My thermostat gasket is leaking on my 00 Ford ka. Is there I sealant I can put around it as a temporary fix for a week or two before I can get it fixed?


There is no way to put sealant around the outside of the housing to get it to stop leaking.

You could possibly put a sealant within the coolant system, such as Bar's Radiator Stop Leak, which may or may not solve your leak issue temporarily (may solve it permanently, but I never trust it).

Your better bet is to just replace the gasket. This is a relatively easy procedure which can be accomplished with basic hand tools. I found part 1 and part 2 videos on the procedure, which are pretty decently done. For a basic run down on how to do this, here are the basic steps:

  1. Drain your coolant system.
  2. Remove the two clamps from the hoses on the housing. Slide them down the hose away from the housing as an easy way to keep track of them.
  3. Remove the two hoses from the housing. Inspect the hoses for obvious damage or wear. Replace if you find cracks or deterioration on the inside of the hoses at the end.
  4. Remove the two bolts holding the housing. Clean these bolts thoroughly.
  5. Remove the housing.
  6. Remove the thermostat.
  7. Clean the housing and the head at the mating surface. This area needs to be clean and free of debris. Be careful not to lay deep scratches in either part as this will impair the sealing ability.
  8. Install a new thermostat (see note below). The spring portion of the thermostat should be pointing down.
  9. Install a new thermostat housing gasket. (Note: You can use some gasket sealant here to help in the sealing process, if desired.)
  10. Put some anti-seize onto the bolts, then install the bolts until they are just snug.
  11. Replace the two hoses.
  12. Replace the two hose clamps.
  13. Tighten the two bolts down about another 1/4 turn (I do not have a torque spec on these two bolts, but they do not need a large amount of torque to seal things back up). Do not over tighten these as you can crack the housing or strip the threads out of the head.
  14. Refill your coolant system with radiator fluid.
  15. Run the engine up to temperature looking for any signs of leakage. If you detect any leaks, shut the engine down right away, then find/fix the leak.'
  16. Fill the expansion tank with coolant as needed to keep it up between the min/max lines.

NOTE: Since you are installing a new gasket, now is the time to replace the thermostat as well. When you get the new thermostat, the gasket will come with it.

  • Is it necessary to drain ALL of the coolant? I'm not familiar with this model but most cars have the thermostat high up on the engine or radiator so draining SOME coolant is necessary but not all of it.
    – Freiheit
    Jan 25 '15 at 3:35
  • @Freiheit ... You are right in that assessment. You would only have to drain it down to the point where the level is below the level of the thermostat housing. These directions are meant to be a little on the generic. Jan 25 '15 at 13:16
  • 1
    however, it's probably worth changing the coolant at the same time, unless you know it's been done relatively recently...
    – Nick C
    Jan 26 '15 at 10:36
  • @NickC ... Ayup. Good point. Jan 26 '15 at 11:01
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    Hey I'm going to replace the coolant to I have removed the housing and gasket and thermostat but where do I put the new coolant mix? Into the hole where the thermostat was? Also will removing the bottom hose from the rad get rid of all the old coolant? Thanks Jan 26 '15 at 20:48

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