cooling system rust/sludge

[JoshT]

Ok about to do some cooling system work on my 99 Ranger.

Since being taken off DD duty a couple years ago it's been neglected a lot more than it deserved. I did yearly oil changes (truck never hit 5K in a year and I was putting in synthetic), checked tire pressure and had the rotated and balanced when due, and that was about it. Never used the truck much so I just forgot about checking stuff. Well I screwed up and let the coolant get too low for a little too long. Found this out when I got about 20 miles down the interstate over the weekend. Noticed the temp gauge starting to creep up so I too quick measures to get the temp back down and limped it home. After truck cooled off I popped the radiator cap and was greeted by a nice orange colored sludge. Really it was a nice looking color, were it not for the fact that it was the color of rust I'd think about painting my next vehicle that color. Unfortunately rust orange is not the color I wanted to see when it should have been neon green.

So right now the plan is to replace the following:

• New radiator
• New radiator cap
• New water pump
• New T-stat

New radiator is not much more expensive than having one cleaned around here especially when you don't trust the shop doing the cleaning, BTDT. Obviously new radiator gets a new cap. The engine has 175K on the clock, so no telling how much of that orange stuff is the water pump fan. Better to replace it while I have the radiator out and easy access. I know the T-stat works, but better to replace it than take a chance of that crud messing it up. Hoses aren't that old, definitely have less than 50K, want to say a lot less than that and appear to be in good condition. If they look rough when I get everything apart I'll reevaluate, but until then I plan to reuse them. I plan to install all the new parts, except the thermostat, so that I have full flow while flushing. Will flush the engine on the hose until it runs clear. Once it flushes clear I'll add engine flush which needs to be run in engine for 6 hours under operating conditions. That's roughly equal to driving to work for a week, so it works out well. Then I'll flush on hose until clear again. Install t-stat, another bottle of engine flush for a week (forgot I already had one on the shelf). Flush on hose again until clear. Test for a couple weeks and then refill with 50/50 mix. Keep a better eye on coolant level.

I know sounds like a lot, I just hope it'll be enough.

On to my questions:

1. Explorer 4.0L SOHC HD radiator is dual core upgrade for Ranger radiator right? If I'm going to buy new might as well upgrade.
2. Any recommendations on water pump?
3. Does anyone make a water pump gasket that does not require RTV?
4. Is there a way to fully drain the block and flush it out with a hose without knocking out a freeze plug? I've heard of some vehicles having a water jacket drain plug, does the 4.0L have one?

I know I mention a water hose a lot, but when finished it will be drained and filled with distilled and antifreeze or 50/50 premix.

 

[adsm08]

4.0 has no water jacket drain plug, but can get fairly well emptied just from the rad drain.

Run some muriatic acid through the system and then drain and refill with regular coolant.

 

[RonD]

You can pull out an easy to get to "freeze" plug, core plug, and replace it with a rubber expansion plug.

I would also back flush the heater core, easy to do and well worth the effort, I would do this after you have flushed the entire cooling system.

Determine which heater hose is the IN and which is the OUT, warmer hose is the IN.
Remove both hoses from their engine ends.
Point the IN hose down at the ground or in a bucket if you want to see what comes out
Hold garden hose to the OUT hose, medium pressure is fine, you can tell how clogged the core is by the flow.
If flow seems overly restricted you can blow out most of the water inside and then fill the core with warm water and CLR(or vinegar) mix, let it sit for 20min, then flush, check flow, repeat as you see fit.

 

[JoshT]

adsm , thanks for the quick reply. That's what I thought about the drain plug. As for the HCl I'd give it a shot on an old copper radiator, but I plan to replace the radiator with a larger dual core unit. I'd be too worried about the plastic and rubber to run it through the rest of the system.

Ron, thanks for replying as well. None of the freeze plugs are exactly easy to get to on thus truck. If one needs replacing it will be replaced, otherwise I'm not removing them. Thanks for the reminder to back flush the heater core, it will be done probably before and after flushing. This truck has heater valve so pretty easy to disconnect.

 

[JoshT]

Possible change of plans. I have known for a while now that the 99 is getting near the end of its time with me. Have wanted to get a fullsize truck, but was figuring I'd wait and build what I want after I finish building the 86. Well I think I spotted the replacement for the 99 today. An older gentleman that dad and I have known for years is selling his truck. Just happened upon it today at the employee sales lot at work. It's a 94 F-150 I believe it has a V8, not sure if it would be the 5.0L or 5.8L. It's high mileage at 205K but the guy takes excellent care of everything he owns. Thing is near mint for the age and miles. Looking at it the only things I see are that the rear bumper is tweaked and it needs tires, and there's a few stains where I can see the carpet, most of the floor is covered with vinyl mats. Called the owner and the only things he knows of that are wrong are radio doesn't work (I'd replace it anyway) and passenger side window switch is dead. He is asking $2500.

So what I am thinking right now is buy F-150. Put 32s from ranger on F-150. Fix cooling issues with Ranger. Put stock wheels and a set of used tires of the stock size back on Ranger and drop it back down to stock height. Sell Ranger for $3500 - $4000. That's also got me thinking I'll try to have radiator boiled to save a little dough, but I'll still replace the water pump and T-stat.