Water pump/impeller housing pitting

Thoroughly degrease it, to get all trace of oil & coolant residue. I'd use parts cleaner followed by brake cleaner or lacquer thinner.

Fill the pits with JB Weld. Use your fiinger, popsickle stick, etc. to smooth it into pits in non-machined surfaces. IJB Weld will tend to flow some, so have the filled surface as horizontal as possible to keep it from flowing. If necessary, fill an area, let it cure, then rotate the part so the next pitted area is horizontal fill it & let it cure, repeat as necessary.

If the JB Weld starts to thicken/kick over, it won't smooth out. Time to mix a fresh batch as it won't adhere properly either.

If there are pits in machined surfaces like the impeller mating surface, save them for last. Use a freshly mixed batch of JB weld & a plastic putty knife to smooth it into the pits, with as little as possible extending out onto the machined surface.

If necessary, hand file/sand the JB Weld after it's cured.

Let it cure for at least 24 hours. Then, to inhibit future corrosion, coat the inside with either Glyptol or POR15. A couple of coats is better than 1 heavy coat. Do not coat the impeller mating surface, or gasket/o-ring sealing surfaces as the tolerences for them are pretty tight.

POR15 adheres best to slightly rough surfaces. If possible lightly sand blast the surface before applying it. Mask off machined surfaces so they don't get blasted.

 

Pitting/cavitation/corrosion is usually caused by running with pure water or a rubbish anti-freeze. A good anti-freeze contains corrosion inhibitors which really do the trick, or you can use water with a corrosion inhibiter and no anti-freeze.

 

I only run about 25% glycol based anti-freeze with the balance distilled water in my 308. I also run a bottle or two of corrosion inhibitor/water pump lube/water wetter found at NAPA. It's called NAPA Kool.

The JB Weld was my first thought also. You don't want to "blow" through the housing when you are driving. Bad and messy!

Try and get your clearances consistant and as close to factory as you can.

Try Zerex G-05 anti-freeze. It is free from nitrils,amins and phosphates. These can react with minerals in the water. Better yet, DON"T use tap water! Use distilled.

Another brand that I believe is NAP free is PEAK anti-freeze

 

WTF??? You can buy a complete rebuild with out a core charge for around $350.00, WITH a usable core, you can find one on ebay for $199.00 plus a few bucks for shipping as some guy has been selling a ton of them for that price. Tell the 700 buck guy he is high.

 

Try to get the Zerex G-05. Recent reading idicates this is the direction anti-freeze is going. Currently compatible with Mercedes, BMW, Volvo, Diamler/Chrysler, Ford and most importantly, John Deere! I will be mixing it 50/50 in the BMW with distilled water.

Stay AWAY from DEXCOOL, the orange "long life" product used in GM cars. My mechanic/brother has seen the long term effects/results first hand. Not good.

NOTE!!! A thorough flushing of the cooling system inncluding heater cores is required to ensure there are no compatibility issues involved. No telling what they were running in there.

 

Yikes! This stuff came in my new Chebby pickup. Can you elaborate on his experiences as a result of long term use of this stuff? Is it worth a flush and switch to the zerex stuff @ 5,000 miles?

 

Accumilation of deposits in various nooks and crannies throughout the cooling system eventually causing "hotspots" in the certain parts of the engine block and heads. Do a Google on DEXCOOL and you will find the pros and the cons there.

I would consult a certified tech when changing to a different coolant. One NO-NO I read was not to mix silica based coolant with non-silica base. In all cases a total pressure flush should be done anyway.

I will be doing that on my recently purchased BMW this weekend (aluminum radiator core/plastic tanks). Lord knows what they had in there but it wasn't the cool blue BMW stuff it came out of the factory with.

The standard stuff also attacks plastic components used on many new cars, like plastic radiator tanks, making them brittle and crack.

 

It also came in my 96 Cadillac. Every three years I had it changed out and never had a bit of trouble. I don't care what the GM engineers say about long life-at three years the coolant is at it's life expectancy.
_________________________________________________________________F512M-FLAT, FAST AND FURIOUS

 

I appreciate the info. I will do some research on it.

 

[THREAD HIJACK]Hey Don!!! Are you guys coming to the FCA dinner tomorrow night?[/END THREAD HIJACK]

 

Here is a comprehensive article about the differences in the available coolants from Japan, Europe and the US.

http://www.findarticles.com/p/articles/mi_qa3828/is_200408/ai_n9453107#continue

COOLANT CONFUSION: It's Not Easy Being Green . . . or Yellow or Orange or . . .
Motor, Aug 2004 by Weissler, Paul

With so many different coolants out there, it's important-make that essential-to know what's safe to put in where, and when.

Lift the hood of a new Ford vehicle and you're likely to see a yellow coolant in the overflow jug and an interesting label on it. In pictorial language it says "Do not use orange coolant; yellow coolant is okay."


Sounds pretty straightforward, right? It isn't. Lift the hood of another Ford product (in this case, a Taurus with the pushrod V6) and you'll see that same label, but the jug contains orange coolant. Wait a minute. Something clearly is very wrong. It cautions "don't use orange," but the factory-installed coolant is orange.

Lift the hood of a Chrysler product and you'll see orange coolant in the jug and a "special engine coolant only" warning on the cap. Isn't DexCool the special coolant, and isn't it orange? Yes to both questions, but Chrysler Group says don't use DexCool in its products. It's confusing, to say the least.

The basic answers to what coolant to use where, and when, are pretty simple, but when you go past that, you're getting into some pretty complex territory. And you have to know what coolant you're dealing with to be sure you're doing no harm.

Longtime MOTOR readers know that the color of the coolant dye really is meaningless. Dye should help you spot a leak, but that's about it. But with these seemingly contradictory warning labels, you really need a basic understanding of what's been happening with coolant formulations and colorings.

You may remember that about 93% of most coolant is ethylene glycol, another few percentage points are water and/or a solvent to keep rust/corrosion inhibitors in solution and the remainder are those inhibitors. The inhibitors make a huge difference, and they're what all the arguments are about.

Didn't we talk about all these coolants last year? You bet, and we'll probably be talking about them for years to come. Since last year, however, Honda and Toyota have moved strongly into extended-life organic acid technology (OAT) coolants. Yes, DexCools also are OATs, but these Japanese formulas are not DexCool, and the two car companies have indicated they absolutely, positively don't want DexCool-type coolants used in their vehicles.

Nevertheless, you have to pick something to install, and to top up with, and we've learned that the systems are not necessarily forgiving of some mixtures of different coolants. There are circumstances where an unfavorable mixture can cause an increase in corrosion.

Taking these issues a step further, this year we've seen more cases that contribute to coolant confusion. These days, it's all too easy to make a mistake.

You have to appreciate a bit of chemistry about the various formulas. You've got to know in basic terms what's different about the different coolants-both conventional and extended-life types-and what it means when you have to pick one. Yes, that includes a bit about the dye colors.

What's In DexCool?

You should know that the term "orange coolant" has come to mean a DexCool-approved brand but that doesn't mean it's really true. If you make this assumption, you'd be wrong. It's what Fords warning labels could be interpreted to refer to, so that label doesn't serve to clarify things (certainly not when a Ford system contains a very different-non-DexCool, but orange-dyed-coolant). The discontinued Mercury Cougar was an exception; it did contain an orange coolant similar to DexCool.

The "DexCool" designation means the coolant passes General Motors performance testing. Although DexCool is not a specific formula, all three brands that have the label (Texaco Havoline, Prestone Extended Life and Zerex Extended Life) are somewhat similar. In particular, they're OAT coolants, but the similarities go beyond that basic description.

All DexCool-approved coolants to date use two organic acid rust/corrosion inhibitors, one called sebacate, the other called 2-EHA (which stands for 2-ethylhexanoic acid). These organic acids are very stable and last a long time, although they take thousands of miles to become fully effective in protecting coolant passages.

GM recommends a DexCool change every five years or 150,000 miles, whichever comes first. Because most people drive 15,000 to 20,000 miles a year, that translates to a five-year replacement interval. As noted, the thousands of miles required to protect metal is an important trade-off for that longer life. Although like conventional coolants, OATs also contain other inhibitors, for targeted protection.

The inhibitor 2-EHA works well in hard water and is more effective than sebacate at lower pH levels (when the coolant moves from the alkaline end toward the acid side), particularly for cast iron. Well, GM has a number of cast-iron engines. When there's a low coolant level in the coolant passages, the exposed cast iron rusts. Apparently, that rust is washed away later by flowing coolant, and is deposited in the heat exchangers. It eventually produces the rust powder problems that have been so widely observed (see MOTOR's August 2002 issue at www.motor.com). Why does the coolant level in these engines drop? The original radiator cap design was blamed for some of the issue, but there probably are a number of causes, including owner neglect and normal seepage. However, the rust powder issue is not a problem that was observed with the previously used conventional American coolant.

The inhibitor 2-EHA poses another issue: It's a plasticizer (softens plastic), so it has been blamed for coolant passage gasket leakage. Softening (and the resulting distortion) was reported by Ford, which encountered gasket leakage problems when it tested a DexCool-type formula on its V8 engines. Ford also saw similar issues with other gasket materials. That killed the OAT coolant idea for Ford, which had used a DexCool-like coolant in the '99 Cougar V6.

Could that inhibitor be responsible for the intake manifold coolant gasket leakage on GM 60° V6 engines? Or is there some other service issue involved? (After all, GM isn't the only one with coolant gasket leakage problems.) The experts are still working on it.

What Preceded OATs

Until the extended-life OATs came on the scene, there had been primarily two major coolant inhibitors for aluminum protection-silicates and phosphates-and conventional American coolants have used formulas containing both of them. Silicates are related to sand, and there were questions as to their effect on water pump seals. Some old tests seemed to suggest they were harmful, but there has been no credible evidence to support that stance on late-model designs with reputable brands of coolant. In fact, today's carbide seals are about as durable as you can get, and silicates that remain in solution seem to produce no problem anywhere. In real-world evaluations, there's no evidence of any issue, as silicate inhibitors have been used successfully for many decades in all makes of cars. Where a seal-deterioration issue surfaces, it has been attributed to core sand, from failure to clean engine blocks properly.

Silicates protect very quickly, so if there's some mechanical breakdown in the silicate protection, it re-forms very rapidly. For example, a water pump may suffer cavitation erosion/corrosion (a high coolant/ambient temperatures issue, particularly with certain cooling system designs). That means that as the coolant passes through the pump, bubbles are produced, which then collapse with explosive force, pockmarking the internal parts of the pump. That pockmarking is erosion, the marks being exposed, unprotected metal. If the inhibitors work quickly, the damage stops after minor corrosion. If they work slowly (as with organic acid inhibitors), the pockmarked areas corrode for a longer period.

American conventional green coolants use doses of both silicates and phosphates. Phosphates also protect aluminum quickly, but have raised concerns in hard water. OAT coolants contain no silicates and no phosphates.

European coolants also contain no phosphates, but do contain silicates (at a somewhat lower dose than conventional American coolant) plus other inhibitors. These have been used for a long time, and although they're conventional formulas, there are enhanced versions today, as covered in the section on "Other Extended-Life Coolants."

Japanese conventional coolants contain no silicates, but they do contain phosphates for fast-acting protection, plus other inhibitors. Extensive Japanese tests have shown phosphates to be a good corrosion inhibitor for aluminum, and particularly effective in protecting water pumps from corrosion after cavitation erosion/corrosion.

The questions about 2-EHA were raised not only by Ford (and reportedly DaimlerChrysler) but within Japanese coolant development circles, as well. When Honda introduced its long-life coolant, it specifically excluded 2-EHA, and we can tell you there is unhappiness at Honda regarding DexCool in the new Saturn VUE with the Honda-supplied 3.5L V6. The system is being filled with DexCool because that's what s in the plant for everything else. It would not be simple to set up a separate coolant fill system for the Honda engine.

We can't tell you how this dispute is going to play out, but you do have to make a choice when it's time to change. The engine already has been protected with DexCool (unless there's an assembly line change in the works) and it's reasonable to install that when you service that engine. However, to extend gasket life and protect the water pump impeller and chamber, it wouldn't be a terrible idea to flush the system and switch to a coolant with phosphates and/or silicates (conventional American or G-05) at this point.

Other Extended-Life Coolants

Ford and Chrysler Group use G-05, a low-silicate, no-phosphate formula long specified by Mercedes, even for its passenger car diesels. Once a similar formula even was made by Texaco for Saturn, with green dye and carrying a 3/36 service interval. Today, the Ford and aftermarket versions have yellow dye-or at least they're supposed to. And the Chrysler Group formula has been dyed orange. Now that we've seen Ford products with orange, it's possible that some of the stuff meant for Chrysler also is being shipped to Ford. Or perhaps it's the DexCool-like coolant used in the old Cougar, although that's doubtful. It's confusing, particularly when you see a "don't use orange" label on the coolant jug and there's orange coolant in the jug.

What is G-05? It's called a HOAT (for hybrid organic acid technology) that today serves for extended intervals, typically 5 years/100,000 miles. Like conventional Euro coolants, it's a low-silicate, no-phosphate formula designed to pass European hard water tests. The reference to OAT in HOAT is for an organic acid inhibitor called benzoate, which actually has been used for many years in almost every American, Japanese and European conventional coolant except what we now call OAT.

Honda and Toyota use a new extended-life OAT coolant-made with sebacate as the only organic acid-no 2-EHA. Sebacate isn't quite as effective in combating corrosion at lower pH levels, but because that's more of a cast-iron issue, it apparently didn't concern the Japanese. Both Honda and Toyota do continue to avoid silicates, but add a dose of phosphates to provide fast-acting aluminum protection, particularly to recoat the water pump after cavitation erosion/corrosion.

What to Use

We used to say that maintaining the coolant level was more important than which type of coolant to use. But there's new evidence that we've been too cavalier in that respect. Sure, for small top-ups or in an emergency situation, it doesn't matter-use what you have. However, there are possible problems with extreme mixtures. An example cited by one coolant chemist: A somewhat diluted mix, perhaps 50% to 60% water, with the remainder (from top-ups) a 50-50 combination of an OAT and a conventional American coolant or a G-05. A remaining inhibitor (borate) could attack aluminum if the silicates are depleted. This becomes more of an issue when a part is being changed, and that new part has no protection against cavitation erosion/corrosion.

Top up with DexCool in GM and VW/Audi vehicles, and '98 Chrysler L/H cars or the '99 Mercury Cougar, if you get one with the original coolant or DexCool. Top up everything else with your second coolant-G-05 or conventional American.

Replacement Parts

Original equipment coolants are validated for factory replacement parts. One of the issues that may arise is the use of an aftermarket replacement radiator or heater core made of copper-brass with lead solder. We have in previous articles pointed out that today's coolant inhibitor packages contain a small amount of copper-brass protection, but may provide little protection if a radiator is made with high-lead solder. Results of industry standard tests of the new Toyota extended-life coolant now show a substantial weight loss (corrosion), both in a 50-50 mix aud in a 33% coolant mixture (solder corrosion is much greater in this more diluted solution).

If you have to change a radiator or heater core, use aluminum. Or, if it's an older car and the owner wants the lowest-cost radiator, you might procure a soldered-together copper-brass unit. Conventional American coolant should provide better protection against solder corrosion, which can result in radiator tube restrictions and leaks. But no coolant provides perfect protection.

If you're replacing aluminum parts on an engine, such as a water pump or even a new cylinder head, remember that part's coolant passages have not been protected. In those cases you should perform a complete coolant exchange.

Complete Coolant Service Choices

Chances are you'll standardize on two coolants to cover most situations. One will be a DexCool formula; the other could be a G-05 extended-life or a conventional American (green or gold). A better approach would be to have all three coolants. When it comes to what to use and when, here are recommended or suggested strategies:

GM and VW/Audi vehicles. For these applications, use DexCool because that's in accordance with factory coolant formula recommendations. Sure, the vehicle probably will be out of warranty by the time you get it and have to make a decision. But the OE recommendation is the safe way to go, and because you can easily obtain a DexCool, it's a no-brainer.

Ford and Chrysler vehicles. Here again, it's a no-brainer. Both companies have identified problems with DexCool, so use something else. G-05 is available in the aftermarket, so that's your choice for extended life on vehicles from those makers. However, if your second coolant is conventional American, that's fine. The recommended service interval is shorter, but if the coolant level is maintained and the motorist is not a high-mileage driver, it can serve beyond two years. In fact, Ford long recommended four-year intervals with conventional American coolant.

Japanese vehicles. This is a problem area, because Japanese-spec coolants have never been sold in the U.S. aftermarket and history says conventional American coolants work well in these vehicles. Toyota research indicates the new extended-life coolant contains phosphates to protect the water pump, and DexCool contains no phosphate. Honda has said it will not use a coolant with 2-EHA. So both carmakers exclude DexCool. Best solution with aftermarket coolants: Do a complete coolant exchange, and replace the Japanese OE coolant-conventional or extended-life-with conventional American or G-05.

Coolant Exchange

Never before has the capability to do a complete coolant exchange been more important. Even if you're changing a DexCool system and putting in new DexCool, you want to get the system full, really full. A low coolant level is bad news, particularly with cast-iron engines. Even if the engine is aluminum, a low coolant level could mean engine-damaging temperatures and surely cause poor heater performance in winter. With today's smaller coolant capacities, the system doesn't have to be low by much for problems to surface.

If you're making a change in coolant type, such as any Japanese coolant to American green or G-05, you should get at least 90% of the old stuff out. The only way to do this and ensure a full system when you're done is with coolant exchange equipment.

A complete coolant exchange can be done manually, if you have a lot of time and infinite patience, plus a willingness to lose money on the job. In addition to the coolant exchangers already on the market, we've been seeing new ones designed to handle two or more coolants. They're a recognition of the many different coolants currently in use.

Whatever the coolant, remember the other half of the mixture is water. In hard water areas, always use demineralized water. Some coolant formulas are more tolerant of hard water than others, but that doesn't mean it's good for them.

Visit www.motor.com to download a free copy of this article.

 

Take note of the reference to "older" cars with brass/copper/lead solder radiators. 308's come to mind so I am more inclined to stick with a more traditional TOP QUALITY coolant in this case.

 

Great article, I really liked when I had access to read Motor at my leisure!

In case those that didn't read the article didn't catch Spasso's comment above... the article says that old brass/Copper/Lead-soldered radiators are best with green coolant. That's what's in my 308, and what will stay there!

 

JDUBBYA;
Here is another solutiuon to the "fill in the gap" problem. I have used on many occasions a product made by DEVCON. It is a two part mix and you must buy it for either steel or aluminum or brass or whatever metal you are using. After 24 hours it is machine ready. You can drill, tap, mill whatever you want to do and it is virtually a part of the original metal. I repaired an aluminum oil pan one time and it never leaked a drop. A friend of mine who was in the Navy said they used it to repair high pressure steam pipes on a temp. basis. I think you can get it through a Grainger outlet near you. If not PM me and there is a company in town that sells it, I will get some and send it to you. The product is fabulous. If you decide to use this follow the instructions precisely and you will have no problem.
_________________________________________________________________
F512M-The last of a spectacular series of vehicles and the "M" stands for MAGNIFICO!

 

Years ago I used DEVCON Plastic Aluminum, however, I haven't been able to find it for quite some time. So started using JB Weld instead. Have been quite happy with it.

If it's available, would also do the job. Is that what you're referring to?

 

So I did the flush on the BMW this Saturday with water filtered through a 2 micron carbon filter until everything ran clear (I am on nearly mineral free well water). Did the thermostat change. Filled with Zerex G-05 (almost clear in color with a tint of yellow), distilled water, fire up the car, everything looking good and............................................ what is that under the front end? Drip drip drip. I cracked the #^&*()&%#@@!%&* thermostat housing (plastic) while torquing it down.

Back apart it comes today.................................................aaarrrgggghhh!

 

Since my 308 conked out last month it's been one fire after another.

 

This thread has a couple of my tips, see the one about cleaining inside the nose before removing the inner bearing. It also has a link to a illustrated WP rebuild procedure in the 308 GT4 register:

308 Waterpump and same old questions
http://www.ferrarichat.com/discus/messages/256120/184361.html

I posted some additional tips in this thread:
Water pump 83 308QV
http://70.85.40.84/~ferrari/discus/messages/256120/282100.html

If your WP turns out to have a 1-piece seal, this thread will help:
308 Water pump seals?
http://www.ferrarichat.com/forum/showthread.php?t=34538&highlight=water+pump+409


The sharpest looking wp rebuild I've ever done was Birdman's, also used SS bearings & a commercial seal:

My way cool water pump![b/]
http://www.ferrarichat.com/forum/showthread.php?t=47191&page=2&pp=20&highlight=water+pump+mcmaster+powder