Floating piston wear - how much is too much?

[drcolyn]

Could somebody please tell me what the proper way is to evaluate floating piston wear. The Bauer workshop manual for big block compressors are very detailed about ring wear but does not adress the floating piston.
I am busy restoring a Bauer KA20 that was sold as scrap due to suspected consequential damage from an hydraulic lock. After strip down right to the sump I found all was as well as could be expected of a compressor that only ran 600 hours since 1976. What is worrying me at this stage is how the performance of this compressor could have dropped to the stage where such radical damage was suspected so I am trying eliminate all possible problems.(did I mention that the same "agent" sold them a new compressor shortly afterwards?)
Included are some photos. I had to take it in 3 sections so please have a look at the file names for orientation. (I am still working towards buying that DSLR camera when I can afford a housing as well) The compressor stopped working in 2005 and was standing outside for the last year. After I cleaned it the piston was sitting tight in the sleeve with the barrel tilted about 75 degrees but in oiled condition it slips back into the sleeve about an inch at the same gradient.

 

[CraigAClark]

That piston is scored badly and I suspect the sleeve is as well. I'd replace it.

Craig

 

[widget]

Hmmm, yeah, looks a bit scored to reuse even if the seal is good.

I test them by dropping the oiled piston into the sleeve, it should slide slooowly down on the friction of the oil, it should not stick anywhere, and it should not "pop" right through with no resistance.

I stand corrected but I seem to remember Bauer suggests a life of around 900 hours?? - I dont have the manual here and its late.

I run 2 K14 units and had endless issues with the floating piston / sleeve on one of them (remember Craig , probably gave you grey hairs!) until I found the issue was a slight undercut in the sleeve which allowed air back into the oil sight glass - I was at my wits end stripping the unit daily to look for the issue - my advice, save yourself a few days, weeks, months of headache and just replace the sleeve and piston - I know, Bauer parts in SA are hugely expensive, but if costs an issue there is a Lawrence Factor distributor in here who can probably help you with generic spares and filters, which anyway work as well as the original and are quite a bit cheaper, I have been buying a few parts and filters regularly from him and so far no problems.

Although, thats an old unit, I am guessing, he would probably have to bring those spares in on special order, doubt they would have em on the shelf.

 

[CraigAClark]

I know, Bauer parts in SA are hugely expensive, but if costs an issue there is a Lawrence Factor distributor in here who can probably help you with generic spares and filters, which anyway work as well as the original and are quite a bit cheaper, I have been buying a few parts and filters regularly from him and so far no problems.

I don't know who you are refering to, but not many can beat the prices I sell L-Factor filters and New Parts for! Check the link below and you'll be able to compare what you're paying for filters vs our filter prices. Don't see what you're looking for or need prices for parts, send me a PM. Either New Parts numbers or Bauer numbers.

Craig

 

[cbmech2]

Craig,
I am in the midst of buying a new Coltri MCH-6 and do not see anything listed for filters/parts on the website. Do I need to look it up using another manfacturer?

 

[CraigAClark]

Look under "Nautica", most folks use the X152412. Most of the larger machines would use filters from the "Posiedon" series. If your not sure, give me the Coltri part number and I'll get you the cross-over number.

Craig

 

[widget]

I don't know who you are refering to, but not many can beat the prices I sell L-Factor filters and New Parts for! Check the link below and you'll be able to compare what you're paying for filters vs our filter prices. Don't see what you're looking for or need prices for parts, send me a PM. Either New Parts numbers or Bauer numbers.

Craig

So sorry Craig, I was in a hurry and didnt read my post before hitting "submit".

A case of "fingers faster than brain" I guess.

What I meant to say was that there is a distributor for Lawrence Factor "here in South Africa" (think thats where the ambiguity came in ) - who I buy from on a regular basis and so far no issues.

I know you are also a dealer having followed your link previously.

Generally Yes, you are right, USA based dealers are cheaper if you convert currancy directly, but unfortunately freight, customs duty, local taxes and red tape here in SA make getting it here a real issue for the average Joe, so, for me anyway, its just a matter of convenience to buy it locally.