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.

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View this video on our website for more information:

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.

[djohnnineonesix]

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...

[carlosbonapartelenox]

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

[charleski]

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

[Kotaztrafee]

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

[steveYK]

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...

[IngeniousOutdoors]

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

[markquigley]

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

[raitshots]

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

[johno]

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

[allanbrogdon]

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.

[Eduardo_Espinoza]

So when do you recommend to use the ss mesh?

[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?

[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]

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.

[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

[perfectoj]

What if you don’t have a plastic welder?

Good job
Love the metal rock theme 🤘🏻

[eliascastello]

Nice dude that's a appropriate repair

[dennisgrant]

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