Reed Valve Failure – Air Compressor Reed Valve Troubleshooting

Published Categorized as Air Compressor Troubleshooting, Air Compressor Valves 11 Comments on Reed Valve Failure – Air Compressor Reed Valve Troubleshooting

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A compressor reed valve failure is a common complaint sent in by people that have an air compressor that continues to run, but that will not build air pressure.

This page will provide you with how you can fix the reed valve failure, useful YouTube demonstrations on removing and replacing it, as well as existing reader questions and responses.

Table of Contents

Fixing an Air Compressor Reed Valve Failure

On behalf of all of us, our thanks to Jason Antonacci of North Augusta, SC for sending in a post and a diagram along with it, addressing the issue of air compressor reed valve failure. The diagram (shown below) is from the manual for Jason’s compressor.

The concept will apply to any compressor that uses some sort of reed valve setup for intake and high pressure air compressor valves.

Here is Jason’s drawing, his questions, and my response.

compressor reed valve failure - reed valves
Expanded view of compressor pump

I have an air compressor that recently stopped building pressure beyond 40 psi. After reviewing your troubleshooting steps and documentation I had hope that the compressor could be rehabilitated. Thank you for your site, it has been an invaluable resource.

On disassembly I discovered the top, yoke shaped reed had failed: snapping in the middle. The bottom, tongue shaped reed is OK. If I can locate reasonably priced replacement parts, I’ll rebuild.

This brings me to my question. All gaskets appear to be a fibrous material (cardboard?) sandwiched between adhesive material. Not all of the gasket came off cleanly, so bits are stuck here and there on both surfaces.

What is the suggested method for re-finishing these surfaces for a new gasket? I was thinking a wire brush attachment on my drill. Do I need to be concerned about debris in the cylinder and if so how can I prevent/remove it? Lastly, what kind of lubrication?

Apparently this reed valve design is prone to failure based on the number of similar complaints. Maybe I’ll build a Franken-compressor, mounting the 5hp motor w/ a belt driven compressor of another make?


Thank you both for the compliment on my website, and for the photo/sketch of your compressor head.

Reed valve failure is a common complaint about many of the lower cost, DIY type air compressors on the market.

I would be hesitant about wire brushing the surfaces due to the potential for damage to the metal, and consequential difficulties in re-sealing. If you proceed in so doing, work slowly and carefully so that the metal isn’t scratched.

Consider using a liquid/cream cleaner like “Goo Gone”, or similar, that will dissolve adhesives and sealants. Read the directions and use them with care, please.

I would very much be concerned about getting debris into the cylinder. Before you cover it with clear plastic or the like, and/or before you reassembled it, blow it out with compressed air (difficult when your compressor is disassembled, I know) to ensure that there is no debris in there to possibly scratch the cylinder surface or damage the seals.

Others have manufactured their own compressor reed valves out of paint scraper blades. See the sitemap page for a link to those directions.

If you’re looking to Make Your Own Air Compressor Reed Valve then please visit our guide! Otherwise, continue scrolling down this page for useful reed valve replacement demonstrations.

Useful Reed Valve Replacement Demonstrations

I have picked out a couple useful youtube demonstrations on how to go about removing and replacing your air compressor reed valves.

FAQs (Frequently Asked Questions)

What happens when a compressor reed valve goes bad?

If a compressor reed valve goes bad, the compressor will not build pressure as the air is likely to escape through the intake/inlet rather than out the cylinder through the discharge/outlet.

What are the symptoms of bad reed valves in a compressor?

The symptoms of bad reed valves are that the compressor will struggle to build pressure past a certain point or it will not build any pressure at all. It is therefore imperative to check the reed valve plate if you

Additional Troubleshooting Pages

Air Compressor Types Troubleshooting

Air Compressor Part Specific Troubleshooting

Reader Questions and Responses

Repairing / Replacing a compressor cylinder head.


by Bob
(Herndon VA)

I have an older Sears home-type compressor (2HP 7-8 gal tank) It wasn’t operating properly and I found a broken reed valve on the pressure side of the head.

Sears - Craftsman 2 HP air compressor - newer version
Sears – Craftsman 2 HP air compressor – newer version

It appears to have been riveted in and therefore not an easy home fix. New replacement heads seem not to come as an assembly, so even if I bought one I would still have the riveting problem. Is there a source for used parts Suggestions?


Hi Bob, and welcome to you and others from Virginia.

The downside of buying “house brand” DIY compressors is that they don’t normally lend themselves to repair.

Check with the store and ask them who repairs their compressors under warranty, and then ask those folks.

f the valves are riveted, it’s possible they are not designed to be replaced… a throwaway in other words. I expect you can drill out the rivets, but yup, a lot of work.

Used parts? Possibly. Maybe a visitor can comment on that.

If you have any questions regarding air compressor reed valve failure then please leave a comment below, with a photo if applicable so that someone can help you!

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I have an older craftsman compressor ,25 years, #919.155730. The reed valves gave out. You can no longer purchase the reed valve plate and casket by it self. Is there anywhere I can go to have the old reed plate repaired. I hate to throw the unit away. The compressor and tank are still in good shape. Can I purchase a replacement compressor and reuse the exsisting tank. What would you do. Thank you.

My D.I.Y. repair: I made a replacement out of a 0.3mm feeler gauge, cut to size obviously and no deformity during cutting. That gave me the exact thickness and strength to bend compared to the old ones. New is ideal but it wasn’t an option at the time. It was back to normal operation again thankfully and I could then purchase some replacements for when I need them again in the future.

Where can I find said Reed parts? It’s a Harbor Freight compressor. 21 gallon model # 47065. And are the things that look like silicone bumps included with the gaskets? And are the 2 items that appear to be alignment pins included? I lost one as seen in the picture?

Cory says “…are the things that look like silicone bumps included with the gaskets?” I think those are artifacts of assembly. “And are the 2 items that appear to be alignment pins included?” Probably not. You may have to fake it. AFAIK, no one has found the parts for this particular machine, but I certainly could be wrong. Go look at reed valves. Maybe include harbor freight and/or the model. If that doesn’t yield, look for something that looks right. Contact the seller and ask if they know if it will fit your machine, and/or get measurements so you can… Read more »

I replaced my reed valves with ones I found on EBAY for the harbor freight compressor.

Lucky you –
Were they specifically said to fit the 47065?

Last edited 2 years ago by Doug in

I have a Campbell Hausfeld 125 psi 13 gallon 4 hp. It only fills to 20 psi keeps running will not go past that. I took up the top today to look at the piston and seen that as you look at the picture one of the pieces broke off. Now I cannot say for sure if it did not break off as I took it apart but I doubt if that is the case.

Not likely you broke it. You do want to be sure to recover it from wherever it went.
And depending on your exact model, you want to get new valves, perhaps only available as a valve plate.
Otherwise, just figure out a way to block the hole where the broken piece goes. Then it will work, but not as fast.

Good luck.

I have it’s fairly new 21 gallon 2.5 hp air compressor my question is my reed valves are burnt scorched but not broken what causes that and should they be replaced as a result I’m having trouble with the compressor as it builds air but the check valve located on motorhead is becoming much hotter than I believe it should be as well as the compressor itself keeps blowing fuses I understand most courses are air leaks behind or near the check valves which I do not have the check valve opens and closes as it should so I’ve been… Read more »

Not knowing the make or model creates a big problem trying to help you determine the cause of the compressor problem. From the symptoms I suspect that it’s been run long and hard. True? Could you please identify it and add a photo or two of the problem area for all to see and help? Thanks.

“… it builds air but the check valve located on motorhead…”
I presume by motorhead you mean the pump? That’s normally at the tank. While you’re giving the model, maybe also give the part key number you refer to, or a picture of what you’re talking about.