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.
This is for a small, pancake air compressor used to drive a nail gun.
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
... Read morewithout 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.
Removed head, cleaned off old gasket, replaced valve plate and lower and upper gaskets, retightened head bolts attached feeder tube. Turned on compressor allowed to get to full pressure, checked for leaks.
1. Disassembled the compressor.
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
... Read morehead(reed valve) to be sure they don\'t get out of place.
Took shell off removed connecting rod and piston. Then I removed and replaced cylinder barrel. Installed piston ring then reassembled the compressor.
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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.
Removed cover from compressor.
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 g
... Read moreaskets. 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.
Replaced cover, connecting rod, piston ring, cylinder and torx screw. Put the piston and rod in the cylinder and connect the connecting rod. By replacing these parts it fixed the problem.
gave up. put in new valves but after the 3rd piston seal I quit. They are way to stiff to get into the piston cylinder without tearing. tried grease, oil and heat but when you try to get it into the cylinder it tears. The last one does get pressure up to 70 lbs so i\'ll quit with that.
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_WW_1.gif "Part Location Diagram of AB-9040019 DeWALT PISTON RING")
_WW_1.gif "Part Location Diagram of AB-9040019 DeWALT PISTON RING")
