Repair Cracked Plastic Radiator

If your car radiator has a small leak, you may be wondering if it is possible to repair a plastic radiator and fix a radiator leak. Afterall, there is high-pressure, high-temperature coolant in the radiator tank. You may ask yourself, "How can a radiator epoxy adhesive possibly hold up under those conditions?" The answer is that it probably can't. It may fix the radiator leak temporarily, but over time, the radiator adhesive will, more than likely, come off.
If you take your car to a radiator repair shop to repair a leaking radiator, you will often find that they will repair metal radiator tanks but NOT repair plastic radiator tanks. Instead, the radiator repair shop will probably try to sell you a replacement radiator. The replacement radiator cost can be very high compared to just repairing something so minor and easily repairable.
Radiator tank repairs are not difficult at all. Just keep in mind a few things when you are repairing a cracked plastic radiator tank. First, the repair has to withstand high operating temperatures (200°F or 94°C and up).
Second, the repair has to contain hot, pressurized coolant, making it immediately obvious when your weld is less-than-perfect. Because of the harsh operating conditions, the radiator tanks are made from glass-reinforced nylon, a plastic that features a high-softening point. The high-softening-point nylon plastic is what helps the plastic radiator tank withstand the pressure and temperatures involved.
Adhesives don't stand a chance in such an environment. There's no way an adhesive bond can hold on over the long run at such temperatures with high-pressure water behind it.
The only true way to patch a plastic radiator tank is with a true fusion weld. The Radiator Repair Kit enables you to melt pure nylon fill material directly into the base material, creating a seamless, strong repair.
Creating a durable weld repair is not as easy on the radiator as it is on other plastic parts because of the high melting point of the nylon and the harsh operating conditions. However, by following the simple step-by-step procedure we have outlined here, you will be making quality repairs in no time.
Featured product:
- 5212 Plastic Radiator Tank Repair Kit: www.polyvance.com/Radiator-Re...
View this video on our website for more information:
www.polyvance.com/video/radia...
Chapters:
Intro: 0:00
Radiator repair kit: 0:10
V-groove: 0:45
Using a heat gun (optional): 1:06
Welding the nylon rod: 1:29
Checking the weld after starting the engine: 2:30
⚠️ Important ⚠️
- Always wear proper safety gear while working!
- The length of this video is in no way representative of the actual time required to perform a complete repair and therefore should not be used for estimating purposes.
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[@tattoosteveneo]

Old video but I have this welder. Fixed a poly gas tank for my old truck. That was around 10 years ago. Still not leaking. This thing has saved me more money than I know. It’s worth every penny you pay and then some.

[@polyvance]

Awesome! Thanks for sharing your story with us!

[@yoshinishimura5574]

Thanks for your answer, Scott.

[@djohnnineonesix820]

Excellent video. Since I'm planning to keep my cars for a long time. I replaced the plastic radiators for full aluminum and more capacity radiators... Northern California gets super hot sometimes...

[@scottb7600]

Yes, we have a race car and did the same. There are times when more cooling capacity is needed.

[@charleski4032]

That first part had my teeth clench. Its like watching the radiators funeral. Any more sec. I would' ve been in tears.

[@carlosbonapartelenox9168]

This a good video. Thank you from Guatemala...it goin too help a lot to many peoples in that cars problem.

[@polyvance]

Thanks for watching!

[@Kotaztrafee]

Excellent. I have been trying to find out what type of plastic. NYLON. Thanks a lot.

[@Maicon-b1b]

Same

[@eliascastello4756]

Nice dude that's a appropriate repair

[@markquigley7839]

I was doing the same thing in the 70's when I worked in a warehouse repairing plastic totes.

[@19211265]

Good job Love the metal rock theme 🤘🏻

[@polyvance]

Thank you so much!

[@raitshots]

Esay rebuild every car model radiator soldering aluminion and pvc 😎👍 Good video

[@user-kr8zb7js2r]

Simple but very usefull

[@polyvance]

Thank you for watching!

[@Eduardo_Espinoza]

So when do you recommend to use the ss mesh?

[@Radputnamdisc-lx7jk]

Kicking ass video

[@user-jn6bk3ug7k]

Good job عمل جيد

[@polyvance]

Thanks for watching!

[@IngeniousOutdoors]

Just use a soldering iron and zip ties (they're made from nylon plastic) as welder rods. Works the same.

[@scottb7600]

Its difficult to get a pinhole free weld using that technique. Most soldering irons have too small of a tip to provide adequate pressure to the substrate to get a good weld. Also many zip ties contain a nylon blend which may not be a great match for the type of nylon radiators are made from. I have also run across zip ties made of polypropylene and HDPE, which will not weld with nylon at all.

[@AmericanThunder]

@@scottb7600 Most soldering irons come with a flat tip attachment specifically for that purpose.

[@scottb7600]

@@AmericanThunder Most are still not typically large enough unless you have a REALLY BIG soldering iron and you have the ability to control the temperature of the iron.

[@AmericanThunder]

@@scottb7600 I've been doing decent plastic welding for about 40 years using a Weller iron with a flat tip, no issues, it just takes practice.

[@scottb7600]

@@AmericanThunder I'm not saying it can't be done. Its just much easier with the right tool. The airless welder has its origins in a soldering iron. The custom tips were added to make the process much easier and faster than using the smaller tip of a soldering iron. The output of the tool was then adjusted to best suit plastic repair, followed by a temperature controlled version for even more control on low melt-point materials.

[@johno9507]

A soldering iron and scrap plastic from a old radiator works just as well!

[@hellcatredeye-g6582]

Actually pretty impressed

[@polyvance]

Thanks!

[@steveY2K1]

Tried welding plastic using your kit from Polyvance, guess the radiator was too old, because after two tries, still leaks after running for 15 minutes...disappointed that it failed to work for me...

[@hassanjassoma5809]

Very good

[@polyvance]

Thanks for watching!

[@allanbrogdon7453]

Stop drilling the end of the cracks helps in aluminum but melting the plastic should take care of it .When radiators weren't plastic I repaired a hole in a car battery with a prestone bottle and a hot glue gun.

[@dennisgrant4266]

My radiator filler neck broke off. I stuffed an old glove in it 'til new radiator came. $55. on eBay. Free shipping.

[@ryanolsenhhs]

What if you didn't use a chisel to put a crack in it? I only have a small thin crack but it is enough for fluid to bubble out, what's the best bond with heat resistance that can be used quicker than this approach?

[@scottb7600]

A crack is a crack, no matter how small...plastic welding is the only permanent way to repair it.

[@markman63]

Does this work with PA66-GF33 (motorcycle oil tank)?

[@btwbrand]

PA66 is the code for Nylon... GF33 indicates it is 33% glass filling powder and strands for strength. PA66-GF33 is 33% glass filled Nylon. You can repair this mixture of nylon with more nylon. This is what this entire video is showing. Yes it works on a motorcycle oil tank. I need a drink.

[@kimstuart7989]

does the nylon rod come with the plastic welding kit and if not, where can you buy the nylon rod?

[@polyvance]

"Yes". The nylon rod comes with the kit.

[@kimstuart7989]

Polyvance thank you so much!

[@garyaubrey4096]

That kit costs as much as a cheap radiator. If it were half that price I would buy one, but for a little more I could buy a good radiator. Not worth it unless you are a shop that repairs them.

[@duracontractors]

@@garyaubrey4096 a replacement radiator is about $150. Plus, here with the repair, you don't have to remove and reinstall. Savings$$$$$

[@Eduardo_Espinoza]

@Gary Aubrey yes, I'm thinking of using a $20 3d pen & a wood engraving tool

[@AngelMartinez-zj9hc]

Do u have the radiator support of a sunfire 2004 is the one with the little hole

[@polyvance]

Angel, Unfortunately, we don't sell radiator supports, we just manufacture plastic repair products.

[@yoshinishimura5574]

My '98 Chevy Tahoe has a pinhole on the plastic part of the radiator. Can I use soldering iron instead of buying a whole kit to melt the nylon rod? Just asking. It'll save me a bunch of money. Thanks.

[@scottb7600]

I'll say this, you can always try. The big problem with a soldering iron is temperature and surface area. The welder makes the weld much easier...plus if you have any broken plastic in the future, all you need to get is the right filler rod and you're good to go!

[@zeus-io3hn]

how long did it last? i am interested in this product.

[@polyvance]

This video was done circa 2009 and that car is still on the road, going strong with no issues from the radiator at all since the repair.

[@polyvance]

Or this video was filmed in 2009, I should say.

[@zeus-io3hn]

thx, for helping me clear my mind over epoxy and plastic welding.

[@polyvance]

That's what we're here for!

[@KSMike1]

Are ALL plastic radiator tanks nylon? I just discovered a pinhole in my 98 F150 (built in 97). I’ve already got this tool with nylon rod.

[@DStezzy1]

Where can one purchase this product?

[@polyvance]

The plastic radiator repair kit can be purchased on our website, which is linked below. Thank you for watching! www.polyvance.com/New-Products/5212/

[@Fluery]

Cool kit but... I have a lot tools but not a heat gun, not a laser thermometer, not a plastic welder melter thing. This is way to specific in tools which your average person WILL NOT HAVE!

[@polyvance]

The laser thermometer was to demonstrate how much we heated the radiator. It isn't necessary. The heat gun is also not necessary, but it speeds up the process (as stated in the video). You can buy both the heat gun and the plastic welder kit from Polyvance. The links to both of these items are in the description box.

[@noahfury9530]

Fluery

[@kracin]

Ive got them.... maybe spend 30 bucks also?

[@orlando9609]

Acquiring the basic tools which in this case is just the soldering one and the plastic or nylon to be melted, it's way cheaper and easier than replacing the whole radiator, talking about an average person

[@nigelssurfshop]

and if you buy all that you will use it once, and you could have paid for a new radiator instead

[@Lynxzit]

Good video.. what about repair a broken plastic pipe on the radiator. For ex the very smallest connection that goes with a hose too the expansioncooler container

[@scottb7600]

It can be used for that as well. Be sure to use some of the mesh in the kit to reinforce the repair after you weld it to add tensile strength.

[@Lynxzit]

@@scottb7600 Great. When i was writing this i looked into the same channel that they did just that in an other video too fix a longer thinner pipe on the radiator hehe

[@polyvance]

Do you want to know how much Polyvance believes in their products? The radiator featured in this video was in a vehicle that belonged to Polyvance's Vice President. We drilled into his perfectly good radiator because we know our products work, and we knew we would be able to repair it. This repair was done around 7-8 years ago. This vehicle has since changed hands (but stayed in the Vice President's family.) The vehicle is still driven often. The repair on this radiator has held up all this time.

[@jjjsmith2497]

Polyvance. Not to rain on your parade, But when in a normal plastic radiator failure situation, (not a pre-planned one) if one part has cracked the other pieces should not be far behind.

[@aaronsalvesen4553]

Where can i find this music!?🙌🤘

[@alekkella5589]

Can I use torch lighter? Instead of heat gun?

[@scottb7600]

No, the plastic will overheat, oxidize and become brittle.

[@jaye5925]

Where and how can i buy more of the nylon rods? I don't want to keep buying the kits just for the rods.

[@polyvance]

Hi there! You can view our nylon welding rods on our website: www.polyvance.com/Nylon-1/

[@jaye5925]

Polyvance thanks a lot

[@polyvance]

You're welcome!

[@nkaujhmoobleegchannel3734]

Hi I have a question ? How do I know if the radiator is broken ? Also if my car isn’t over heated can I still drive it with a crack radiator?

[@venomx4093]

If the radiator is cracked, you will see it leak. If it's leaking, it will overheat once the coolant leaks out. If you continue driving it while overheating, you can warp the heads.

[@oldgamer1330]

Are you for real or is this just a joke.

[@andymckinney8958]

What if the crack is along the crimped metal housing?

[@polyvance]

A crack along the metal is a little more tricky. We only focus on the plastic elements, as they seem to be the most common repairs to happen upon.

[@andymckinney8958]

I thought that may be the case. Thank's for the response.

[@polyvance]

Of course! Thank you for watching!

[@AngelMartinez-zj9hc]

Polyvance what kinda car is this

[@souocara38able]

That looks a lot like the '95 Thunderbird I worked on today. My crack is by the tab that holds the nut clip for the fan shroud :-(

[@mikep95133]

How did you find out that the tanks are made from glass filled nylon?

[@polyvance]

The symbol molded into the tank was PA+GF20 which means PolyAmide (Nylon) + Glass Filled 20%

[@georgiacat7958]

@@polyvance daaaaaaang

[@johnharrison2466]

If it's a small hole or crack drill it out and put a expanding rubber freeze plug in tighten and your done no chance of the polycarbonate separating again fixed radiators like this for years !!!!!!

[@elrayjones5496]

The kit is 80 bucks. My new radiator was 88 bucks at A1 auto .com. Probably a good tool for repairing something but not radiators not cost effective.

[@scottb7600]

Yeah, some radiators are really inexpensive. However, if you have a kayak, atv or other plastic things that tend to break, they can also be welded with the same welder. Keep in mind you would use a different welding rod for each type of plastic, but the welder itself can be used for a lot of things.

[@alriston]

Ta de sacanagem 1 hora p chegar a 68°c no Brasil o motor ja liga nesta temperatura kkkkk e remendo sairia voando em 10 minutos

[@perfectoj7775]

What if you don’t have a plastic welder?

[@LVPHD1]

I just used JB weld. $6.00, one day to let it set and voila! No more leak.

[@LVPHD1]

And my repair looks a lot more esthetic than that lol.

[@Swingfree1947]

@@LVPHD1 I tried several adhesives on a crack in the side tank of a Mk1 Ford Focus radiator without success. That included a product made especially for radiator repairs and a couple of other epoxy products. We've had the radiator out 3 times now, but it has failed very quickly every time. I am wondering whether to try welding, but some say it doesn't work.

[@j.onofre6613]

There's no thermostat. Temp too low, is not soupost to be over 200? I use jbweld and works fine... even on metal.

[@namdzang619]

I am told about JBWeld but there are different types and how do you apply it please

[@j.onofre6613]

Nam Dzang jbweld the red one. Just sandpaper, clean and dry the area, and apply a coat of jbweld let it dry, but depends on ambient temp. I always put 3 caps of jb. Never have a leak again in that area..

[@terrybowman604]

@@j.onofre6613 I tried the regular JB Weld and it stuck well, but still cracked in the same spot. Does the "RED" flex, if so that should fix my issue.

[@btwbrand]

Temp should be low on the side he is working on.. the hot coolant enters on the other side and cools as it reaches the location he is working on.

[@q-bert6454]

You must play the same music while doing this repair. That’s the first step

[@polyvance]

It couldn't hurt!

[@aaronsalvesen4553]

Who is this playing!? It Rocks!

[@MultiBeast301]

Yo who does the music?

[@andrewmanzi2969]

Would a product that is called JB Weld work?

[@polyvance]

JB Weld will not be a permanent fix. The bond will not withstand the repeated expansion and contraction of a radiator.

[@timekeeper46]

I have welded plastic with a soldering gun and a piece of scrap plastic.

[@polyvance]

It's more or less the same principle. The main difference is the welding rod, which will be cleaner and identifiable as a specific type of plastic so you can match it exactly.

[@got5at12]

BIKE PATCH WORKS.

[@Spacegoat92]

How would this go on an older radiator where the plastic has fatigued?

[@scottb7600]

Seems to work well, in my experience.

[@btwbrand]

The thing that destroys Nylon radiators is Heat ( and hammers, drills, chisels). Overheated engines weaken the plastic as they are designed for normal hot coolant temps. Higher temperatures from an overheating engine will turn the nylon brown or tan and brittle over time.

[@carolynwilliams2722]

What if it have a bigger hole how can I repair it cheap

[@polyvance]

You should still be able to use this product. Check out this video where we repair two large cracks on a radiator: kzbin.info/www/bejne/hWeai56Bh9OCjK8&t

[@skate04ever1]

I just had my plastic radiator crack after an overheat. it seems that the coolant inside boiled and because of the too much pressure, it cracked its way open. it has a quite long crack about 4 inches. do you think it can still be repaired with this method? thanks

[@scottb7600]

Yes, you can weld it as long as the crack doesn't extend into the fins. A lot of times that failure happens as the result of your head gasket blowing which pressurizes the coolant system to the point where the weakest link fails...which in turn would make your car overheat because it blew out all your coolant.

[@Eduardo_Espinoza]

I would check the safety valve before fixing it

[@thomashorvath7026]

What if the crack is in a part where you can't do that work to fix it

[@btwbrand]

Another radiator is always an option.

[@YDVDL]

incredible tool..but if you do a one time job - ask yourself is it worth of spending all that money or easier to get new radiator with warranty...i guess new with warranty and moneywise you break even,except the fact that you still driving with old patched radiator if you buy this tool... STILL THUMBS UP TO INVENTORS,because if you have garage shop this tool is MONEY MAKER!!!!!!!!!

[@scottb7600]

even a home shop it will save you money. You can use it on other plastics as well, you just change which welding rod you use to match the substrate.

[@Eduardo_Espinoza]

That bad Amazon review was actually done wrong, I see (white scab one).

[@polyvance]

Visit this video page on our website to see the full list of products used and other helpful tips: www.polyvance.com/video/radiator-repair/repair-cracked-plastic-radiator

[@buckaroosol]

Can you use any type of nylon like say a nylon washer? And how long do you have to wait for the nylon to solidify?

[@scottb7600]

It may be possible, but there are hundreds of varieties of nylon and each has specific properties and are chosen for specific applications. Not every nylon likes to be blended with every other nylon. That said, if you tried it and it didn't work, you could always start over, grind out what you put in and weld it with the R06-01-03-NT welding rod.

[@buckaroosol]

Scott Bixler yeah, i wish I seen your reply because I already had a plastic welder and some nylon washers and it just stressed fractured right after starting the car. I couldn’t find that much info on nylon so your reply helps a lot thanks man.

[@scottb7600]

You're welcome!

[@Eduardo_Espinoza]

Heard you can break a piece off the rad. As filament

[@josedomingomoraismujica9114]

❤❤❤

[@axa.axa.]

great for that pesky drill hole or chisel crack.... too bad most cracks are at a right angle inlet or outlet, way harder repair

[@polyvance]

You might enjoy these other radiator repair videos instead: kzbin.info/www/bejne/r6iqhGyQgceMbbs kzbin.info/www/bejne/hWeai56Bh9OCjK8

[@raidel25]

Just use JB weld , it's way easier and cheaper.

[@polyvance]

JB Weld will not be a permanent fix. The bond will not withstand the repeated expansion and contraction of a radiator.

[@scottb7600]

Yeah, and totally temporary and unreliable.

[@Swingfree1947]

I tried to use a JB Weld radiator repair kit but it set before I could apply it. I later used a very similar product by another manufacturer but it failed immediately.

[@georgiacat7958]

@@Swingfree1947 jb weld could work IF and only IF you can seal the leak from inside which is pretty much impossible. Anything added on the outside will never ever hold, we are dealing with an uncompressable liquid which expands when heated, this creates tons of pressure (not literally tons) and the repair won't last

[@irfan1373]

Just thread a little over sized screw and you are good to go.

[@dkt1976dt]

The only problem is make sure the screw doesnt get too hot or it will melt the plastic

[@steveec9704]

I used flex seal lol

[@chrisshears9257]

Did it work

[@scottdamitt]

that music!? yeah! \m/(-00-)\m/

[@AtTheHandle]

Ain’t worried about a hole we’re worried about bad cracks at joints

[@scottb7600]

You can repair those too. The kit comes with some stainless steel mesh that can be used to reinforce those seems even more.

[@WibbyKDX]

Kit costs more than a new radiator

[@dwreckbaker6382]

Nice try Einsteins, but those style radiators crack and or become not sealed at the crimping points, have never seen that style crack as you show in the 47 years Ive been around vehicles...... BLUE DEVIL works well in heater cores, radiators as well as head gaskets....for a while & not permanently

[@scottb7600]

Polyvance did not create a product to solve a problem that supposedly does not exist. Radiators crack all the time at places other than the crimp seal. Filler neck cracks are EXTREMELY common.

[@Jonathan81284]

Why do you think I'm on here right now that's around the same place my crack is

[@rahrah8076]

Same place where mine is cracked

[@raitshots]

Nja remember+ 90 standart function radiator cooling system. But problem again +100 temperature. Radiator kaput

[@hnajee]

For plastic radiator leak, forget everything. Use Weicon Aqua repair stick. Made for plastic radiators. Used it n satisfied. Takes upto 120 C (250 F). The extra I have I will use for my plumbing

[@scottb7600]

That is not a permanent repair.

[@DanLoFat]

of course I see no leak at 800 RPM Tri 2500 rpm for about 5 minutes see what happens.

[@polyvance]

We've used this for repairs on radiators 5-7 years ago that still function flawlessly.

[@Bakebreal]

Can’t you use epoxy or Gorilla glue too?

[@scottb7600]

those do not bond well to nylon, nor do they handle expansion and contraction well so they fail after a short period of time.

[@ricksalisbury4219]

Ok,smart men,.crack on the side that is full of corrosion. Any suggestions besides a new radiator?

[@scottb7600]

If its the aluminum part, you are SOL, but if its the plastic part, you'll need to use a dremel tool or a di grinder to grind out the corroded area. If its a big hole, you'll want to cut a piece of 2045W stainless mesh about 1/2 in bigger than the hole all the way around and melt the edges in. This will give you a support structure with which to fill the hole. Once that's in, simply weld over the hole using R21 glass reinforced nylon welding rod, blending it well at the edges with the base material an forcing it into the mesh to get a structure that behaves as one piece.

[@capitalr8649]

Crazy glue should work the same!!

[@scottb7600]

only if you want it to pop off and leak at the most inconvenient time.

[@dkt1976dt]

Just buy a new radiator, you can get them for less than $100 online brand new.

[@scottb7600]

Depends on the car!

[@dkt1976dt]

@@scottb7600 I just bought a brand new radiator for $60 dollars for my 04 Jeep Liberty Renegade off of Amazon.

[@scottb7600]

@@dkt1976dt I'm not saying they aren't out there. but many are well over the $200 mark.

[@dkt1976dt]

@@scottb7600 The radiator for the 94 BMW 530i was well over $200 dollars

[@roberttwomey469]

shit works

[@RickPreciado]

really? i tried using shit but it didn't work. made a mess though

[@scottshake8440]

JB weld will fix it also

[@scottb7600]

Not permanently.

[@LeisureSuitGaming2]

Nobody has these tools are radiators aren't that expensive. They are 50 bucks on my car lol this is dumb.

[@mlmajortodaleague147]

..better off getting a raditor

[@brapamaldi7666]

if you can afford it, yeah. if not, then this is a very useful technique to know

[@sgt.gonzoblogs1730]

so if you’re not a mechanic good luck as you have none of those tools

[@btwbrand]

If you are not a dentist good luck working on teeth as you have no dentist tools.

[@optimusprimo2012]

Who does that?