Coolant Expansion Tank

[dmj291]

Hey guys new to the forum & IDI's. Anyways looking for a replacement coolant expansion tank, mine cracked along the bottom driving home today. From a couple google searches & reading a few other threads, looks difficult to find an OEM replacement tank. Can anyone give me a universal p/n that works with washer bottle bracket & has adequate capacity? Otherwise.... may be going the milk jug route

 

[Fixnstuff]

Mine also cracked on bottom only about 1-1/2 inch crack. I was slowly losing coolant from the radiator and worried about that. I removed the expansion reservoir to get better access to remove power steering pump when I found the crack- also found underneath the missing 1/2 of the broken cap. They are on my kitchen floor waiting to be cleaned and prepared for a 2 part epoxy glue fix. After 28 years it seems to be brittle so I would like to replace it with a new one.

1987-1991 should be identical if not other years as well. Mine has a small hole in the top of the tank next to the cap and a small hole in the center of the cap and I don't know if that is original or what might have been attached (overflow hose in the cap?) Does yours have those two holes and whatever was connected to the cap? Overflowing onto the fender well insulation is not good.

Finding one close to the same size might work- using adhesive foam padding on the steel brackets to hold a smaller one in place. I might try that route when I have the time to search but for now it is patch it and use it.

I might have to get into solvent welding plastics and/or heat molding (on a bench) and welding thermo-plastics to modify one or make a new one. Seems like a very useful skill to have and fun too.

 

[Waystro]

Wonder if a tank from a 84 f350 351 would work.
I'll do a comparison tomorrow.

 

[DOE-SST]

I've plastic-welded cracked coolant tanks using a propane torch and junkyard tanks as the filler material. I cut up the junkyard tanks into thin long pieces, grind the cracks out to accept the filler, heat the cracks to just below melting, then put the torch to the filler pieces and let them liquefy and drip into the cracks. These repairs have held up for years. I use a heavy layer of RTV between the tank and anything it might rub against to prevent chafing and reduce cracking.

ETA...

there are a few tricks to my technique.

I. I use scrap tanks from the same model and year vehicle as mine, to help ensure the materials are the same.
2. I believe the tanks are HDPE, which requires heating up the cracks to the melting point to make them weldable. You cannot just drip liquefied material into a crack that hasn't been torch-heated. One solvent available today for cementing HDPE also requires preheating.
3. I don't allow the torch flame to char the plastic very much. I just keep the flame far enough away so the superheated air coming off the flame melts the plastic.
4. I also build up weak areas of a tank, like bolt holes using this method.

I've tried the harbor fright tool, but found it much slower to use than a propane torch. In a pinch, even a Bic lighter will work.

 

[Fixnstuff]

... Can anyone give me a universal p/n that works with washer bottle bracket & has adequate capacity? Otherwise.... may be going the milk jug route

My best suggestion (further below 'How to') is Fix It*

A Ford Dealership Parts Department should be able to look that part up for you, give you the Part Number and be sure to ask for the status of the part. It's probably not "Obsolete" status quite yet, so there is some very small hope that it might become available through Ford again by a back order but you have to ask those specific questions or the parts guy likely won't look deeper into it. Ask where you might find one too. That Ford part number would be referenced by anyone who made an aftermarket tank that would fit so that's the number you need. I HOPE you can find one.

I am just going to fix/patch mine for now and later fabricate a nice one out of stainless steel or aluminum with a sight glass in it. any metal as far as that goes, even soldered copper or brazed brass. Not that I want it to look like a race car or show car but those are materials I know how to work with. Plastic would be just fine with me and I am willing to make one out of any suitable material. You could even make one out of wood and put a bladder inside of it as far as that goes.

*I would suggest that you consider adequately fixing the one you have now and done right you won't have to be concerned with it for a long time. Heat welding the cracks and/(or) heat welding a plastic patch over the crack(s) is the best repair- Hot air is best for that or even using a cheap soldering gun style plastic welding tool would be good- I think I saw one of those at Harbor Freight for about $15.00. A regular soldering gun with a special flat tip would work also if you don't let it get too hot and you can also buy plastic welding rods for cheap at Harbor Freight.

Most important, clean the area very well, then very lightly grind scrape or cut off a very thin layer of the oxidized surface of the plastic in the repair area... dremel tool or whatever works. Then find the definite ends of the crack and drill a hole at each end so the crack will not continue to break beyond the holes. Then grind a groove or 'V' along the top of the crack so the weld material can fuse into each side of the crack rather than just covering it. Proper preparation of the the surfaces to be welded or repaired is a most important step to get a good repair. I am basing this advice on substantial education and AWS certifications in welding and welding/repairing plastics is very similar.

If you don't want to go to that extent and ASSUMING this is HDPE plastic you can buy a product in a tube called "Patch 'N Go" which will work quite well if you prepare the surfaces like I suggested. CANCEL THAT! I saw a YouTube video of a repair guy at a Kayak shop using it (incorrectly with almost no preparation of the repair area) and he suggested that it is a good product but upon reading details of the product in MFR literature it's not for that kind of repair or structural repairs so I won't recommend it. Other products may be good though, I don't have time to search for those now.
That company also makes patch materials but I'm not sure how good they are.

A roughened surface equivalent to using light grit sandpaper will provide a better bonding surface for any type of adhesion repair. Smooth shiny surface not good

There are lots of videos of these processes on youtube but very few from people who really know what they are doing - some pretend that they know but if they are not preparing the surfaces in at least some of the ways I mentioned above then they don't know much. - you can get the basic idea from those videos. A few professional videos promoting their plastics welding tools show some good techniques.

You might be able to find a local business (or person) that can weld/repair plastics- another option

 

[Fixnstuff]

Wonder if a tank from a 84 f350 351 would work.
I'll do a comparison tomorrow.

Thank you Waystro.

I wrote an extensive reply to this, what I searched through (hundreds of tanks) and what I found about possible interchanges (which was NONE) and lost that post while I wrote another one to the original poster, tmj291 who hasn't been back yet.

Too tired to try to re-write it but I might do part of it later. I don't think any out of gas tucks will be close to these.

Seems like a thousand or more unique designs. They are so inexpensive to manufacture that design consistency is not a consideration.

20-30 year old ones would be OK, IF one can be found but then they are probably old and brittle and prone to the same problems.

 

[Fixnstuff]

I've plastic-welded cracked coolant tanks using a propane torch and junkyard tanks as the filler material. I cut up the junkyard tanks into thin long pieces, grind the cracks out to accept the filler, heat the cracks to just below melting, then put the torch to the filler pieces and let them liquefy and drip into the cracks. These repairs have held up for years. I use a heavy layer of RTV between the tank and anything it might rub against to prevent chafing and reduce cracking.

THAT IS AMAZING! Much Credit to You! (I saved this reply for last) It inspired me to look further into welding plastics!

I learned that 2-part epoxy is probably not a very good repair (proper preparation and I think it would work) but plastic welding is better. Solvent welding is good too IF that plastic can be solvent welded.

Once I can confirm what plastic is used this will be solved for me. I just haven't taken the time to search for that information.

When I first read your comment I soon imagined having a huge pile of old overflow tanks in the back yard

I would have thought that the carbons in a propane flame would contaminate the plastic and not make a good repair- apparently not the case- technically perhaps but as far as practicality, not, so this is a really good option that I may well resort to because I can't afford to buy good plastics welding tools.

If I only knew what plastic is used to make these tanks it would be so simple. I think it is high density poly-ethylene which other comparable tanks are made from - like weed sprayer tanks etc. even Kayaks. One guy heat welded a steel screen reinforced patch on a Kayak using plastic strips cut from a 1 gallon Rain-X jug (HDPE plastic). On the bottom where the recycling triangle is located it usually tells what kind of plastic the container is made from so there should be no shortage of new plastic to use for patching strips or fill material.

I have two old trigger style soldering guns and one tip with a flat plate on the end which would be useful too if the guns still work.

I really appreciate the fact that you did that!

 

[Waystro]

Thank you Waystro.

I wrote an extensive reply to this, what I searched through (hundreds of tanks) and what I found about possible interchanges (which was NONE) and lost that post while I wrote another one to the original poster, tmj291 who hasn't been back yet.

Too tired to try to re-write it but I might do part of it later. I don't think any out of gas tucks will be close to these.

Seems like a thousand or more unique designs. They are so inexpensive to manufacture that design consistency is not a consideration.

20-30 year old ones would be OK, IF one can be found but then they are probably old and brittle and prone to the same problems.

Interesting I haven't spent much time looking at coolant tanks.
To the Op I have a Tank from a 86 diesel it held coolant with no leaks
But it's used. Shoot me a pm if you want it. I'm looking at this for my 85 since I want a clean engine bay.
http://m.mishimoto.com/aluminum-coolant-reservoir-tank.html

 

[Fixnstuff]

To the Op I have a Tank from a 86 diesel it held coolant with no leaks
But it's used. Shoot me a pm if you want it.

I sent a PM about an hour ago to the OP to advise him to see the new posts in his topic and if he is not getting notices to change his spam filter settings to allow oilburners.net and the admin email address which I also sent.

I'm looking at this for my 85 since I want a clean engine bay.
http://m.mishimoto.com/aluminum-coolant-reservoir-tank.html

That looks too small to me, not big enough to accommodate this 7 gallon cooling system. I found an image of one in a newer diesel truck that might be better- it's narrow and long and might fit along the fender where the original is installed. If yours is the same as mine, the existing hold down bracket (that the windshield washer reservoir is also mounted to), could be shortened, moving both reservoirs close to the inner fender and this would provide an (estimated) extra 6+ inches open space on the engine side which would be useful space.
I didn't look further to find approximate actual dimensions, nor the connection points on the tank (which probably won't matter) but I'll find it again later check further and post the information here.

 

[chris142]

Mine cracked too. Part# E7TZ8A080A is and has been obsolete from ford for years now. I talked to 2 dealers today.

Ford is only servicing cars and trucks 10 years old or newer. Once a car gets 10 years old the VIN# drops from their computer base. They cant even look up a part without the vin.

 

[dmj291]

Thanks for all the good info... well I bought a plastic welder from harbor freight for $17. Managed to patch it up with no leaks! Pretty easy.

 

[Fixnstuff]

Thanks for all the good info... well I bought a plastic welder from harbor freight for $17. Managed to patch it up with no leaks! Pretty easy.

WOW, that is great to hear, congratulations! Did you use plastic rod for filler material and if so was it polyethylene?

I think these tanks are polyethylene which has very high resistance to chemicals of all sorts- that is why it is used. That is also the reason why chemical adhesives don't work well and are likely to fail, they don't chemically bond to polyethylene- (very few exceptions which also require heat - the heat applied to the polyethylene changes the chemical structure enough to allow some chemical bonding with the adhesive).
I learned that from a technical document on polyethylene repair and also learned that heat from a flame (like a propane torch) can also be used and no concern for contaminants from the flame was mentioned!
Source:
http://www.polyprocessing.com/documents/Repairing-Polyethylene.pdf

I looked on the bottom of a common one gallon water jug (like a milk container) and it is high density polyethylene so this can be used for filler material and patches for heat welding.

You are new to IDIs so you MUST become aware of this!: The only coolants you can use in this engine MUST have SCAs in it to protect your cylinder liners from cavitation pitting! PEAK brand FLEET CHARGE SCA PRECHARGED is the easiest to find to be certain that you have the right coolant. The O'Reily/Kragen/Schucks parts store chain carries it or you can find it at farm supply stores. I get the undiluted version and mix it with distilled water. THIS is the label to look for and make sure it has the 'SCA Pre-charged on the label. (and see below the image):

You must be registered for see images attach

If you know the previous owner, contact him/her and ask if they used coolant with SCAs. If they don't know you might be at risk for having a coolant without anti-cavitation additives. The SCAs in coolant also diminish over time and the coolant needs to be tested once per year. You have two options then. 1) Get some SCA test strips, test the coolant and add the amount of SCAs needed or, 2) flush the system and replace coolant with the FLEET CHARGE SCA. Both of those options are a PITA (pain in the @&&) getting the right test strips and additive or flushing the coolant especially during the winter in Michigan. Cooling system holds 7 gallons.

I think with fleet charge you won't have to worry about testing with test strips, just always use it to top off the coolant.

 

[dmj291]

Yep.. plans are to flush coolant to fleet charge this weekend, change oil to 5w40 for the winter, and do the fuel filter.

 

[Fixnstuff]

Mine cracked too. Part# E7TZ8A080A is and has been obsolete from ford for years now. I talked to 2 dealers today.

Ford is only servicing cars and trucks 10 years old or newer. Once a car gets 10 years old the VIN# drops from their computer base. They cant even look up a part without the vin.

Hi Chris. They may drop VIN numbers from easy access (they are still in the computer system) and THEY DO NOT NEED VIN NUMBERS to look up parts! THAT IS A FACT. I've done this many times this year for my 87 model, even over the phone. When I go in they look up the part for my year and model 6.9L and the screen shows all of the related parts to that part of the engine and how they are assembled along with the part numbers. They always print this out for me unless I tell them I don't need it. I usually deal with the parts manager who has been there for over 30 years but the other guys have done it too.

Not servicing vehicles after 10 years? HA! Drive a 20 year old truck to the Service Department, sign on the line for $1,000. plus repair and see how fast they come up with the parts and fix the truck!

Normally a part is not "obsoleted" until 20 years and some parts longer than that. I know this for a fact also. The VRV I want that controls the vacuum to the C6 is well over 20 years old (28 yrs) and has been on backorder by Ford Motor Company all of this year while they have been negotiating with a supplier to make more. If/When the negotiations fail (which is likely due to low demand, so little incentive for the maker to set up again to make the part) THEN the part will be obsoleted by Ford.

The good news is, you can fix the one you have or find an alternate.

 

[chris142]

Hi Chris. They may drop VIN numbers from easy access (they are still in the computer system) and THEY DO NOT NEED VIN NUMBERS to look up parts! THAT IS A FACT. I've done this many times this year for my 87 model, even over the phone. When I go in they look up the part for my year and model 6.9L and the screen shows all of the related parts to that part of the engine and how they are assembled along with the part numbers. They always print this out for me unless I tell them I don't need it. I usually deal with the parts manager who has been there for over 30 years but the other guys have done it too.

Not servicing vehicles after 10 years? HA! Drive a 20 year old truck to the Service Department, sign on the line for $1,000. plus repair and see how fast they come up with the parts and fix the truck!

Normally a part is not "obsoleted" until 20 years and some parts longer than that. I know this for a fact also. The VRV I want that controls the vacuum to the C6 is well over 20 years old (28 yrs) and has been on backorder by Ford Motor Company all of this year while they have been negotiating with a supplier to make more. If/When the negotiations fail (which is likely due to low demand, so little incentive for the maker to set up again to make the part) THEN the part will be obsoleted by Ford.

The good news is, you can fix the one you have or find an alternate.

The dealers I deal with. Moss in Sanbernardino and Sunland in Victorville wont even talk if you dont have a vin. Both told me 10yrs or newer only.