Can a vibrating rubber hose safely rest again a stationary smaller metal line?

Question

I've recently had an AC system repair done on my car, since the AC clutch coil thermal fuse went out without a reason, and the compressor needed a new coil or it wouldn't operate at all.

However, i'm not satisfied at all with how the mechanic routed an AC rubber hose. He basically ran the clutch coil cable in a way so that it's pushing the rubber (no metal braiding, only rubber on the exterior) AC discharge hose against the adjacent liquid line, a much smaller aluminum pipe. I know for sure that the rubber discharge hose didn't touch the liquid line before the repair. It's a U-shaped hose.

The immediate result is more noise inside the car's interior whenever the compressor reduces its displacement to prevent the evaporator from freezing up (the rubber hose itself vibrates when i touch it with my bare hands, and the vibration trasmits to the liquid line and then to the evaporator inside the interior). And i can put up with this noise, it lets me know that the compressor is doing its job.

However, since the metal liquid line is completely stationary, but the discharge hose vibrates, and the compressor itself is mounted on the engine block, which wobbles (or no hose would have been used), i fear that the discharge hose might eventually develop a hole and then leak and need to be replaced (i haven't inquired about prices, but OEM AC lines are usually made of gold, you know, and it's an old car so they might no longer be available too, and junkyards usually don't have what you need right when you need it) or repaired with a new hose (provided i'm able to find someone willing to do it).

I've tried bringing this up with the same mechanic, but he basically shrugged me off and rudely told me to not worry about it, that no leak will develop. Judging this behaviour i'm not entirely sure he would be willing to replace the hose at his own expense, should his choice turn out to be a mistake in the end.

Am i right in my belief that the hose could get chafed this way? Should i try covering that hose in some way, or can i leave it alone?

Answer 1

As long as it's round on round, I don't think I'd have an issue with it ... it's when the rubber is against a sharp edge which I'd worry. This isn't the way I would have done it, but I doubt it's going to hurt anything. If you are worried about it, you can add a piece of sacrificial rubber in between the two parts where it's touching. The sacrificial piece would wear out, then need replaced somewhere in the distant future.

As far as the noise goes, the only thing you could do at this point is to slightly tweak the hard line so it stays out of the way of the rubber one. The only danger in this is, if you move it too far or kink it in the process, you've permanently damaged the line hard line, which could then develop a leak. You'd need to be very cautious in doing this. You could also use something like a zip tie to pull the flexible line out of the way and hold it in place away from the hard line. This approach would also take care of the wear on the part due to rubbing.

All-in-all, I don't think it's a big deal (as I stated). If left alone, it will probably run that way well longer than how long you own your car. You basically stated your car is not a spring chicken, so if you think it's a vehicle which will last you another 10-12 years, then it might be something to think about, and then only separating the two lines ... if you think it's only going to last you another 5 or so ... no big deal.