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Hoges
7th October 2014, 12:45 AM
Having recently extolled the virtues of replacing "like with like" I spoke too soon:mad:

Discovered the EAS compressor was "screaming in pain" but no pressure... this was a new compressor about 13m ago and has less than 6,000km since it was installed. The vehicle has had an enforced layoff for the past 5 months and was left in "high mode", but had slowly dropped to standard height over that time so the system is pretty tight.

A couple of minutes and had it out of the vehicle and the side off the compressor... there was evidence of finely ground swarf in the inlet chamber. There was a score mark around the centre of the cylinder on the outside... Connected a 12V battery and while the motor spun, the piston didn't move.

Closer examination revealed that the set screw which screws into the side of the piston counter weight and connects with the index flat on the motor spindle to provide drive to the piston, had sheared!

Do I put it back together and demand another under warranty or fix it...

I just happened to have a replacement set screw of exact size and thread ;)(salvaged from a trashed office photocopier many years ago... I distinctly recall several office admin staff rolling their eyes, while a couple of engineers grinned and helped themselves as well:p) this is not the first time a plastic lunchbox full of knick-knacks from that and other salvage exercises has solved an immediate problem!!) ...but, I digress

The internal surface of the piston and the piston seal were in vg condition with no evidence of scoring.

So I reassembled it with a dab of Loctite on the set screw and re-installed the compressor... and low and behold, having filled the tank the P38 rose majestically when the door closed.

As there was no evidence of thread sealer on the remainder of the set screw... I can only surmise that the screw had worked itself loose and became sloppy on the shaft... fairly rare I hope...

davidsonsm
7th October 2014, 07:24 AM
It's a great feeling when you can diagnose the root of the problem quickly and have the solution to hand. For no added cost. Wah hey. Great result.

wayneg
7th October 2014, 12:00 PM
Nice work, how much would that have cost at a Garage, not much change from $1000 I bet (new pump + labour + GST). Unusual for that screw to be loose, its always been ridiculously tight on every pump I have disassembled.
As for salvaging old screws etc, I am like you. Before anything goes in the bin I have a quick look for screws bolts springs brackets etc I can keep, its not just the money you can save its the time shopping for a random bit.

Hoges
7th October 2014, 01:04 PM
Nice work, how much would that have cost at a Garage, not much change from $1000 I bet (new pump + labour + GST). Unusual for that screw to be loose, its always been ridiculously tight on every pump I have disassembled.
As for salvaging old screws etc, I am like you. Before anything goes in the bin I have a quick look for screws bolts springs brackets etc I can keep, its not just the money you can save its the time shopping for a random bit.

Thanks Mate.. I have printed out your response in large font and added it to my tool cabinet door...as" Rule 6":D ...which I shall henceforth point to when questions are asked... to indicate I am not "alone" in this DIY world..:eek::Rolling:

daf11e
7th October 2014, 01:38 PM
Nice work, how much would that have cost at a Garage, not much change from $1000 I bet (new pump + labour + GST). Unusual for that screw to be loose, its always been ridiculously tight on every pump I have disassembled.
As for salvaging old screws etc, I am like you. Before anything goes in the bin I have a quick look for screws bolts springs brackets etc I can keep, its not just the money you can save its the time shopping for a random bit.

Yes wayneg ...if you can find that bit at all!

Hoges
7th October 2014, 04:34 PM
That's what a large kitchen table is for...you empty the "Hope Chest" on it and sort through for the exact bit! :p