Air Conditioning Blew Up!

[RAIDER32]

11 hours ago, RB2004 said:

I'm a mobile air conditioning person.

This effects 1.6l mk2 focus petrols.

Cause I've narrowed down to timing belt and water pump replacements.

Pipe is not disconnected prior to starting job.

Engine is lowered down which stretches the hose weakening it internally or more specifically breaking the string reinforcement.

Then when gassed up refrigerant gets between the 2 layers of hose and ruptures the outer layer, it always fails near to the crimp because that's the it which gets stretched.

 

That is interesting!

As I pointed out on this thread I'd just had my cam-belt changed 2 weeks before, weather was cool so never tried the aircon.

It makes me wonder now whether I've coughed up £176 having something changed that was damaged changing the cam-belt.

When I looked at the damaged I couldn't figure out how it went pop there with metal braiding, but thinking it had been pulled/bent now makes sense.

 

I might email my garage this info,

There will be a few 2009 1.6 Focus going in for their 8 Year Cam-Belt service this year.

[RB2004]

Yep I always tell people now to tell garage to degas the aircon, undo the hose then recharge aircon after when having timing belt done now because I'm reasonably sure it's the cause, if you take a look at the design of the hose when it's fitted to the car you can see there's a bit of slack to allow for engine movement, but there's not really sufficient slack to lower an engine down a few inches without stretching the hose.

These hoses as you saw are reinforced. Before they can blow out the reinforcing has to fail, and the inner part of the hose tear slightly allowing gas to get in between the rubber layers.

Then once that happens the outer part will swell up then burst and split open.

But considering this problem only effects the 1.6 petrol engines it is likely to do with a repair procedure like timing belt as all vehicles have hoses from compressor to condenser in same way just slightly different shapes


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[greysquirrel]

Thanks for that info RB2004, you are dead right in what you say, I had my timing belt changed last year. Someone needs to add this to the common problems list as a sticky, or a lot of owners could be out of pocket!

[sonic113]

On 09/07/2017 at 1:17 AM, RB2004 said:

I came to that conclusion because the way the hose comes out the compressor is not uncommon, it's actually pretty common even if the pipe is a different shape.

But it always goes at the bottom just above where the crimped section joins the hose, and it is only 1.6 petrol mk2 focus which have the issue.

First time it happened to me, I remembered that there was a sticker saying timing belt had been changed with an Ina kit.

I gassed it, and bang it went.. customer asked what it was and needless to say as it wasn't split before I started then I had to accept liability as it blew while I was working on the car. It cost me a pipe and free fitting.

Then I started warning customers in advance of gassing these engines up and I came across 1 more which blew when I gassed it but customer had been warned in advance, another one where customer had it gassed elsewhere and it blew them they tried to say it was his compressor, another one which was already split before I started, a second one which split when somebody else gassed it up, and only thing all of those vehicles had in common was either timing belt or water pump replacements and when you look at the hose you can see that if you try to lower the engine down, say to help undo crankshaft pulley, it doesn't take much before the hose starts stretching.


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As mine needs a regas any would you recommend just removing the hose completly before i do the timign tbelt/water pump  and the replace the hose after thats all fitted? Then go for the regas. or just not dropping the engine too musch to strech the pipe.

[RB2004]

I recommend disconnecting the hose at compressor end before lowering engine.

If you look down from above at hose you can see that there is enough slack for engine movement but lowering engine more than a few inches will begin to stretch it.

I've heard of similar damage on the mercedes A class compressor hoses, not actually come across it yet myself but you have to lower back of engine down to do some repair procedures like alternators and starter motors. The hose gets stretched in a similar way and fails.

But I haven't seen one on an a class myself yet only heard about it happening.

1.6 focus mk2 though I've seen it time and time again.

To put into perspective how common these are to fail, trust first Parts who are owned by ford and use their massive warehouses to supply local dealers rather than dealers getting direct from ford distribution centre. Last year I asked how many they had in stock of this pipe and it was over 100.

They can't all be failing due to wear and tear, there's a cause, and timing belts are needed on every vehicle at some point or another making it a frequent part to fail.


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[RB2004]

Ronald J
Thats good information there, Im due to install a timing belt/waterpump kit in the coming weeks and also then to get a full regass on the AC so I will be sure to watch out for that pipe when installing the belt.

Garages are doing things like this all the time and very rarely accept responsibility.


First time it happened to me, customer heard the bang, and I couldn't argue it was already like it because it wasn't, that's why I ended up forking out for a new pipe out my own pocket and fitting it for free.

Sad thing also about it is I lost work potentially over it. Because they was given my number by a friend of theirs who's car I had recharged previously and they had a business and promised to give out my details to their employees... but after this happened to their friends car that was last I heard from any of them as it probably fed back to him I broke the air con.

But focus isn't the only car they do it to.

MK4 mondeo is also a sufferer, the high pressure filling pipe goes through a hole between radiator and headlamp; you need an extension adaptor to connect to it.

So what people who don't have the adaptor do instead is bend the pipe out to the side of the headlamp.

I see this all the time and consider it criminal damage deliberately damaging an expensive aircon pipe just because they don't have the proper tool adaptor and tell people that if their car comes back like that to demand a replacement pipe. Because it can lead to failure of the pipe they fracture where the pipe is soldered into the aluminium block that bolts to condenser.


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[greysquirrel]

Well it's all re-gassed and working fine now, thanks for the advice on this thread, I hope it helps a few others too!

 

[RB2004]

Just want to update on this.

I did a timing belt yesterday on one of these engines and I carefully tested this theory.

I found that the crankshaft pulley gets stuck on the crankshaft and requires a puller to remove.

To use a puller you have to lower the engine down.

When the engine is lowered down, by the time the top of the pulley is level with the bottom of the chassis leg the hose is at full tension.

Any further and the hose would become damaged internally under the weight of the engine (I carefully lowered it down on a jack to point I felt the hose was safe as a test... if it breaks I will be accepting responsibility.

After that I disconnected the hose.

But full engine weight on the hose and the mechanic pulling engine downwards using a puller on it.. that would definitely damage the hose internally and I feel I have proven it after yesterday's experiment.

So if the hose becomes damaged after a timing belt replacement, there you go that's why, engine lowered down and suspended by hose to get crankshaft pulley off.

Doesn't need lowering down to do anything else at all: that's only thing. Seeming how low mileage this car was, I was changing belt based on years but it's only done 42k miles in 8 years.

I'm assuming stuck pulleys are common. And require use of a puller.


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[sonic113]

On 26/07/2017 at 9:30 AM, RB2004 said:

Just want to update on this.

I did a timing belt yesterday on one of these engines and I carefully tested this theory.

I found that the crankshaft pulley gets stuck on the crankshaft and requires a puller to remove.

To use a puller you have to lower the engine down.

When the engine is lowered down, by the time the top of the pulley is level with the bottom of the chassis leg the hose is at full tension.

Any further and the hose would become damaged internally under the weight of the engine (I carefully lowered it down on a jack to point I felt the hose was safe as a test... if it breaks I will be accepting responsibility.

After that I disconnected the hose.

But full engine weight on the hose and the mechanic pulling engine downwards using a puller on it.. that would definitely damage the hose internally and I feel I have proven it after yesterday's experiment.

So if the hose becomes damaged after a timing belt replacement, there you go that's why, engine lowered down and suspended by hose to get crankshaft pulley off.

Doesn't need lowering down to do anything else at all: that's only thing. Seeming how low mileage this car was, I was changing belt based on years but it's only done 42k miles in 8 years.

I'm assuming stuck pulleys are common. And require use of a puller.


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Hey Ronald J

I havent been on in a wee while so Im just catching up with things and saw your post. Im due to do a belt on my 2009 focus 1,6 zetec and was wondering if you think of any other way to work around this issue apart from discontecting the hose? Im need to get my aircon filled anyways and plan to stick a water pump in while im at it so mayeb disconnceting it wouldnt be a bad idea and might actually leave things handier when doing the job, whats your thoughts?

[kpat]

If the air con pipes are open to atmosphere for any reason then a new  accumulator should be fitted before re-gassing. Moisture will have entered the system and the accumulator desiccant efficiency will be reduced. The moisture could cause icing and blockage at the orifice tube in hot weather and will also corrode the system.

[sonic113]

On 15/09/2017 at 3:37 PM, kpat said:

If the air con pipes are open to atmosphere for any reason then a new  accumulator should be fitted before re-gassing. Moisture will have entered the system and the accumulator desiccant efficiency will be reduced. The moisture could cause icing and blockage at the orifice tube in hot weather and will also corrode the system.

so best then not bother to disconnect the pipe maybe. I will have to just keep an eye on that pipe when working at the T.belt.

[mjt]

I stand to be corrected but I think it is an offence to deliberately discharge refrigerant to the atmosphere so if you want to disconnect the pipe you should take it to a garage or AC specialist and have the gas removed first.

[TomsFocus]

Correct.  It's also under pressure and can burn skin and eyes so best not to touch a working system.  

Personally I'd just take more care over watching the pipe doesn't get put under any strain.