Uploaded February 2024 | Updated September 2026, 3 weeks ago
If your compressor is not building pressure it could be because of a faulty valve plate or piston ring. Of course, there could be other reasons, but this is what I found in my case. In this video, I show you how I diagnose my Husky pancake compressor problems and fix them. The compressor pump on this unit is model number OL195. It is used in some Husky, Stanley, and Bostitch models and possibly others. The model number is clearly imprinted on the pump for easy identification.
Many oil-less air compressor pumps are built with a motor that spins a flywheel, which has a connecting rod and piston assembly that pushes air through a cylinder. This compressed air feeds into a valve plate and pump head. This assembly supplies air into the compressor through a check valve, which prevents the compressor from losing air through the pump head. The compressor pump is controlled by a pressure switch with built-in hysteresis. The hysteresis could be set for 25 psi with a max pressure of 125 psi. This would mean that the pump will kick on at 100 psi and turn off around 125 psi. But, what if the pump never shuts off? That's why compressors are supplied with pressure relief valves to trip at a higher pressure, like 150 psi.
The particular problem with my pump is that it builds up pressure to around 45 psi but doesn't exceed it. The compressor doesn't lose pressure, which means that the check valve is ok and all hoses beyond the check valve are good. The problem could be within my pump itself. Another problem is that the pump never shuts off since it isn't achieving the maximum pressure of 125 psi. This could result in damage to the pump and motor and could possibly create a fire hazard from overheating.
Now that I built a shed, I'm cleaning up my garage and moving stuff into the shed. After rediscovering this old compressor that I had sitting I remembered that I had intentions of fixing it. That's why we are here. I have since purchased a replacement compressor that performs much better. But, it's nice to have this old one as a spare. And I enjoy restoring equipment that can be fixed without spending too much money.
The parts diagram for your compressor and pump is almost surely available online. The OL195 diagram is available on several websites where you can order replacement parts. The model OL195 pump on my compressor was assembled using the single valve plate. I upgraded to the double valve plate, which also required replacing the connecting rod cap for the piston. The double valve plate kit part number is AB-9429999. You may also see model information such as Bostitch CAP60P-OF, which uses the OL195 pump.
The piston ring is available here: amzn.to/3wx9b3O
The valve plate assembly and cap are available here: amzn.to/3UKAP7L
To learn more about this repair as well as other repairs and projects visit U Do It™️ here: udoit.me/equipment-repair-husky-air-compressor-is-not-pressurizing
Tools Used in the Repair
Ball-End Allen Bits: amzn.to/48reDCE
Milwaukee Shockwave Impact Driver Bit Set: amzn.to/3wyEwmI
Loctite Threadlocker Blue 242: amzn.to/3T7EACV
Craftsman Mechanics Tool Set: amzn.to/3Iaz38g
Ridgid Drill and Driver: amzn.to/3UNqR5q
C-Clamp: amzn.to/49L2j1m
“As an Amazon Associate I earn from qualifying purchases.”
Video Chapters
0:00 My Air Compressor Will Not Pressurize
2:10 Evaluating the problem
3:40 Removing the head body to inspect valve plate
5:45 Valve plate has a broken valve
6:43 Replacing the single valve plate with double valve plate
12:00 Preparing to install new piston ring
14:04 Removing fan (reverse threads)
14:40 Removing connecting rod from flywheel bearing
15:18 Installing piston ring on connecting rod
15:55 Installing piston into piston cylinder and installing connecting rod onto bearing
16:49 Installing double valve plate and pump head
17:37 Installing fan onto flywheel (reverse threads)
18:25 Compressor now reaches 125 psi
Video Credits:
Video Production: U Do It™️ Studios a Division of No Cheese Records LLC All Rights Reserved.
If your compressor is not building pressure it could be because of a faulty valve plate or piston ring. Of course, there could be other reasons, but this is what I found in my case. In this video, I show you how I diagnose my Husky pancake compressor problems and fix them. The compressor pump on this unit is model number OL195. It is used in some Husky, Stanley, and Bostitch models and possibly others. The model number is clearly imprinted on the pump for easy identification.
Many oil-less air compressor pumps are built with a motor that spins a flywheel, which has a connecting rod and piston assembly that pushes air through a cylinder. This compressed air feeds into a valve plate and pump head. This assembly supplies air into the compressor through a check valve, which prevents the compressor from losing air through the pump head. The compressor pump is controlled by a pressure switch with built-in hysteresis. The hysteresis could be set for 25 psi with a max pressure of 125 psi. This would mean that the pump will kick on at 100 psi and turn off around 125 psi. But, what if the pump never shuts off? That's why compressors are supplied with pressure relief valves to trip at a higher pressure, like 150 psi.
The particular problem with my pump is that it builds up pressure to around 45 psi but doesn't exceed it. The compressor doesn't lose pressure, which means that the check valve is ok and all hoses beyond the check valve are good. The problem could be within my pump itself. Another problem is that the pump never shuts off since it isn't achieving the maximum pressure of 125 psi. This could result in damage to the pump and motor and could possibly create a fire hazard from overheating.
Now that I built a shed, I'm cleaning up my garage and moving stuff into the shed. After rediscovering this old compressor that I had sitting I remembered that I had intentions of fixing it. That's why we are here. I have since purchased a replacement compressor that performs much better. But, it's nice to have this old one as a spare. And I enjoy restoring equipment that can be fixed without spending too much money.
The parts diagram for your compressor and pump is almost surely available online. The OL195 diagram is available on several websites where you can order replacement parts. The model OL195 pump on my compressor was assembled using the single valve plate. I upgraded to the double valve plate, which also required replacing the connecting rod cap for the piston. The double valve plate kit part number is AB-9429999. You may also see model information such as Bostitch CAP60P-OF, which uses the OL195 pump.
The piston ring is available here: amzn.to/3wx9b3O
The valve plate assembly and cap are available here: amzn.to/3UKAP7L
To learn more about this repair as well as other repairs and projects visit U Do It™️ here: udoit.me/equipment-repair-husky-air-compressor-is-not-pressurizing
Tools Used in the Repair
Ball-End Allen Bits: amzn.to/48reDCE
Milwaukee Shockwave Impact Driver Bit Set: amzn.to/3wyEwmI
Loctite Threadlocker Blue 242: amzn.to/3T7EACV
Craftsman Mechanics Tool Set: amzn.to/3Iaz38g
Ridgid Drill and Driver: amzn.to/3UNqR5q
C-Clamp: amzn.to/49L2j1m
“As an Amazon Associate I earn from qualifying purchases.”
Video Chapters
0:00 My Air Compressor Will Not Pressurize
2:10 Evaluating the problem
3:40 Removing the head body to inspect valve plate
5:45 Valve plate has a broken valve
6:43 Replacing the single valve plate with double valve plate
12:00 Preparing to install new piston ring
14:04 Removing fan (reverse threads)
14:40 Removing connecting rod from flywheel bearing
15:18 Installing piston ring on connecting rod
15:55 Installing piston into piston cylinder and installing connecting rod onto bearing
16:49 Installing double valve plate and pump head
17:37 Installing fan onto flywheel (reverse threads)
18:25 Compressor now reaches 125 psi
Video Credits:
Video Production: U Do It™️ Studios a Division of No Cheese Records LLC All Rights Reserved.
