Genuine Bostitch replacement part, this item is sold individually.
This part is installed on top of the piston/connecting rod.
Its purpose is to create a seal in the cylinder so that air can be pump into the compressor tank.
If this part wears your compressor will not pump the air properly. This is a wear part and it is advised to keep an extra one on hand.
Piston Ring AB-9040019
OEM part for: Bostitch
Part Number: AB-9040019
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Product Description ?
- Classification: Part
- Weight: 0.01 lbs.
- Shipping: Ships Worldwide
Frequently Purchased Together ?
Compatibility
This Piston Ring will fit the following 11 machines. Confirm this part works with your model, and view the detailed model diagrams and repair help we have to offer.
Bostitch
Show More Compatible ModelsThis item works with the following types of products:
- Compressor Parts
Customer Part Reviews ?
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Customer Repair Instructions ?
All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part.
Torx screw failed, piston came apart destroying piston ring and ring cover, also scored cylinder.
Tool Type
Compressor
Difficulty
Easy
Time
1-2 hours
Tools Used
Screwdriver, Socket set, Wrench Set
On disassembly, take photo or do drawing to show where parts go, especially reeds in the head..
Assemble new piston parts, use thread lock on torx screw.
Pass connecting rod up and through new cylinder barrel with connecting rod sticking out the end without the flange. Then hold on flat work surface with piston end down. Stiff piston ring is hard to bend so it will go into cylinder. I put some WD40 on the cylinder to make it easier. push down on cylinder while rocking piston a little until piston ring compresses and piston slides into cylinder. Ring should be concave toward cylinder head.
Assemble piston, connecting rod and cylinder into compressor through the cylinder frame, lightly tap connecting rod onto bearing. Don't let piston slide out of cylinder barrel.
Fix connecting rod to bearing with connecting rod clamping screw, thread lock would be good here too.
Install fan onto crankshaft with socket head screw.
Assemble cylinder head parts, taking care to keep reeds in proper place. Use your photo to make sure you get things right. Use new gaskets. Head parts and gaskets form several layers. While holding layered parts together, install on compressor with cylinder head bolts. Two inside nuts are captive in frame, outside nuts require 10mm box wrench to tighten. Install cylinder-to-tank tube and tighten. Run compressor briefly (keeping body, fingers, etc. away from the fan and connecting rod in case something comes loose) and see that pressure starts to build. If so, reassemble cover halves using the long bolts and screws. You will have to take the hose connection off to get one cover half on so release the pressure in the tank if any. Job done. Would have taken less time, but doubted whether reeds stayed in place and took head apart again. Also make sure you order all gaskets and parts you'll need up front. I didn't and it cost me more for shipping. ereplacementParts was fast on the orders and had the right parts. When a piston lets go, it is best to replace all the parts from connecting rod to piston cover and likely the cylinder too as it gets scored from the piston without ring banging around. Doesn't take much banging to do it.
Loss of compression generation
Tool Type
Compressor
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
Screwdriver, Socket set
Blown Reed valve & supply tube to tank
Tool Type
Compressor
Difficulty
Medium
Time
30-60 minutes
Tools Used
Screwdriver, Socket set, Wrench Set, Allen wrench, fine fine sandpaper
Parts Used
I think it's on the right track to work again.
Compressor would not build pressure above 80 psi.
Tool Type
Compressor
Difficulty
Easy
Time
15-30 minutes
Tools Used
Screwdriver, Wrench Set, Nutdriver, Torx bit
compressor not building pressure
Tool Type
Compressor
Difficulty
Expert
Time
More than 2 hours
Tools Used
, oil,grease,heat
Parts Used
Fan/connecting rod evidently slipped off bearing destroying fan and putting excessive wear on piston ring. Also fan pieces sucked into prison and melted onto reed valve.
Tool Type
Compressor
Difficulty
Easy
Time
15-30 minutes
Tools Used
Screwdriver, Wrench Set, Adjustable Wrench, Star drive & Allen wrench set.
Removed head and broken fan.
Pushed piston up thru top of cylinder
Cleaned piston head w/ brass wire rush to remove melted plastic. Also cleaned cylinder w/ fine steel wool. Replaced piston ring, reed valve & fan.
Tap connecting rod onto bearing. You may also want to order the head gaskets. Do not overtightened heads.
Be sure to tighten all fittings to prevent air leakage.
Reassembled cover, plugged unit in and it pressured right up to 140psi.
drive belt broken, bad crank brgs
Tool Type
Compressor
Difficulty
Medium
Time
1-2 hours
Tools Used
Screwdriver, Pliers, Socket set, Wrench Set, snap ring pliers
Burned off the timing belt and damaged the piston ring during repair.
Tool Type
Compressor
Difficulty
Expert
Time
More than 2 hours
Tools Used
Screwdriver, Power Drill, Socket set, Wrench Set, Nutdriver, torx. propane torch, allen wrenches
Bearing went out.
Tool Type
Compressor
Difficulty
Medium
Time
30-60 minutes
Tools Used
Screwdriver, Pliers, Socket set, Wrench Set, Adjustable Wrench
Connecting rod bearing failed and it threw the rod.
Tool Type
Compressor
Difficulty
Medium
Time
30-60 minutes
Tools Used
Screwdriver, Pliers, Socket set, Adjustable Wrench
2. Discover what I needed and ordered parts.
3. Had to take the reed valve (head) off to install the connecting rod and piston seal.
4. Tapped the rod bearing on the crankshaft.
5. Installed the fan
6. Put it back together.
Be extra careful when working with the head(reed valve) to be sure they don't get out of place.
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Our customer service team are at the ready daily to answer your part and product questions. We have a dedicated staff with decades of collective experience in helping customers just like you purchase parts to repair their products.
All our part reviews are solicited directly from other customers who have purchased this exact part. While we moderate these reviews for profanity, offensive language or personally identifiable information, these reviews are posted exactly as submitted and no alterations are made by our team.
All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part. While we moderate these reviews for profanity, offensive language or personally identifiable information, these reviews are posted exactly as submitted and no alterations are made by our team.
Based on data from past customer purchasing behaviors, these parts are most commonly purchased together along with the part you are viewing. These parts may be necessary or helpful to replace to complete your current repair.
All our installation videos are created and produced in collaboration with our in-house repair technician, Mark Sodja, who has helped millions of eReplacementParts customers over the last 13 years repair their products. Mark has years of experience in selling and repairing both commercial and residential products with a specialty in gas-powered equipment.
This data is collected from customers who submitted a repair instruction after replacing this exact part. Customers can rate how easy the repair was to complete and how long it took. We aggregate this data to provide a repair rating that allows customers to quickly determine the difficulty and time needed to perform their own repair.