Master TC-20 question


Air-Valve Autobot!
Hi people

Yesterdey I buy (used) a cheap compressor MASTER TC-20.
Is portable , lightweight and silent compressor for the price , the only thing that bother me is that barely hold 18 PSI when use it with my Iwata revolution and 25 with my micron .18

Is that normal ? I was hoping that it could hold at least 35 PSI when operating.
Did some research on these m8 as never personally used one and the specs say 25 litres a min/0.8 cfm @ 57 PSI and working pressure is between 15-45 PSI, so yer you should be able to set it at 35 PSI working pressure no worrys, I assume you've tried to max the reg out and see what the highest working pressure you can get? It is a single piston and 25ltres a minute may see the thing running constantly to keep up if you paint fast but it could be a reg issue if its maxing out at 18 or the specs have been inflated which is often an issue with a lot of manufacturers as they always spec it on best case scenario rather than normal use...I didn't come across any real negative reviews suggesting similar issues so maybe it could be an issue with that particular compressor..Others may own one and know more m8..
Thanks for the answer Revel , with 18 psi I mean that no matter where I set the output regulator , above that , when I press the trigger to release air the motor start and the pressure drop to 18 instantly , seems that motor has no power to hold it more than that.
The best feature of this model I that has no pulsating air , even that has no tank , I can add one , but I don't think that help to raise the pressure
Mmmm, sounds like it could be a reg issue as they are supposed to be able to operate much higher by what I read..That's a pretty severe drop if ya start at 50 odd and it regs it down to 20 odd, normally most will only drop by 5 PSi at the most when triggered..Dunno on that one m8, may be an issue there or to use it ya may really have to reduce heavily so it is actually useable..I know it takes my silent quite awhile to regulate up as the guage doesn't really do anything instantly until I hit the last few turns of the regulator..Soz can't be more helpful on that one..
Thanks , you help me a lot.
I search for an intake air filter to check but seems that won't have.
Next I will serach for human mistake , Here we have 220v and the compressor work on 110v , so maybe the previous owner sell it to me with a too small transformer that can't supply enough power to let the compressor work correctly , I will check that next
I have that same compressor, Diego. Mine operates at much higher than 18 psi. I think Rebel is right, it's probably a regulator issue. You could remove your regulator and connect your airbrush hose directly to see if the pressure builds up higher.
Thanks Heliotropic !!

Sadly is not the transformer or the regulator , piston don't compress enough or the motor don't run at the normal speed .
^ Bugger.Hope ya get it sorted m8..By the way is it getting super hot? heat can affect the working pressure of air drastically..many don't realize how hot compressed air actually gets and it can reduce compression/cfm by up to 30-40% (To what it states on the specs) which could help explain it, even hotter you could be loosing as much as of luck..
Thanks Heliotropic !!

Sadly is not the transformer or the regulator , piston don't compress enough or the motor don't run at the normal speed .

The only thing that would cause the motor to run slower would be less voltage so unless you have actually decreased the voltage this is not the problem, if the motor was faulty it would wouldn't run at all or hum as if it were trying to turn but can't, if there is a leak somewhere it affects the sound the whole compressor makes making you think the motor is behaving different, it's possible that there is a hole or tear in the membrane or a gasket is broken, if it's leaking air inwards you wouldn't feel the leak from the outside, if you remove the piston cover there is a rubber ring goes around the top of the piston this could broken or cracked from age.
Last edited by a moderator:
I had one of those and it could only deliver about a constant 23psi when using a Badger 150. It then ran full time and overheat after 30 minutes. Unless you use low pressure and give the machine time to cool down, it's gonna be a nightmare to use.
I've got one like it and it sounds like something is off with yours, the compressors work well but have heat issues.
A fan will help a lot but you just have to give it some time to cool if it gets hot.
Coffee, snack, bathroom breaks give the fan time to bring the temp back down so you can get back to painting faster than if you don't use a fan.
I'm using my .2mm at about 10-12 psi and I haven't run out of air yet. I have to stop because the compressor gets hot.

Check it over for leaks around the vanes seal and the drain plug as well as the connections.

Thanks a lot to all for the help !!.

I'm a little confused , some people say that can make it work at more pressure , some that no more that 23 (similar to me) , and the factory say that must hold 45 PSI .
Most of all I feel something wrong with the air , even the 20 that show in the regulator feels lower that the 20 of my other compressor .
@Madbrush has a good point , I remember that keep my attention that the compressor lose pressure even i I don't use it , start every couple of minutes even without use it

Has anyone a user or technical manual that can send me ?
Great , thanks !!!!

Plus I comared to my oldfashion 20l compressor and when the regulator of the TC-20 read 18 psi , really are about 10 PSI :/
Great , thanks !!!!

Plus I comared to my oldfashion 20l compressor and when the regulator of the TC-20 read 18 psi , really are about 10 PSI :/

Air regulators are never that accurate at lower pressures unless they are really expensive, so you can assume they are lying, I don't even bother to look now I just go on feel.
Just a few thoughts from when I took mine apart to fix a leak.

You shouldn't need to take apart the motor, just take off the end plate ( 4 screws ) on the side with the vanes and you can see the piston, bearing and behind that the eccentric counter weight.

Remove the 4 cap screws from the vanes (cylinder head) fold it over the switch and expose the cylinder, plate and some large O rings.

I had some corrosion, or mishap by the previous owner, on the underside of the cylinder head that I took off with 800 grit sandpaper and eliminated a leak I had between the cylinder plate and head.

I removed and cleaned the o rings, cleaned and wiped a thin layer of synthetic grease on the cylinder wall and then wiped it off doing the same to the seal/rubber band around the piston.

Reassembled it and it runs like a champ. (be cautious about getting oil or grease on the counter weight shaft.) I did not remove the reed valve or the valve from the plate as I saw no reason

I added a second fan and I'm very pleased with the results.

If everything looks and runs right without any leaks I'd suspect the pressure switch.

Good luck with it, Jim