Engine making worrying noises

MouldyOldDough

OK Air con fixed - by local specialist - total cost £164 inc vat - it needed a refill but no leaks found - the reservoir was 50% empty - is it possible for fluid to escape from a sealed system ?

wongataa

MouldyOldDough said:

OK Air con fixed - by local specialist - total cost £164 inc vat - it needed a refill but no leaks found - the reservoir was 50% empty - is it possible for fluid to escape from a sealed system ?

It is really hard to make a car aircon system completely sealed.  All that vibration and heat from the engine can cause small leaks to appear at seal that can be fine under a static test with the car off.  This can let the gas leak out over time.

The gas also has some lubricants in it which can help keep the seals in good condition.  If the system isn't used much this lubricant is spread around the system and the seals can start to leak slightly.

If the systems could stay completely sealed garages wouldn't offer aircon regassing.

MouldyOldDough

wongataa said:

MouldyOldDough said:

OK Air con fixed - by local specialist - total cost £164 inc vat - it needed a refill but no leaks found - the reservoir was 50% empty - is it possible for fluid to escape from a sealed system ?

It is really hard to make a car aircon system completely sealed.  All that vibration and heat from the engine can cause small leaks to appear at seal that can be fine under a static test with the car off.  This can let the gas leak out over time.

The gas also has some lubricants in it which can help keep the seals in good condition.  If the system isn't used much this lubricant is spread around the system and the seals can start to leak slightly.

If the systems could stay completely sealed garages wouldn't offer aircon regassing.

Thanks - I had assumed that the gas "broke down" over time and that was the reason that it needed replacing.....? 

facade

MouldyOldDough said:

the reservoir was 50% empty - is it possible for fluid to escape from a sealed system ?

Anecdotally, my brother works at a fast fitting chain that do aircon refills. He says the newer cars with R1234YF refrigerant seem to need a regas after 3 or 4 years, wheras the older R134a were good for 8 or 9 years.

The newer systems also hold a lot less gas than the old ones did, so the effect of a minute leak becomes a problem quicker.