Aircon Difficulties

[chimaera]

Looking for some advice here.

 

About 2 years ago, I had to replace the hub in my aircon compressor (see below) as the frangible link had broken. Now the same thing has happened again, and I'm wondering what to do about it. The compressor has been a bit noisy (sounds like an old fridge rattling away) since I bought the car 4 years ago, and I'm wondering if this is normal or not, and whether it might be better to just replace the compressor? I'm open to DIY'ing it but I'd need someone to point me in the direction of some decent aircon service tools, and what's needed to collect the old refrigerant as it's removed (I'm reluctant to just vent it to the atmosphere).

[J.R.]

You need to start with a manifold set, about £30, then a vacuum pump, maybe £70, then the big cost, £230+ for a 13kg cylinder of R134a if you can find an Eastern European seller who will sell to an individual, post Brexit this might actually be easier.

 

That has been my investment so far (a bit hazy on the prices) the next big investment and one that is a step too far for me is the euipment to recover the R134a gas, that is scarily expensive.

[langers2k]

I'd be tempted to speak to a local garage and see if they can empty the system, let you make your repairs and then check/refill...

[Breezy_Pete]

When the last repair was done, was the system evacuated and refilled during/after that work (even though it may not have seemed necessary)?

 

Wondering if there's some water or other contamination in the system that's causing the compressor to struggle.

If that were removed, the present compressor might be OK with new pulley.

[chimaera]

4 hours ago, J.R. said:

You need to start with a manifold set, about £30, then a vacuum pump, maybe £70, then the big cost, £230+ for a 13kg cylinder of R134a if you can find an Eastern European seller who will sell to an individual, post Brexit this might actually be easier.

 

That has been my investment so far (a bit hazy on the prices) the next big investment and one that is a step too far for me is the euipment to recover the R134a gas, that is scarily expensive.

I'm in Ireland so getting stuff from an EU supplier is an option. That said, by the looks of it by the time I'm done spending money on hardware, I'm most of the way to what I'd pay a garage to refill it.

 

1 hour ago, Wino said:

When the last repair was done, was the system evacuated and refilled during/after that work (even though it may not have seemed necessary)?

 

Wondering if there's some water or other contamination in the system that's causing the compressor to struggle.

If that were removed, the present compressor might be OK with new pulley.

I didn't touch the system at the time, just swapped out the hub. I've seen someone mention that low refrigerant level can cause juddery noises from the compressor, so maybe it needs a regas and it'll be ok.

[chimaera]

The thick plottens. I took a closer look at this this evening, on the assumption that the hub had failed the same way it did two years ago I was planning to stick it back together with some Araldite 2014-2 until I can get a replacement shipped to me.

 

It was not the same failure though. The splines in the hub had stripped! It was a real pain to get off as there was nothing I could use to counterhold the compressor spindle while I undid the bolt. In the end I drilled into the hub enough to be able to grip on the shaft and got it out, to discover the stripped splines.

 

Given the current high temperatures we're getting, I wanted to get it back running some bit. The compressor spindle turns quite freely, no indication that anything's up there. I used a trick we've sometimes used at work to make adapters to grip unusual objects with a ratchet: I put a layer of vegetable oil on the compressor spindle splines, and put some Araldite inside the hub on the splines, then reassembled the hub. The Araldite should mould itself to the shape of the splines on both sides when it sets, and the veg oil acts as a release agent for the Araldite later when I need to remove it and fit the replacement hub I've just ordered.

 

I think I'll get it regassed then once it's back up and running fully.

[J.R.]

I was going to suggest that the hub may have stripped but as it had sheared in the first place I thought there must be some foreign object inside the system being chewed up by the pump., the replacement hubs are made of cheese, to have any chance of them working for any length of time the hub needs fitting with a good quality Loctite bearing fit, the same goes for new compressors from China (& most branded ones actually come from there) the hub needs removing and loctiting, often you will find it was barely more than finger tight.

 

I dont hold out much hope for your oil & Araldite attempt, I get where you are coming from but have been there and got the T shirt, its not the power transmitted by the drive that causes the failures (and the resistance is far more when pumping) but the non constant velocity of the crankshaft drive, the constant stress reversals even after being damped by the dual mass pulley and serpentine belt, the slightest bit of play or give in the cheese material or Araldite & the splines will fret away.

Edited 16 July, 2021 by J.R.

[J.R.]

If you still have your old sheared hub you may be able to make a good one out of the two, I had to do that on my last car as the original hub was the only one not made of cheese, I had had a new pump fail (hub splines stripped) plus a replacement hub, re-using the original worked for a year until I sold it, who knows if it has held up since.

[chimaera]

I have a new hub ordered, I found a place in Italy that actually carries Zexel spares rather than aftermarket knock-offs, so I only need the Araldite to last a week or two. It's also one of the industrial grades of Araldite, not the consumer-grade sh!te and it's pretty strong stuff having used it at work a fair bit. Long term I'd expect fretting to do for it as you say, we've seen this ourselves at work, but it lasts longer than you might think.

[chimaera]

My Araldite fix lasted 10 minutes

 

I guess trying to deal with outdoor temperatures around 28 C was too much for it.