying it for service years ago and it hasn't been touched since.

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What's the saying, 1 step forward, 2 steps back? So I went to pull the heater hose connectors off to replace them, and of course they fell apart. Good news, I was smart and ordered new ones. Bad news, I am really good at Ford and Mazda parts and not GM, got the wrong ones. So those will be in on Monday. I put the new overflow bottle in, so that went well.

I then decided to change the spark plugs. That wasn't too bad, except the wires fell apart taking them off so I had to dig those off. I ordered the 748HH wires that are supposed to be 10.5" but I think they were missboxed. They were shorter than the ones I took off the truck and those were really tight between the coils and wires. O well, ordered more for Monday.

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Got it all back together tonight, filled with just water to get it burped. It looked good so I added a bottle of the Liqui Moly radiator flush to start cleaning. The heat was really hot, and the AC was really cold, so that part was great. Then I noticed a drip under the truck. Checked further and it was from where the thermostat housing goes against the water pump. Shut the truck off and let it cool a bit, then went to check the bolts. The bottom one was loose, went ti snug it up with a short 1/4" ratchet and got tight, then loose..... At least I am really fast at taking it all apart now
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Going to get an ACDelco pump and hopefully get it all together tomorrow.

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Got the new/updated/latest and greatest pump in today from my Motorcraft/ACDelco vendor. I already had the updated t-stat. Hopefully all goes well tonight.

Lesson for anyone reading, when you do something like this, fill it with water first, you can always drain the water and put in the coolant later.

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It runs!!! No leaks. I just refilled with water for now. Changed the oil too. Going to drive it a bit and then will drain the water out of the radiator and will see how it looks.
 
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