Hi guys,

Back in January I noticed the coolant level was on MIN, there was also evidence of dried coolant marks around the expansion tank. I didn’t worry to much because I had to change the bleed screw on the radiator So decided to bleed the system again and made sure it was on MAX.

Yesterday I done a service on the car and noticed Coolant droplets on the side of the air filter box and on the top of the Coolant tank, Coolant just above min again,

I’ve searched the net and the forum but can’t find an answer.

Is there any common faults with the GP coolant bottles leaking? Either with the cap or the seams around the the bottles between MIN & MAX?

I got a feeling it’s the coolant tank/bottle seam because it never drops below MIN, just wondered if this was a common problem on the GP or anybody else has experienced this,

If you check the level when the engine is cold, it should be at or just above the MIN.
If you check the level when the engine is hot, it should be at or just below the MAX.

The difference is because when the engine is hot, the coolant lines are pressurized and the coolant is obviously hotter (= thermal expansion).

Guess we gotta remember these cars are getting on a bit now..rubber/seals do perish so it might be worth looking at the cap itself first..

The pressure cap on the coolant reservoir has failed on your car. It's very common maintenance item and it's very probable that it had never been changed before. Its failure can cause other leaks elsewhere in the system and also overheating due to the system not pressurizing.


Check for other leaks too, thermostat housing gasket might also leak a bit and also the waterpump pipe gasket. Especially if it needs a top up every now and then.

Thanks for the reply’s, I’ll get a new genuine Fiat one,

Update regarding this. Fitted a brand new genuine Fiat cap and all is fine now ? thanks guys

Great that the problem was just with the cap itself and you caught it early!