Quincy QT-5 for $25, help me fix it

[sld961]

I picked up a Quincy QT-5 pump for $25 bucks. It was in a woodshop. An air line broke and it ran for the weekend. The previous owner just replaced the pump to get back up and running. He said he thinks it might have warped a valve?

I got it home and played with it a little. It still turns over and pushes air out of the discharge. The oil is full, but a little dark.

I plan to get some pipe fittings so I can hook a pressure gauge up to the discharge and see how much pressure it builds by turning it over by hand.

What else can I check/test to troubleshoot before I tear it down?



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[oldmachinenut]

Are you in central Pa.?

 

[sld961]

Are you in central Pa.?

Yep.

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[oldmachinenut]

I just saw that on c-list last night for $50.00, do not need another compressor but damn near called

 

[sld961]

I just saw that on c-list last night for $50.00, do not need another compressor but damn near called[emoji23]

That's the one. I didn't need it either, so I offered him $25 bucks last week or so. He didn't get any other calls so he said come and get it.

Hopefully I can get it up and running cheap and easy.

I only have an extra 3hp motor. It'll work, but I'll have to keep an eye out for a cheap 5hp on CL next.

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[American Locomotive]

They have a 100% Duty Cycle, so I'm surprised it failed at all. If it has any problems, I'd also suspect it'd just be a bad valve, or a valve with some crud in it.

 

[sld961]

They have a 100% Duty Cycle, so I'm surprised it failed at all. If it has any problems, I'd also suspect it'd just be a bad valve, or a valve with some crud in it.

I called Quincy and they said pretty much the same thing, they said that it shouldn't fail by running for a weekend, or for a week for that matter.

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[MacMcMacmac]

If you can get full output pressure and about 40psi in the intercooler relief valve port I'd say your valves are ok. Reed valves usually need a bit of air velocity to work properly though, so no guarantees this test will be successful.

If you get no pressure in your intercooler relief valve port, you have bad valves in the LP cylinder. If you have full discharge pressure at the interstage safety relief valve port, you have HP valve problems. If you keep turning it over with the output port plugged you will reach full discharge pressure in the interstage eventually, so don't keep cranking on it.

Running it with a motor is the only real way to see what's what.

 

[The Tool Tyrant]

^^^^ Mac said it all.

That poor air filter element lead a hard life in that wood shop!

 

[sld961]

If you can get full output pressure and about 40psi in the intercooler relief valve port I'd say your valves are ok. Reed valves usually need a bit of air velocity to work properly though, so no guarantees this test will be successful.



If you get no pressure in your intercooler relief valve port, you have bad valves in the LP cylinder. If you have full discharge pressure at the interstage safety relief valve port, you have HP valve problems. If you keep turning it over with the output port plugged you will reach full discharge pressure in the interstage eventually, so don't keep cranking on it.



Running it with a motor is the only real way to see what's what.

Thanks! This is what I was looking for

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[sld961]

If you can get full output pressure and about 40psi in the intercooler relief valve port I'd say your valves are ok. Reed valves usually need a bit of air velocity to work properly though, so no guarantees this test will be successful.



If you get no pressure in your intercooler relief valve port, you have bad valves in the LP cylinder. If you have full discharge pressure at the interstage safety relief valve port, you have HP valve problems. If you keep turning it over with the output port plugged you will reach full discharge pressure in the interstage eventually, so don't keep cranking on it.



Running it with a motor is the only real way to see what's what.

If a valve is bad, can I fix or replace just the bad valve, or do I have to buy the whole valve plate?

Also, can I use a DIY gasket material to make new gaskets, or do I need to buy new gaskets?

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[The Tool Tyrant]

According to the ROC 203 (2006) parts manual, the valves are NOT sold separately. You must purchase the valve plate assembly #113946X.

You only paid $25 freak'n dollars for it...jeez, cough up a few bucks and fix it right!

 

[sld961]

According to the ROC 203 (2006) parts manual, the valves are NOT sold separately. You must purchase the valve plate assembly #113946X.



You only paid $25 freak'n dollars for it...jeez, cough up a few bucks and fix it right!

I certainly will if I have to, but at this point, I'm approaching this as a low budget project. I'll do it right, but if there's a cheaper way to do it right, I'll take the cheaper way.

I still have to source a 5hp motor, a 60 or 80 gallon tank, magnetic starter, etc. I'm in no hurry, so I'll wait until I find good deals on all of the parts.

Thanks for all the feedback.

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[The Tool Tyrant]

I certainly will if I have to, but at this point, I'm approaching this as a low budget project. I'll do it right, but if there's a cheaper way to do it right, I'll take the cheaper way.

I still have to source a 5hp motor, a 60 or 80 gallon tank, magnetic starter, etc. I'm in no hurry, so I'll wait until I find good deals on all of the parts.

Thanks for all the feedback.

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Seriously, the PO may have THOUGHT it had an issue, when in reality it could just be a clogged air filter. Install a new one (no, just don't blow it out!) before you do any further investigation work.

 

[Fallon]

You can run it with a lower HP motor if you put a smaller pulley on & run the pump slower.

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[sld961]

Seriously, the PO may have THOUGHT it had an issue, when in reality it could just be a clogged air filter. Install a new one (no, just don't blow it out!) before you do any further investigation work.

I'll try that.

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[sld961]

You can run it with a lower HP motor if you put a smaller pulley on & run the pump slower.

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I have a 3hp that I'm going to try. It's a 3450rpm, so I need a 2.4" pulley to get the right pump rpms. The smallest pulley I can find is 2.5". I doubt it will make that much difference, but I'll probably call Quincy to make sure that won't stress the motor to much.

The only other issue is getting enough belt contact to not slip on the pulley. I have a similar size pulley on my other air compressor motor for the same reason and doesn't slip, so hopefully I'll be ok. I should at least be able to hook it up to bench test the pump.

I also will need to fashion a bracket. It is a 182tc mount, face mount only, no horizontal mounting bracket.

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[sld961]

I hooked up my pressure gauges to try to get some readings. I couldn't build any pressure, so I pulled the pump apart. The at least one valve failed completely, the end of the reed was broken off. Both pistons had damage on the top from debris.

There are a couple of streaks in the cylinder walls, but nothing that catches a finger nail. They should be good if I hone them. Being cast iron, they didn't score much.

There is some damage to the to top of the pistons, but nothing that extends down to the rings. I'll sand everything smooth with some emery cloth and they should be good.

Bottom end spins very smooth with no noise.

I called the local Quincy rep and they want $238 for the valve plate and $25 bucks for each gasket. Like was mentioned, the reeds and bumpers aren't available separately.

Looks like I'll probably clean up the pistons and then put it back together and stick on the shelf until I actually need it. I can't justify $300 bucks to fix this thing. Maybe I'll keep an eye out on eBay for a deal on the valve plate, but I think my chances are slim, based on the limited stuff on there now for the qt5.



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[sld961]

I changed my mind on the valves. I'm never going to be ready to spend $300 to fix this, so I started to pull the valve plate apart to see what I need to replace.

I measured the reeds at 0.015". So I looked online and ordered some 0.015" high carbon steel stock (feeler gauge blades). I'm going to take a stab at making a new reed. It cost me $12 bucks, worth a shot.

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[The Cobbler]

what is the length x width of the reeds? just curious

 

[sld961]

what is the length x width of the reeds? just curious

I didn't measure them that way, I probably should have. They're about 3/8" wide, maybe 1/2", and maybe 3" long for the low pressure cylinder and maybe 2" for the high pressure cylinder.

I ordered a 1/2"x12" piece.

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[sld961]

I think I got it fixed. Made the new reed, pulled all of the other ones and cleaned the reeds and seats. Put it all back together and now I can get it up to 120psi spinning it by hand. It gets too hard to spin by hand.

I did the calcs on the sheave, and the sheave I have on the motor for my other compressor will work. Or it's 28 bucks for another sheave. I'll probably buy a new one so I don't have to pull the other motor off.

So far I have $37 into this. Not too bad.

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[The Tool Tyrant]

Hopefully, whatever the alloy makeup is and whatever heat treating process used on that feeler blade will allow it to make a bazillion cycles before snapping at the mounting hole!

 

[sld961]

Hopefully, whatever the alloy makeup is and whatever heat treating process used on that feeler blade will allow it to make a bazillion cycles before snapping at the mounting hole!

Yep, that's the unknown at this point. I'll have to wait and see. Worst case, I'm out $37.

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[The Cobbler]

good foo you. also interested in the longevity .

 

[vwpieces]

I acquired the same QT-5 pump on a compressor. Same broken reed valve.
I am in Central PA too. LOL.
No intension of paying Quincy $300+ for a part, when they used to sell the spring steel reed valves separatly. Guess some bean counter decided it was not worth the time to ship those small parts.
I found a valve plate from Compressor now for $110 but it seems to be delayed and not shipping
https://compressornow.com/online-st...incy-kt-valve-ay-repair-qt-5-part-2022127201/
Done some digging and found some 1095 spring steel strips on MSC. But at 25ft and $52 shipped... I guess that is 100X lifetime supplies of the 1/2X.015 roll.
Link is for 0.016in thick but they also have the 0.015... I do have a use for .016 as feeler gauge for VW points setting.
https://www.mscdirect.com/product/details/03343332

I will continue to wait on the CompressorNow order to see IF the parts show up.

 

[The Cobbler]

would be interesting to hear an update from OP on his homebrew reed.

 

[vwpieces]

Found the 1095 spring steel strips in 0.015 thick on ebay for $41.60 shipped and it was from MSC
copied the valve and have the whole compressor back together and running. Filled from zero under 6min.
Pump is still tired, needs high pressure side rebuild, con rod, piston, rings and rings on the LP piston. But its running again for about $120. Did get new gaskets for both sides of the valve plate ($40) and made my own gasket for under cylinders. New crank bearings too but I had some good German SKF on hand, originals were China.
Using Mobil Rarus 427 in the crankcase. $40 for a gallon.
Extra hole in the broken valve was a test to see if I could punch a hole in this material.


Cause I can't leave anything alone... I ported the valve plate. There was some nasty casting seam flashing in the ports and the edges were square. Smooth out now. Valve seating side still square, untouched.


While I was waiting for parts I plumbed the entire shop with air line, 12 air supply drops in a 25X50 space. Air supply lines are within 12ft no matter where I am in the shop. Each post of the 2 post lift now have a coupler also.

I frequent this forum and will update my valve repair.

 

[vwpieces]

My DIY valve update...
Had a box O parts waiting for a couple years. Finally got around to tearing back into the compressor pump. It worked so was lower on priority list.
New HP piston and rings for both pistons, gasket set and new grade9 bolts/washers were installed in April 2024.
The DIY valve is still in great shape and working. Made valve in late July 2021 and still working today.
But rings were really worn, worse than I initially recalled. But I also didn't have new ones to compare first time pump was opened.
They were pretty bad, but no real noticeable decrease in pump time with new rings. Under 6min for 80gal. It does need a new cylinder but that will never happen. $330 last I checked for the cyl.

Black ring is New. It didn't use oil.

 

[woodgeek]

Nice work on rebuilding on your QT-5 pump. I won a QT-5 at auction and am replacing the reed valves in my pump since I have no idea how many hours are on the compressor -- I can tell it's a lot. I was able to find the reed valves at a number of online retailers. I'm buying mine from IndustrialAirPower.com

Have you downloaded a manual for your compressor? I contacted Quincy and they sent me the correct manual, mine compressor is from 2012. My QT-5 originally came with a Honda engine (which didn't come with the auction) so it has a 30-gallon tank. I'll be using a 5hp motor from a different compressor so I need to replace the mag starter and pressure switch. I'm working on sourcing those parts now.