Coolant Leaking from Radiator Cap?

[The Critic]

Did a water pump, serpentine belt, and coolant replacement on a '91 Plymouth Grand Voyager SE 3.3L V6 several weeks ago.

Today, I get a call saying that coolant leaks out of the radiator cap periodically when the engine is hot, and at a "stop."

The Radiator is approximately two years old, the cap was replaced shortly before the water pump job.

The car is NOT overheating at all. Temperature gauge is in the normal zone.

My guess is that the radiator cap is defective. Any ideas?

Thanks in advance.

 

[Dad2leia]

Before looking into a replacement radiator, check to see if the cap itself indeed may be defective. Even if the place you bought it at won't see it that way, it definitely is a less expensive fix than a radiator replacement.

If it still does it, then unfortunately it is the radiator.

 

[johnd]

This happened to me on a 3 year old car and the problem was fixed by a cap replacement. I pressure tested the cap and it was more like 8-9 lb instead of the required 13. Now that I always check them, I find most caps actually have lower real pressure than how they are marked.

 

[Chris142]

Does the cap have the red flip up lever? Those always leak.

Check the rad for damage where the cap fits. If it's ok replace it with a cap w/o the lever.

 

[Quest]

If your radiator is one of those plastic+alu fin type, check the plastic filler neck/rad cap mating surface for cracks or uneven mating surface.

Chris142-

as far as replacement rad cap's concerned, I'm sure nobody uses those caps with red levers to relieve pressure anymore (grin)

 

[The Critic]

Thanks a lot for the quick responses.

Yes, it is one of those flip-up types with a lever!

He just called me and says he thinks its leaking from the water pump ??? I have a feeling that he really isn't sure where its leaking from...and he lives 100 miles away from me.

Relatives...

 

[Tosh]

No good deed goes unpunished! That's the reason you shouldn't work on other people's cars...

 

[The Critic]

Yeah, I know now.

Anyway, problem solved. He took it to the shop, and they pressure tested it. Found out that one of the bypass hoses were leaking. Didn't touch those, not my problem.

 

[rriddle3]

Quote:

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Does the cap have the red flip up lever? Those always leak.

Check the rad for damage where the cap fits. If it's ok replace it with a cap w/o the lever.

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Maybe that's been your experience, but I've never had a problem with a Stant Lev-R-Vent cap, knock on wood. Just like any cap, they don't have an infinite lifespan, though.

 

[GMGuy]

Might be the overflow hose is loose. If its held on with a spring clamp, it just isn't springy enough any longer, ran across that more than once.

Alex.