# No heat while radiator cap is on

**URL:** <https://community.cartalk.com/t/no-heat-while-radiator-cap-is-on/128625>\
**Category:** Maintenance/Repairs\
**Created:** [November 11, 2018, 3:19pm UTC](https://community.cartalk.com/t/no-heat-while-radiator-cap-is-on/128625 "2018-11-11T15:19:57Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [November 13, 2018, 7:42pm UTC](https://community.cartalk.com/t/no-heat-while-radiator-cap-is-on/128625/21 "2018-11-13T19:42:36Z")

</div>

The reason auto manufactures add stop leak to the cooling systems is, when you build millions of vehicles, and when millions of cooling system parts such as radiators/heater cores are supplied by suppliers/vendors, not every component is going to be perfect. So, the stop-leak is added to prevent any possible leaks.

When I saw a stop-leak being added to new Ford Rangers at the old St Paul plant, I asked the plant manager why.

He looked at me and said, **“We’re here to make trucks. Not repair them.”.**

Tester

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