Avgas Posted June 18, 2014 Share Posted June 18, 2014 I accidentally left my compressor on for 2 days and while using it this morning, it seized. It appears the oil has run out. There's no oil visible on the workbench so it's not a leak. I don't know much about the compressor at all and wouldn't have a clue how to go about restarting it, save for refilling the oil, or who to take it to should the problem be more serious. Everything I've read online suggests seizing due to lack of oil has serious consequences and my worry is that it won't get going again. Does anybody have any experience with this kind of thing? I don't want to spend money on expensive oil unless there's a chance it'll get going again. This is my compressor: Any help/suggestions appreciated !! Andre Link to comment Share on other sites More sharing options...
Steve27752 Posted June 18, 2014 Share Posted June 18, 2014 I think your only option is to buy a new one. Link to comment Share on other sites More sharing options...
depressed lemur Posted June 18, 2014 Share Posted June 18, 2014 If the piston has seized it will be cheaper to buy a new one than try to repair. The only way to find out will be to strip the head off the piston, if it is seized the chances are the bore will be scored which means it being rebored. worth it on a car, motorbike etc, but not always the cheapest option on a compressor. Link to comment Share on other sites More sharing options...
Rick Brown Posted June 18, 2014 Share Posted June 18, 2014 Strip the head and see. Could be salvageable if your mechanically minded. It shouldn't take too much effort, and you can clean up the bore fairly easily. I've done it in the past on me old motorbikes. Rick. Link to comment Share on other sites More sharing options...
bzn20 Posted June 18, 2014 Share Posted June 18, 2014 Oh dear! Sounds like curtains. Did you have to top up with oil quite often then? If I left mine on it would go to the cut off and come back on when below ?psi/Bar. Not something that goes on forever. Link to comment Share on other sites More sharing options...
Jetblast Posted June 18, 2014 Share Posted June 18, 2014 Unless the compressor was left running with the regulator open (?), it should only have charged the tank & then stopped running. If the regulator was open, or if there are any significant leaks it would continue to run until the thermal protection switch kicked in (or out rather) & stopped the motor, the thermal protection switch should then take somewhere in the region of 30 minutes to restore power to the motor & this process would continue until rectification or failure. It could be seized, but the compressor would have had to burn quite a bit of oil to reach this stage (or passed it into the receiver) - if the oil level did get low enough that the oil wasn't transferring heat from the piston to the sump & casing, the thermal protection switch may not be any the wiser as it relies on oil transferring heat to the sump/casing to operate.... Assuming that you have retried it to rule out thermal protection being temporarily active, I would check if the piston is seized - you will need to remove the outer square steel case (4 or 6 bolts along the bottom edge), remove the black motor cover retaining bank (bolt or hex socket at rear) & then check for motor rotation. The highest part inside the motor casing is the cylinder / piston / valve assembly & it will have a shaft protruding from the top - this should rotate by hand without much resistance. If the shaft doesn't rotate, you could try forcibly rotating it with a spanner or grips (it may / may not have flats) & see if you can free it - if you can, give it a few rotations manually, put some fresh oil in & see how you get on. It is possible that it may work satisfactorily, but if it does, you will most likely find that performance & fill times aren’t what they used to be & that it passes oil more readily…… Link to comment Share on other sites More sharing options...
Val_Ukraine Posted June 18, 2014 Share Posted June 18, 2014 (edited) I appologise for my English is not so good. Hope, you'll understand, what I want to say. There are many reasons that could stop the compressor. If it worked for two days, the first thing that could happen - the overheating protection has triggered. Your compressor housing is sealed (I believe, it is of the type, used in home refrigerators), so the oil could escape only through the outlet hose. If you do not see any traces of oil at output, (and I can not see any oil in the flask of the air filter), it is necessary to do the next: 1. Disconnect the compressor from the mains and let it cool down (for 30 minutes at least). 2. Make yourself sure that no thermal fuse is triggered. If it is - then press the fuse knob (it should be somewhere there on (or in) the black box!). 3. Try to run the device again. In any case, if you don't see any oil traces - you must not fill it in. The worst case is if the compressor motor is faulty or the piston is really seized.Then you'll better buy the new one Or you can find the same kind of compressor in an old domestic refrigerator. Edited June 18, 2014 by Val_Ukraine Link to comment Share on other sites More sharing options...
Avgas Posted June 18, 2014 Author Share Posted June 18, 2014 (edited) Thanks for all the input. Quite a lot to digest for someone as technically challenged as myself. I'm willing to give these suggestions a try - the worst I can do is break it, but I seem to have managed that already so no loss there. Just to answer some questions: Did you have to top up with oil quite often then? If I left mine on it would go to the cut off and come back on when below ?psi/Bar. Not something that goes on forever. No, I've had the compressor for two years or so and only ever filled it once. It usually does as you describe, cutting off and only coming back on when the pressure drops. I only realised it was on when I happened to walk into the garage and hear it click on. The only way to find out will be to strip the head off the piston Strip the head and see I would check if the piston is seized - you will need to remove the outer square steel case (4 or 6 bolts along the bottom edge), remove the black motor cover retaining bank (bolt or hex socket at rear) & then check for motor rotation Would that be the large roundish component (black in this case with the silver 'join') ? Make yourself sure that no thermal fuse is triggered. If it is - then press the fuse knob (it should be somewhere there on (or in) the black box!). Thanks for your suggestions. I don't have a clue what to look for. I've removed the cover on the black box top right in the picture and couldn't find anything that looked obviously like a fuse. Edited June 18, 2014 by Avgass Link to comment Share on other sites More sharing options...
Rick Brown Posted June 18, 2014 Share Posted June 18, 2014 Do you have a mate who tinkers with engines or cars Andre? Compressors are quite simple things really, and would be well within the capabilities of someone with a knowledge of engines. Worth a try for a pint to a mate. Rick. Link to comment Share on other sites More sharing options...
Jetblast Posted June 18, 2014 Share Posted June 18, 2014 Yes, the motor is the large black lump in the centre with the silver band round it. Can't be certain due to the age, but the thermal protection switch is generaly under a plastic cover on the the outside rear of motor casing, which contains the start relay & the switch - the switch is usualy round in shape & held against the casing by a bit of sprung steel. The majority of thermal switches are of the slef resetting type, but again due to age, it may as the OP has suggested have a push in reset switch. Link to comment Share on other sites More sharing options...
colin Posted June 18, 2014 Share Posted June 18, 2014 If, and it looks like, the same a a fridge compressor, there is a start/run relay with a thermal cut out built in, they are not normally a fuse as such and don't blow but cut out (as in the name) and reset when cooled down.It you switch it on and you hear a hum followed by a click that is the compressor trying to start and the (click) is the thermal cut out going open circuit,it could be either the start device that has failed or in the worse case the start or run winding that has gone open circuit. Do you know of a domestic appliance engineer that does refrigeration (system repairs) they could check it for you If its just dead check the plug fuse as it has been known for people to fit a too low rating fuse 5amp and these can fail over time due to the load being taken on start up, most fridges have a 13amp fuse fitted even though the wattage is low due to this. ps In you picture it shows the on-off switch, the relay/cut out would be attached to the compressor in a box, follow the lead from the switch to the compressor and it's under there And a obligatory safty warning it's mains voltage around there Link to comment Share on other sites More sharing options...
Avgas Posted June 18, 2014 Author Share Posted June 18, 2014 It you switch it on and you hear a hum followed by a click that is the compressor trying to start and the (click) is the thermal cut out going open circuit That's exactly what happens when I turn it on, Colin. I've since opened the compressor up and (I think) identified the piston: That's the piston, right? It's jammed tight and no amount of hand power can shift it. I'm thinking of popping some oil in there in the hope it loosens it. Thing is, the entire workings seem to be well lubricated I could jam something in from the other side and try to shift it but I don't want to damage the bore (?) further. See pic: How much force can I use to try to dislodge it? Rick, I have one mate who knows his way around cars (he's a mechanic at Rolls Royce so hopefully he knows what he's doing) but he's away at the moment, so it's up to me if I want this thing working any time soon. Link to comment Share on other sites More sharing options...
colin Posted June 18, 2014 Share Posted June 18, 2014 I'm not sure about that part, the ones I work on are welded together It's a sealed unit, even so I doubt you'ed be able to turn it by hand even if it wasn't seized.Have you looked to see if it's got any oil in there, what does the manual say about checking the oil and topping up as there must be some sort of indicator so you don't over fill it. Has it got a tank, or was it running continuous for two days Link to comment Share on other sites More sharing options...
Avgas Posted June 18, 2014 Author Share Posted June 18, 2014 There is an oil level indicator and it's never been over filled. I neglected to keep tabs on the level and ran it dry I'm afraid. As for the tank, I always assumed the housing I've just opened was the tank !! (I know very, very little about these things). But it seems it doesn't have one, though it does store air somewhere if it allows me to spray for a minute or so before kicking back on again when the pressure drops? Bah, I don't know if it has one or not mate. Thanks for all the input guys. I'm going to cover it all up and look at it again in the morning. Link to comment Share on other sites More sharing options...
bzn20 Posted June 18, 2014 Share Posted June 18, 2014 Good point about reset button/switch. Is there a reset somewhere? It would stop it running if overheated and/or just needed resetting. Just a thought. Link to comment Share on other sites More sharing options...
colin Posted June 18, 2014 Share Posted June 18, 2014 Ah if it was run dry it's not looking to good, top it up with oil, leave for a while and try to turn the piston with something that will give you a little more leverage without damaging it, you may get lucky their fairly robust bits of kit. The click is the thermal overload tripping out, it does this not only on heat(running a lot) but current drawn on start up, and with a seized compressor that's going to be high Link to comment Share on other sites More sharing options...
AngloSaxon Posted June 18, 2014 Share Posted June 18, 2014 Looks very much like this fridge compressor: Taken from this thread: http://forums.lr4x4.com/index.php?showtopic=9710 From the problems you describe, it sounds seized and I doubt whether it's salvageable, good luck though Mike D. Link to comment Share on other sites More sharing options...
Avgas Posted June 19, 2014 Author Share Posted June 19, 2014 (edited) Well... Success !! After letting it sit all night 'soaking up' some oil, I managed to free the piston with a few light taps of a hammer. Put it all back together, switched it on and felt a jet of air. Now to get some more oil !! Thanks for all the help everyone. If all goes well it will have saved me the cost of a new compressor. Edited June 19, 2014 by Avgass 1 Link to comment Share on other sites More sharing options...
Jetblast Posted June 19, 2014 Share Posted June 19, 2014 All's well that ends well! Keep an eye on oil consumption as it may be higher now than it was previously. Link to comment Share on other sites More sharing options...
Avgas Posted June 19, 2014 Author Share Posted June 19, 2014 Definitely. I wont be so lazy about it in future. On the subject of oil - is the Sincom oil the only suitable oil? Bearing in mind my compressor isn't under waranty (I believe using any oil other than Sincom voids the waranty), is there a cheaper, as good alternative? Link to comment Share on other sites More sharing options...
little-cars Posted June 19, 2014 Share Posted June 19, 2014 It's the only one I would use, it's about £16 for a 500ml bottle. I think the beast needs some TLC and it's cheaper than buying a new one. Paul Link to comment Share on other sites More sharing options...
Avgas Posted June 19, 2014 Author Share Posted June 19, 2014 Yea, point taken. I'll go with that then. Thanks. Andre. Link to comment Share on other sites More sharing options...
bzn20 Posted June 19, 2014 Share Posted June 19, 2014 I bet you're relieved,well done! 1 Link to comment Share on other sites More sharing options...
Rick Brown Posted June 19, 2014 Share Posted June 19, 2014 Just think, you were going to buy a new compressor! You've saved enough to buy yourself a pint or two! Rick. 1 Link to comment Share on other sites More sharing options...
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