Tryed the methed john trevino spoke about I pulled the non-return valve off cleaned it still the same pull it out again took some sand paper sanded the plug reinstaled non-return valve works like new thanks for the info john saved me from taking compressor to the shop
Youor problem is actually the unloader valve. Your pressure switch is an older style Condor MDR21 (http://www.google.com/imgres?q=condor+mdr21+pressure+switch&hl=en&biw=1244&bih=739&tbm=isch&tbnid=SpfaC0uYVDGONM:&imgrefurl=http://www.bettervac.com/hitachi-881575-pressure-switch-condor-mdr-21.asp&docid=QTBY4coa024BpM&w=242&h=242&ei=qi2PTsbDKZCutwe2vMGsDA&zoom=1). The check valve is connected directly to the tank and the feeder line for the unloader connects to it, as well as the main line from the compressor pump. doing a little research on google you should be able to find one for less than 20 dollars. Or you can replace/upgrade your pressure switch to a newer model, which is shown in most of the manuals and parts break downs. Yours is probably the pre 2005 model. If you still need more assistance please repost with additional questions.
Tim
The most common problem with ec12 compressor is the non return valve part # 881-581 (check valve). The purpose of this valve is to hold pressure in tank. When the valve begins to leak, the air will be discharged thu unloader valve at the pressure switch. Simple repair, order valve from www.toolpartsdirect.com or you can use generic valve from www.grainger.com Good luck and post again if you have other question.
Sorry about the delay, had death in family. Refrence #53 is the check valve, its purpose is to keep compressed air in the tank. If it leaks the air will come out of the unloader which is built-in to the pressure switch ref. #63. The unloader valve/stem works like valve stem in bicycle tube. The unloader is not a replaceable part (generally not sold seperately because it hardly ever fails before the whole pressure switch fails) This link will show you a generic switch that I use for replacement instead of factory part http://www.northerntool.com/shop/tools/p.... In the photos you will notice the unloader connection that is referenced as connection (B). If you feel that your unloader stem is bad then you will need to replace the whole switch unless you find a used part at local repair center. So to answer this question; ( It has a brass fitting ( ? check Valve?) where nylon air line from air tank inserts into the presure switch) this is unloader built in to pressure switch.
Most ec12 compressors suffer from leaking check valve, easy to check remove large tubing and spray soapy water, it is leaking, replace it and problem solved, good luck
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Hello. here is a link to a free downloadable owner manual and parts list. http://www.hitachi-koki.com/manual_view_export/pdf_manual_view.do?implementationWorkNumber=312&partsCode=C99128411&model=EC10SB(SL)+/+EC12&marketSeq=4
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Thank you for your answer. I already have the parts diagram and the parts list for the Hitachi Air Compressor EC 12. I need a specific answer to my question.
The brass part is not shown on the parts diagram or listed on the parts list.
After research on the internet, and review of many websites, I believe that this part may be a Pressure Check Valve. Again, not shown on the parts diagram nor listed on the parts list.
This brass part is 1 25/32 in. in length by 1/2 in. in diameter, and has a machined groove on the end that inserts/attaches into the pressure switch(EC 10 SC) at the place shown as "B" on the parts diagram, and is secured in place by a 2.5mm hex screw. The nylon hose is secured into the end of this brass part and the other end of the nylon hose attaches to the non-return valve.
This brass part inserts into the pressure switch BELOW fitting number 63 on the parts diagram at the place labeled "B".
Can someone please help me with this? Please do not refer me to another diagram, or list, unless it shows and lists the name and part number that I am asking about.
My compressor is a Hitachi EC 12. It has a brass fitting ( ? check Valve?) where nylon air line from air tank inserts into the presure switch (EC10SC) shown as "B" on parts diagram. This fitting constantly leaks air out of a small hole on the side of the fitting where it is recessed into the back of pressure switch at "B" and secured to the pressure switch via a small hex key. This brass fitting is 1 25/32 inches long. Is this a check valve? Can you tell me exactly what it is? Do you know the part number to replace it?
The last "expert" referred me to parts diagrams on two different websites. As I have said, this part does not show on the parts diagram, and is not listed in the parts list. But I assure you that it does exist, and it is the cause of my compressor malfunction. Please help me.
The brass part that connects the air line to the pressure switch is the part that is leaking .The unloader switch is at the tank. This brass fitting(part?) is at the other end of the air line. Connecting the air line to the pressure/on off switch. This is where the air is coming from. How can the unloaderswitch coming from the tank be bad if the air leak is at the other end of the nylon air line? Do you know what this fitting that connects the nylon air line to the pressure switch is called, and what it's function is? Why is this fitting leaking air if the unloader switch is bad? It makes no sense to me. I am not an expert, but I am a logical and methodical person. Could you please explain thi to me? Thank You!
Thank you very much for your patience and your detail.
Sorry about your personal loss. I'll say a prayer.
I will order a non return valve, install it, and go from there.
I will let you know the results.
Thank you again.
DrBill47
I have replaced the switch including the check valve with an identical new part. I have also replaced the non-return valve with a new replacement part.
when I turn the compressor on, everything works, but the air leak at the end of the new check valve where it inserts into the switch remains unchanged.
I believe that I have replaced all of the parts from the tank to the regulator valve, to no avail. I have even tried another regulator valve, but of course it made no difference.
Is it possible that I received a bad check valve with my switch?
What else could cause this problem? A bad replacement part?
I am very frustrated. Could you please help me with my problem?
I have tried everything that you, and the "experts" before you have recommended.
What next?
Thanks,
DrBill47
I replaced the switch, check valve, and non-return valve with new parts. The problem persists, unchanged.
DrBill47
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