Jamie Young
New member
I'm having a heck of a time trying to get the gas piston off my SA93. I've tried several tools but just can't seem to get a grip on the thing so that it actually turns.
Any tricks?
Any tricks?
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AK piston
- Thread starter Jamie Young
- Start date
Try AK-47.net.I'll bet you'll get a lot of responses there: http://www.gunsnet.net/forums/forumdisplay.php?f=77
Good Luck...
Good Luck...
Dfariswheel
New member
You did drive out the retaining pin????
If so, pad a big vise with some heavy brass or copper inserts, grab the center section of the rod, and unscrew it.
If not, the retaining pin goes sideways through the bolt carrier just behind where the piston and carrier join.
The pin is riveted in place, ground flush, then finished over, so it's often almost impossible to see.
Also consider, that the piston might even be welded on.
Some less expensive AK's came in with welded pistons.
If so, pad a big vise with some heavy brass or copper inserts, grab the center section of the rod, and unscrew it.
If not, the retaining pin goes sideways through the bolt carrier just behind where the piston and carrier join.
The pin is riveted in place, ground flush, then finished over, so it's often almost impossible to see.
Also consider, that the piston might even be welded on.
Some less expensive AK's came in with welded pistons.
Jamie Young
New member
I see no retaining pin.
I see a small ring on the left side but it is located where the gas pistons threads would be and not between the threads and actuall rod part.
I'm totally stumped.
I see a small ring on the left side but it is located where the gas pistons threads would be and not between the threads and actuall rod part.
I'm totally stumped.
Dfariswheel
New member
Again, the retaining pin is ALMOST impossible to see, since it's ground flush and finish is applied over it.
The Bulgarian SA and SLR rifles are well built and finished, and the pins are DIFFICULT to find.
What you'll need to do is remove the finish on the SIDES of the bolt carrier, or op rod assembly, just behind where the piston joins the carrier.
The pin is "about" 3/8" back from the piston, on the carrier.
The pin goes passes through the carrier and the piston, right through the threaded part.
The "ring" you see on the left MAY be the locking pin.
Again, it's "about" 3/8" back from the joint.
The pin is riveted, or mushroomed over to lock it in place, and in most cases all you'll see is a vague "shadow" or slightly different color that indicates where the pin is.
Again, the pin is often VERY, VERY difficult to see. It's there, but it's not uncommon for you to have real trouble finding it.
Once you've found the pin, make up a hardwood block with a clearance hole to pass the pin.
Brace the assembly on the block with the pin over the hole.
Use a STRONG pin punch, or better a cut-off "starter" punch to drive the pin out of the carrier.
NOTE: Due to the riveted pin's head, the pin may APPEAR to be larger than it is......start off with a smaller punch, until you can see just how big it is.
Where you get into trouble with these really tight pins, is if you allow the parts to bounce or move around.
If allowed to move or bounce, the force is dissipated, and the pin CAN "upset" instead of moving out, locking it tightly in place.
Once you've got the pin out, unscrew the piston.
Clean out the hole in the carrier and apply some rust preventing lube.
Screw the new piston in until it bottoms out with the flange against the carrier tube.
BACK THE PISTON OFF about 1/3 to 1/2 a turn. DO NOT leave it tightly screwed down.
Use a drill press to drill the hole through the new piston, being careful not to drill off center.
Make up a new locking pin. A nail makes a very good pin since it's strong enough, AND rivets nicely.
Make a small counter sink depression on both sides of the carrier pin hole.
These countersunk areas will give the new pin's rivet room to flow for a good hold.
Use a ballpeen hammer to rivet one side of the pin, flip it over and rivet the other side.
Grind or file the excess pin rivets off flush with the carrier, then apply new finish over the area.
NOTE: The new piston SHOULD be slightly loose and have a slight amount of movement.
This is to allow the piston to properly align itself with the gas cylinder.
This is why you have to back the piston off 1/3 to 1/2 a turn during assembly.
The Bulgarian SA and SLR rifles are well built and finished, and the pins are DIFFICULT to find.
What you'll need to do is remove the finish on the SIDES of the bolt carrier, or op rod assembly, just behind where the piston joins the carrier.
The pin is "about" 3/8" back from the piston, on the carrier.
The pin goes passes through the carrier and the piston, right through the threaded part.
The "ring" you see on the left MAY be the locking pin.
Again, it's "about" 3/8" back from the joint.
The pin is riveted, or mushroomed over to lock it in place, and in most cases all you'll see is a vague "shadow" or slightly different color that indicates where the pin is.
Again, the pin is often VERY, VERY difficult to see. It's there, but it's not uncommon for you to have real trouble finding it.
Once you've found the pin, make up a hardwood block with a clearance hole to pass the pin.
Brace the assembly on the block with the pin over the hole.
Use a STRONG pin punch, or better a cut-off "starter" punch to drive the pin out of the carrier.
NOTE: Due to the riveted pin's head, the pin may APPEAR to be larger than it is......start off with a smaller punch, until you can see just how big it is.
Where you get into trouble with these really tight pins, is if you allow the parts to bounce or move around.
If allowed to move or bounce, the force is dissipated, and the pin CAN "upset" instead of moving out, locking it tightly in place.
Once you've got the pin out, unscrew the piston.
Clean out the hole in the carrier and apply some rust preventing lube.
Screw the new piston in until it bottoms out with the flange against the carrier tube.
BACK THE PISTON OFF about 1/3 to 1/2 a turn. DO NOT leave it tightly screwed down.
Use a drill press to drill the hole through the new piston, being careful not to drill off center.
Make up a new locking pin. A nail makes a very good pin since it's strong enough, AND rivets nicely.
Make a small counter sink depression on both sides of the carrier pin hole.
These countersunk areas will give the new pin's rivet room to flow for a good hold.
Use a ballpeen hammer to rivet one side of the pin, flip it over and rivet the other side.
Grind or file the excess pin rivets off flush with the carrier, then apply new finish over the area.
NOTE: The new piston SHOULD be slightly loose and have a slight amount of movement.
This is to allow the piston to properly align itself with the gas cylinder.
This is why you have to back the piston off 1/3 to 1/2 a turn during assembly.