Air compressor won't start?

[wow]

If the pressure gauge is a single component and it's not the joint that's leaking, then obviously the gauge is. You may have damaged it, of course, or it may just be another one of those things where it just failed.

If you want, here's a quick test - screw in a plug of the right size, using three layers of teflon tape on the threads. Try the compressors again - it'll be fine since the gauge just READS the pressure (unless it has the regulator knob/pressure adjustment as part of the gauge - I can't tell). The compressor should come up to pressure (although you won't be able to 'read' that) and shut of automatically. If it does and there are no leaks, you've found your culprit.

That gauge is also not repairable, but those kinds of gauges are usually pretty cheap - like around $10 over here. You might even be able to find one at your equivalent of a 'big box' store / home center in the plumbing area, as they are often used on well pressure tanks as well as air lines. Take the old one along so you can match the threads and pressure scale.

 

[festivus]

Thanks wow.

I know it's not the gauge. I have tried two other gauges and still leaks only on the one side 

Without replacing the while assembly into which the switch and gauges connect I think I just need a way of dealing with leak better than Ptfe tape?

Thanks.

 

[wow]

Thanks wow.

I know it's not the gauge. I have tried two other gauges and still leaks only on the one side 

Without replacing the while assembly into which the switch and gauges connect I think I just need a way of dealing with leak better than Ptfe tape?

Thanks.

Sorry - missed that you'd tried multiple gauges.

It's not often the fitting, and you should be able to see that leak by looking into the threaded 'socket'. If you don't see anything I'd try the temporary plug like I suggested above. If nothing else, it would give you better visibility into the area where it's leaking.

Honestly, something sounds 'off' about that leak. I'm now thinking a cracked manifold or something...and I think the gauge is hiding it?

 

[festivus]

Thanks - it starts leaking around 6 bar and can feel it around the join. I'm tempted to try some thread lock or similar. Or perhaps get some thicker PTFE tape (looking online there's a yellow PTFE tape for gas joints).

I'm not quite sure what you mean by plug - it's an odd size - do you mean a bolt or similar. Doubt I'd have one of the right thread. The fact that three pressure gauges all leak around the join makes me feel it's at the join - but maybe as you say it's just near the join. Will also take a closer look.

Thanks again for your help!

 

[nclemmons]

Is the female side cracked?  Sounds like it could have split from over tightening of the gauge maybe?

You can plug it with what looks like a 1/4" or 1/8" pipe plug.  You can get them at most hardware stores.  Just take the gauge with you and you can compare the size to the male end of the gauge.

 

[festivus]

Thanks neilc. Maybe you're both right - I just assumed the joint wasn't coming together tightly and needed some more tape or something else that I don't know exists!

Will examine carefully tomorrow and see if I can see a crack in 67 below. If so I may have to cut my losses on this!

Thanks again.

 

[festivus]

Doh! Didn't notice last night in dark - crack round the back.

I've put some epoxy on the cracks in a botch last attempt. Will probably have to order part highlighted red - but doesn't look easy to replace so may just give up - grrr!! Anyone want to make me an offer  on very good compressor ?

 

[wow]

That appears to be nylon which is going to be difficult to get any glue to stick to, BUT...

I've had some success in a similar situation using an epoxy glue and over the top of the round part with the threads inside using a stainless hose clamp. That way the glue only has to block the crack while the clamp holds the piece together.

Here's the kind of clamp I'm talking about:
[attachimg=1]
Hope the picture of the clamp helps make sense of what I am trying to explain?

 

[Bohdan]

If the epoxy doesn't work you could try a Loctite product that is designed to wick into small metallic cracks and seal them. It is called Loctite 290, it is designed to lock assembled nuts and bolts and to repair porosity in welds.

 

[festivus]

It is metal. Epoxy didn't work - the fitting has completely broken now. That hose clamp would have been a good idea!

I'm going to try and get a replacement t-bar.

Appreciate all the help.

 

[Tinker]

It is metal. Epoxy didn't work - the fitting has completely broken now. That hose clamp would have been a good idea!

I'm going to try and get a replacement t-bar.

Appreciate all the help.

Doesn't epoxy expand a little.  We used it (I think it was an epoxy product) many moons ago to seal leaks in concrete walls.  I tried several different products for the problem, so do not remember which was best.  All of the sealers did not work.  the ones that expanded as they set up did the best job. 

Not poking at you, but isn't it great that we often resort to the best solution after all else fails. And some solutions actually make the problem worse.  Been there/done that.
Tinker

 

[festivus]

Thanks Tinker - missed your post.

Just for completeness, I thought I'd post the end result. Ended up changing the stem (which included the regulator). And all is good! So many thanks for everyone's help! Ended up costing almost £80 - but that was my mistake for blowing the stem screwing in the pressure gauge which is made of monkey metal!

Just a couple of points for anyone reading this - be very careful tightening anything into this weak metal. And also be wary of wrapping loads of PTFE tape to seal an air leak. The combination of too much tape and over tightening - albeit just by hand without tools - can easily break this type of metal.

I had loads of joints to redo so rather than use PTFE tape and risk a leak or worse I bought some thread sealant which is designed for this type of work. I used Loctite 577 - and would highly recommend it! Although not cheap!

[attachimg=1]