Fiat Ducato air suspension leak

[gypo]

Morning all,
I’ve got a fiat Ducato trigano tribute van conversion.
About 5yrs ago I fitted air suspension to the rear, all working fine but I’ve noticed over the last year that after about 2 weeks it’s losing pressure.
I’ve done the leak detector spray test but can not find any leaks, this may be to how slowly it’s loosing air.
Has anyone else had this problem and if so any tips please to solve it?
Thanks
D

 

[RichardHelen262]

The first place to check is the gauges as they can be prone to leak

 

[gypo]

Thanks, I’ve checked the valve on the gauge but not taken it apart so I might have a look at that next

 

[gypo]

Just checked the gauge and can’t find any leaks there

 

[mistericeman]

Between the 'bellows' on the bags themselves is another fave....
Sometimes only detectable by taking the bags up to max pressure and extension.

 

[gypo]

Thanks, I’ve taken them up to 60psi where normally I run them at about 30psi I’ll give them another spray in a bit

 

[witzend]

With the volume of air in the system and losing pressure over a couple of weeks its going to take some finding as thats a very little leak

 

[gypo]

Yes that’s what I thought

 

[argoose]

Mine are on separate lines. If I close the two valves a leak will only be on one side.
If you have the same two valve set up you can tell which side the leak is on. This will cut your searching in half

 

[gypo]

Thanks but mine are both on one valve

 

[witzend]

Theres leak detector fluid thats UV detectable for AC leaks wonder if it would show if you added a bit some of the adds on ebay suggest it has other applications

 

[gypo]

That’s not a bad idea, I’ll have a look into that.
Many thanks

 

[Deleted member 87193]

You could also use air tool oil. Squirt a fair bit in and when you find oil you should find the leak.

 

[gypo]

I thought about that but I’m not sure if it will damage the air line or rubber bellows ?
Good idea tho

 

[mistericeman]

Plenty of UV dye leak detectors out there...

We use them occasionally for fridge systems with hard to find leaks

 

[gypo]

Thanks I’ll have a look into it, not sure how I’d get it into the system tho

 

[witzend]

Thanks I’ll have a look into it, not sure how I’d get it into the system tho

Let the air out by removing valve add UV with squeezy bottle then re inflate

 

[gypo]

I thought of that but didn’t want to totally deflate it as I’d have to then support the rear not to have too much weight on the empty bags

 

[wildebus]

I don't know if it will be a factor or would matter, but I would wonder if introducing a liquid into the air system (I presume that is what is being suggested) may affect the gauges which are designed for an air system, not fluid.
Maybe not an issue at all but a consideration?

 

[mistericeman]

I don't know if it will be a factor or would matter, but I would wonder if introducing a liquid into the air system (I presume that is what is being suggested) may affect the gauges which are designed for an air system, not fluid.
Maybe not an issue at all but a consideration?

It's usually a very small trace amount of UV fluid...
Shouldn't be an issue (certainly isn't on the gauges on my refrigeration equipment)