Said It Here

Temporary fix for a snapped coolant expansion tank nipple

Plastic coolant tank nipples often become brittle and snap off due to heating and cooling cycles, leaving no stub to connect the bleed hose to. While waiting for a replacement tank to arrive, temporary fixes like epoxy often fail to adhere to the pressurized plastic, leaving drivers stuck without a reliable way to drive their car.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Trying to use adhesives like JB Weld MarineWeld
  2. 2
    Drilling into the remainder of the nipple and securing a small tube or barbed fitting with adhesive
  3. 3
    Using a barbed brass nipple threaded into the hole
  4. 4
    using fuel tank putty
  5. 5
    applying epoxy repair
  6. 6
    replacing the entire tank
  7. 7
    sourcing a replacement valve from the manufacturer

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/autorepair1 person · September 2026

I assume through the many heating and cooling cycles the plastic nipple on my 2019 ZB Commodore's (I think it's called a Buick Regal in the US? and an Opel Insignia in Europe) coolant expansion tank has become brittle and snapped off.source ↗

It's the small coolant bleed hose connection right beside the expansion tank cap. I've managed to get the broken nipple out of the hose, but there's basically nothing left on the tank to connect it to.source ↗

Tried JB Weld MarineWeld, but it didn't adhere very well and just peeled straight off...source ↗

I've got a brand new one on the way for 50 bucks, but it's about two weeks away and I need the car for work.source ↗

rmxg · r/autorepair · 1 upvotes
r/AskMechanics1 person · September 2026

It's cracked where the black connector meets the purple tube so what's the best way to fix this? Can I replace this fitting or do I need to some sort of epoxy repair?source ↗

BlaZeD_87 · r/AskMechanics

Where this came up

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