How To: Repair Cracked Washer Fluid Bottle

[Mark D]

This issue came up in a different thread so rather than derail the conversation over there I figured I'd start fresh. There is a pretty simple fix to what seems to be a common problem: cracked windshield washer fluid bottles. To complicate the issue replacement bottles are no longer available from DMCH.

Long story short, when I bought my car I knew it had a cracked washer bottle and the previous owner tried without any luck to fix the crack using glue. The washer bottle material is high density polyethylene (HDPE) which is a tough material to get glue to stick to. Luckily it can easily be repaired by melt welding instead.

Step 1. To fix a cracked/leaking washer bottle the first thing you need to do is get the bottle out of the car by removing the black plastic bucket that holds it in place at the DS front trunk area. This can be a little tricky since there are eight M5 bolts holding the damn thing in there and like all of the other threaded inserts in the front you're bound to have a couple that have the bolts rusted in solid.
http://dmctalk.org/attachment.php?attachmentid=13405&d=1348117175


Step 2: Assuming you were able to get the black retaining bucket removed, do yourself a favor and drill a few holes in the bottom to let water and other debris escape. Mine was full dirt that had collected over the years... Trapped water (and leaking washer fluid) also collected and seeped into the pump at the base of the washer bottle causing the electric motor to fail. Note that in these pictures I've got the bucket completely removed, but you can just let it hang by the electrical harness that is routed through the large round opening in the top lip of the bucket.
http://dmctalk.org/attachment.php?attachmentid=13406&d=1348117177

Step 3. Next clean up any dried washer fluid residue and glue from previous repair attempts by you or previous owners. Make sure the the washer bottle is super clean around the cracked area to ensure a good repair.
http://dmctalk.org/attachment.php?attachmentid=13398&d=1348117163
http://dmctalk.org/attachment.php?attachmentid=13400&d=1348117166
http://dmctalk.org/attachment.php?attachmentid=13399&d=1348117165

Step 4. Find yourself an old milk jug made of HDPE. It's the translucent/clear plastic, not the opaque white plastic. Cut out a section of milk jug material slightly larger than the cracked area on your washer bottle and clean both sides of the patch section well. One nice thing is that milk jugs have all kinds of curves and contoured areas that you can find to match the shape of the washer bottle. The piece I cut was near the jug handle and fit perfectly in the little corner recess of the washer bottle.
http://dmctalk.org/attachment.php?attachmentid=13401&d=1348117168
http://dmctalk.org/attachment.php?attachmentid=13402&d=1348117169

Step 5. Using a heat gun warm up the washer bottle around the cracked area until it starts to get soft. Don't get it too hot or the plastic will blow out around the crack and you'll have a nice big hole instead of a hairline crack.
http://dmctalk.org/attachment.php?attachmentid=13404&d=1348117172

Step 6. Once the bottle is warmed up a little bit place your patch section of milk jug over the crack and heat it up until it's nice and melty. The thinner milk jug material will soften quicker than the thick plasic bottle so be careful. You can press down slightly on the patch to help create the bond between the two pieces of plastic.
http://dmctalk.org/attachment.php?attachmentid=13403&d=1348117170
http://dmctalk.org/attachment.php?attachmentid=13407&d=1348119540

Step 7. Check for leaks and reheat if needed to get a complete seal.

Step 8. Reassemble the bottle and retaining bucket back on the car being careful not to crush the harness or plastic tubing to the bottle as you tighten everything down.

Step 9. Drink beer in celebration.

[Spittybug]

When I pull mine out, I sincerely hope to find an equally easy crack to fix. I'm hoping it isn't along a long seam or at one of the nipple areas......

[SS Spoiler]

Good write up, nice pictures.

Paul Cerny

[Dangermouse]

Is the original bottle material thick enough that you could just re-seal the crack by using a putty knife to "melt" the two edges together when the bottle is warm enough?

[Mark D]

I don't recall the exact thickness of the bottle in that area but I'd guess somewhere between 1/16" to 3/32". The thickness varies in different spots bottle because I think they were blow molded.

You could probably get away with heating up the bottle in the cracked area and using some type of flat edge to fuse it back together. Or a hot soldering iron tip might do the job once you heat everything up and start to work the edge closed. I figured another layer of solid material over the crack was a good insurance policy that I wouldn't be going back in there again a few months later to make another repair. It wasn't much additional work to add the patch and it gave it some additional strength vs the original part in that weak corner area.

However, I'm pretty sure that my bottle cracked because the PO had to go in there and change out the original washer pump. When he reinstalled everything the bottle was not seated correctly and compressed and flexed in that corner as the bolts were tightened. If you are careful reinstalling everything there should be no compressive load on the bottle and there should be no reason for it to suddenly crack.

[Spittybug]

No luck. My crack is on the other side of the bottle, right in one of the compound corners....very challenging. I tried the milk jug trick and the bond just wasn't all that good despite a good cleaning and softening of both plastics. I tried a few times. I also tried simple melting/blending with a hot screwdriver. Still it leaks. The more I try, the more I'm stressing the surrounding plastic too. This isn't surprising after 31 years or so; despite popular perception plastic does indeed degrade and start to breakdown. I think we'll be seeing more and more of this.

Rather than patching the outside and fighting hydraulic pressure, I'm thinking I could line the interior of the bottle to seal the leak and help prevent others. I either need to be able to inflate something like a balloon inside, or more likely, pour in some kind of liquid polymer and form an interior skin. But what?

Other than that, has anyone found any other bottles that fit the space? How about an IV bag type of setup (flexible)?

[Dangermouse]

I almost hate to suggest it but what about that "as seen on TV" black Flex Seal stuff. If it actually works then you could coat the outside of the bottle.

Why not test it out on a plastic milk carton that you cut an slit opening with a knife to simulate a crack. Spray the stuff on, follow the instructions and see if it still leaks in 6 months?

[Spittybug]

Interesting idea...

Just tried again with more patching, more melting...nope. The original plastic has lost a lot of its elasticity and is more brittle. Consequently it doesn't really melt back to itself very well and the patch never really integrates to it. Just kind of sits on top and can't stop seepage.

[Bitsyncmaster]

There is a gas tank sealer used for fiberglass gas tanks that may work. You just pour it in and slosh it around and let it dry. That was used on a lot of experimental (home built) airplanes.

[Citizen]

Rather than patching the outside and fighting hydraulic pressure, I'm thinking I could line the interior of the bottle to seal the leak and help prevent others. I either need to be able to inflate something like a balloon inside, or more likely, pour in some kind of liquid polymer and form an interior skin. But what?



How about fiberglass resin? Make sure the crack area is at the bottom, so that gravity causes it to fill the crack....

I dunno, just the first idea that popped into my head.

Or maybe POR-15?

Thomas

...

[Spittybug]

I tried using up the last bit of POR15 I had in an open can. I TSP'd and marine cleaned first, but with that odd shape all I could really do was swish it around. I poured a little paint in and oriented the bottle so that it would collect at the crack. This morning I filled it up with water and no drips! However, the paint immediately un-stuck from the walls of the container and I pulled it out in a sheet. Tested again and it still doesn't leak, so I'm thinking that enough got into the crack via capillary action and has done the job.

It's not like it's a mission critical fluid and if it leaks again I'm no worse off than I was yesterday, so I'm going to re install and keep my fingers crossed.

[DMCMW Dave]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

[Dangermouse]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

But the guy on TV said that Flex Seal will stick to anything, or my money back :devil:

I wouldn't have believed it more if Billy Mays had said it himself.

But wait, there's more:

Actually thinking about it, the flex-seal wouldn't have to stick to the bottle for very long. As long as you completely covered the bottle, you would be creating an impervious outer skin. Any water that got into the gap between the bottle and the Flex Seal (assuming that it didn't stick) would drain back into the bottle when the water level dropped below the level of the crack.

[Mark D]

If laying a patch over the top isn't sealing well enough there are a couple alternatives you could try...

-Use sand paper to rough up and form a slight V groove along the ridge of the crack. You can also use dremel or a very sharp exacto knife if you are careful.
-Cut very thin narrow strips of plastic to use as a "welding rod."
-Use your soldering iron to melt to heat up the bottle along the V groove while slowly feeding in your filler material.

OR

Lay a patch over the top of the crack as I described in the first post. (no need to get a complete seal using the heat gun)
Use your soldering iron to flatten out the edges of the patch and melt them into the surrounding plastic. As long as you seal the edges of the patch the crack below does not need to be completely sealed.



It took me a few tries to get my repair to seal completely...didn't use a soldering iron but remember having to press down in a few spots with a blunt object while using the heat gun to work the two layers of material together. This was back in 2009 and it's been holding strong since then.

Oh, and another trick. If your bottle starts to sag inward from the repeated heating attemps just blow into the bottle (gently!) to push it back out until it cools off again. It's also a good way to allow you to push a little harder as you try and press the patch material down into the bottle.

[Spittybug]

It is difficult-to-impossible to get something that adheres well to polypropylene plastic (What the bottle is made of). You need to "melt" the repair together.

Dave, I could have sworn that it was HDPE....PP is usually softer. But if indeed it is PP, that would certainly explain the difficulty in getting a HDPE patch to really adhere! PP and PE don't usually play well together once extruded and formed.....

[Spittybug]

Damn it! Put it back in the car since it looked like the combination of the POR15 in the crack and the plastic welding was holding. NOT.

Now in the market for a WW fluid tank.

[Mark D]

Damn, sorry to hear you're still strugging with the leak issue. There's gotta be a way to melt that thing back together. If the material is PP and not HDPE then dig through your recycling bin to find something with a #5 recycling code on it instead of using the milk jug plastic. (HDPE is #2)

[Dangermouse]

Now in the market for a WW fluid tank.

World of Warcraft? World War? Wascally Wabbit?

[DMCMW Dave]

Damn, sorry to hear you're still strugging with the leak issue. There's gotta be a way to melt that thing back together. If the material is PP and not HDPE then dig through your recycling bin to find something with a #5 recycling code on it instead of using the milk jug plastic. (HDPE is #2)

I could be wrong, but it is some sort of plastic that always feels greasy. I just assumed PP.

[stevedmc]

You could just sand it and then wrap it like crazy with fiberglass.

[Mark D]

Now it's bugging me to know what kind of plastic the bottle is made out of. I searched and found this simple chemistry class experiment.

http://journeytoforever.org/biofuel_library/plasticsidentification.pdf

Apparently PP is less dense than HDPE and will float on vegetable oil, but HDPE will sink.

If someone wants to cut a small chunk of plastic off of their tank and see if it floats in oil that would be one way to confirm what it's made of.

[stevedmc]

Bill Robertson has two windshield washer tanks in good condition he is not using. Unfortunately Bill has been permabanned from this forum so no one can send him a PM about buying them.

[Dangermouse]

Somewhat related to my As-Seen on TV suggestion, I came across this on another forum: PlastiDip

http://www.homedepot.com/catalog/productImages/300/f5/f58bedb4-ae5a-44e3-9f64-2403bddcf545_300.jpg

http://www.plastidip.com/home_solutions/Plasti_Dip

Brush or spray on plastic coating: $6 a can at Home Depot. Maybe worth a try

[Spittybug]

I may give that one last try.... I'm just not sure that any exterior coating is going to work. Ultimately hydraulic pressure wins (look at the Grand Canyon).

[stevedmc]

Whats wrong with wrapping it in fiberglass? Surely layers of fiberglass would hold much better than some silly little as seen on TV product. Fiberglass kits are only $10 at Walmart.

[Dangermouse]

The first one was As-Seen-On-TV. The second is As-Seen-On-The-Internet which is obviously much better.

I think to be successful, the whole bottle would have to be coated. Just patching wouldn't work. It may just end up being an outer balloon.

If it is unsuccessful, the stuff just peels right off.

[stevedmc]

Too bad Bill has been permabanned. It definitely would be a lot easier and probably would be a lot cheaper just to buy one of his surplus bottles.

[Spittybug]

Steven Rice, it is not "too bad" that Bill Robertson has been banned for life. While I have had no problems with Bill in the limited one-on-one communications I have had with him, and in fact he has been quite helpful, it was his actions/attitude/behavior/demeanor/idiocy/belligerence on this board that ultimately resulted in his ban. Such is life. Move on. He does not need you keeping his "memory" alive at every opportunity.

I appreciate your bringing to my attention the fact that he has bottles and if I desire to make him an offer for such, I will. There are others with bottles that have privately offered to sell them. Rest assured I'm not losing sleep. Sometimes solving the problem is more fun than simply eliminating it.

Your martyrdom in the name of Bill Robertson is a mighty small ambition in life. I challenge you to give it up and become your own person.

Thanks for your concern.

[stevedmc]

I challenge you to give it up and become your own person.

It would be foolish to say that traveling to 27 countries, 6 continents, and 49 states has not made me my own person. I've tried to get others to visit North Korea with me, but for some reason people don’t want to go there.

If it were my bottle I would just wrap it in fiberglass.

About 6 months ago my Geo Metro fuel tank had a leak. I spent $10 on a fiberglass kit, sanded the tank, wrapped it, and problem was solved.

Personally, I wouldn’t bother buying one of Bill's washer fluid tanks when you can fix your existing tank for $10.

[Mark D]

I was at the auto parts store yesterday and came across a kit from Permatex for repairing plastic washer bottles. It comes with a small section of fiberglass material and some black goopy resin that apparently is designed to bond to the washer bottle plastic.

Website here:
http://www.permatexrepair.com/product/plastic

Instructions here:
http://www.permatexrepair.com/docs/PlasticTank.pdf

Can purchase at any auto zone, advance auto, napa, O'Reilly, etc for under 10 bucks. It might be worth a shot to try if all other options have failed.