new (old compressor)

[Dean Wilson]

Hi guys, I am not sure if this is the right forum to ask but seems like a busy one so thought I would give it a try....

I have just bought a 100litre old compressor as my 50 litre one just isn't doing it for me with my air tools. One thing I have noticed with it is that it doesnt have a drain plug at the bottom but it does have a tap at the top with a copper pipe going to the bottom of the tank that expels water when compressed.

My question is, is this how water used to be expelled from tanks, or is it just some weird assed compressor that I have bought.

Quite a bit of water was expelled from it the first time i Opened it and it was quite dirty. Since then when I have emptied it, the water has been clear, I am hoping that this is a good sign.

 

[123hotchef]

its called a dip tube some have them at the bottom others have the dip tubes like that

 

[Dean Wilson]

cool, so they are totally normal and safe then? Do they work as well as a valve at the bottom of the tank?

 

[brightspark]

heres mine I use it as a portable tank and can be filled from the top tap . it has a dip tube down from it and is also used as the drain I use it for the end of line also and plug stuff in it gives extra cooling and a dry air supply

 

[MattF]

cool, so they are totally normal and safe then? Do they work as well as a valve at the bottom of the tank?

The water will be forced up the tube by the air pressure in the tank. My tank has a drain on the side, several inches from the bottom of the tank, with a tube to the bottom. It does also have a 1/4" BSP plug at the bottom too, but that's a devil to get to.

 

[Dean Wilson]

Thanks for your help guys.

I do have another question if anybody can help. It leaks oil at the pulley shaft on the compressor part, I am guessing it is some kind of seal but for me to get into the part that leaks I need to take off the pulley. I have done some research and it looks like I probably need a gear pulley, most of the research i did showed the pulley having some kind of mechanism to keep the pulley on the shaft, usually needing an allen key to loosen but mine doesn't have anything like that. I have put on a couple of pictures to show what it looks like, do I just use the gear puller or does that little piece of metal sticking in the middle have anything to do with it?

Thanks in advance for your help again guys, I'm sorry if my questions sound silly, I seem to have very heavy hands and usually put far too much force into anything I do so want to make sure that I do it correctly

 

[Hopefuldave]

That looks like a taper key, and like it has a notch in the sticking-out end to get a small prybar (or equivalent) into to pull the key, the pulley *should* just slide off once the key's out, may need some Thermal Engineering to get it to let go of the shaft though...

Dave H. (the other one)

 

[Dean Wilson]

thanks. Just been looking online and they look like a pain to get out without a specialised tool

 

[Hopefuldave]

If they have the notch, they're not that bad - a J-shaped end on the bar, a piece of steel on the flat of the pulley hub as a pivot (as close to the key as you can get). Good idea to make the J-shape out of fairly "mild" steel as you want the bar to bend before you pull the end of the notch off... A few taps on the hub with a heavy gentling stick while you lever can help too.

If all else fails, the key's probably soft enough to drill and tap the end, then you can do socket/washer/bolt as a puller, using the largest bolt size you're happy won't mean drilling into the shaft keyway?

Dave H. (the other one)

 

[Dean Wilson]

Great, I managed to find a "specialised" tool in the garage. A thin(ish) rod of steeel that i managed to get through the spokes and onto a notch on the key which released it with a few whacks of the hammer.

I have taken off the pulley, found the offending seal, lost my bearings inside the casing but managed to get them out again and now need some help with the following questions if anybody can help (BTW, I appreciate all the help everyone has given me so far )

1) I am guessing that the seal is just a standard seal and is just a matter of me measuring it and ordering a replacement online? Will the metal springy coil thing that was in the seal come with the new one or do I reuse the existing one? (picture below)

2) I removed the gasket, should I get another one, are they pretty standard or can I make one? I think I used some of that instant gasket stuff in a tube last time I fixed an engine that was leaking, will that do? (picture below)





3) It seems like there will be some kind of trick in getting all of the bearing back in without them falling out again or is it just a matter of me putting the round casing on while the compressor engine (not sure if that is what the piston thing is called) is on it's side. (picture of bearings below)


4) Now this one is concerning me the most. When I took off the lid that had the seal in I heard a little tinkle of metal on metal. Now it seems that there is a metal ring in the casing that is a bit too large for me to get out but I am not sure where the heck it went and how i get it back to wherever that is when I put it back together. I have attached a picture which shows it inside the casing.


5) hopefully the last question, when I am putting it all back together again, how much do I hammer in the key, I dont want to hit it too hard so that I can never get it off again but dont want to hit it too soft so that it falls out. should i put some lubricant in it like copper grease to make sure I can get it out easily or will that defeat the whole principal of how it works?

I know this is a bit of a long one and really do appreciate anyone who put's in the time to answer me. If I could email a beer or two I would

Cheers,

Dean.

 

[BarrieJ]

I can help with 1. 2. and 3.

1. If you can get a new seal, it will come with the spring, getting an exact replacement seal may however be a bigger challenge.
2. Replace the gasket with new, if you can't get a direct replacement, then buy a sheet of gasket paper/material off eBay and make your own.
3. The trick of assembling ball bearings back in a race is to smear enough grease over the race so that the ball bearings will stick to it, then reassemble.
4. Sorry, no idea what the thing was that made the metallic 'tinkle'.
5. I'm afraid one gets a feel for how hard to tap things and one person's gentle taps until you feel a resistance is quite difficult to describe unless that person is standing alongside you.

Best of luck.

 

[Dean Wilson]

Thanks for getting back to me Barrie, do i have any options if I can't get an exact replacement, can I recondition the existing one?

In regards to the 'tinkle', is it that you can't see the ring that made the tinkle in the picture or you are not sure what it is for? Greasing the bearings is a great idea, that doesn't sound too hard.

I've noticed that the seal has a metal ring in the front embedded into it, I am not sure if it belongs to the seal or is part of the compressor, do seals sometimes have a metal ring built into them?

 

[Dean Wilson]

ok, I've done a bit more digging and I think I now know where the ring that made the tinkle should be.

I took off the side panel and noticed that there was another large ring on the other side of the crank shaft, it seems to be around the crankshaft at the top end and round a pin at the bottom with small metal tabs stopping the ring from coming off the tab. The pin is removable from the outside of the casing if needed, which I did remove when taking off the seal thinking it was an oil drain.

I am guessing that they are there to stop the crank shaft from moving up vertically as it will be stopped by the metal ring, I would be interested to know if that was actually what they were for or something different but I have set the other ring so that it is the same.
I've uploaded a picture to show the positioning of the other ring at the side of the crankshaft that I havent had open.

 

[Bsmith]

Oil seals used to have a row of 6 numbers on them which referred to outer dia, inner dia and thickness of seal, quoting these numbers to a supplier got you the exact replacement.
You will see what parts belong to the seal when you get a new one.

 

[Bsmith]

Think that big ring is an oil carrier.

Looking at the bearing that is in place, I think you need to renew the other one, the balls are not supposed to come out. Probably the bearing has disintegrated and knackered the oil seal. Renew both and it will be fine.

 

[Dean Wilson]

the bearings are touching the crankshaft on one side and a circular extrusion on the other side, I think they fell out because I removed the plate where the crank sticks out to get the oil seal and it is the plate that contains the circular extrusion.

In regards to the oil seal, I cannot see any numbering on it at all. I have attached a couple of pics showing each side.

 

[Bsmith]

I also needed oil seals for a cement mixer gearbox recently and they had no numbers on them, meant I had to get them direct from the cement mixer manufacturer. They used to have the numbers on the face as in your first photo.
Sorry, I didn't think you got bearings where the balls contact and run direct on the shaft.

 

[Farside]

I can see an outer race(stuck in the housing bit you took off), middle ball carrier (where the balls are sitting next to) , and inner race (on the crankshaft). You need to get the outer race out, and the inner race off, take them down to a bearing stockist and let them measure them up. They'll advise you on a seal, too.

Chances are, they're all imperial, so you might have to wait a bit or pay more - not a fortune though, they'll still be reasonably cheap.

 

[brightspark]

oil seals and bearings I just take them to a supplier up the road. if they haven't got them they can get them in a few days at a reasonable price just take a sample in

 

[Dean Wilson]

thanks for all of your help guys.

I managed to get a seal from a local supplier who measured up the old one and got me an exact match.

Barrie J, the grease on the bearings to keep them housed before I got it assembled worked a treat, still took a few attempts as the odd bearing at the bottom kept falling out before I had it assembled.


Made my own gaskets, reassembled it and turned it on and no leaks!! The only problem now is that my gib key keeps working it's way out and the pully keeps sliding from the crank shaft.

Now the end of the crankshaft was still a bit oily from when I was putting it all together as was the Gib key as it was stored in a little pot that had a little puddle of oil in it. I have cleaned all of the oil off the end of the crankshaft, the gib key and hole where the crank goes into the pulley.

I will probably give it another try tommorow night, is there any trick in making sure the gib key grips well or could it be that i need a new key? i didn't think that i did as i didnt have to put a lot of force to get it out the first time and it was holding the crank pretty tightly before i took it out.