Hi barbarron,
Yes it just pushes over the pin. Hope that helps.Good luck.
Tinker

Hi there,
The check seal will slide up from the bottom of the cylinder and completely cover the holes in the sleeve. Be sure that the thicker part is pointing up, and that the seal is lightly oiled before you up slide the seal onto the cylinder. I hope this helps,
Gene

I have the same problem, I opened the tool up to find the driver pin assembly broke at the pin holding the driver to the piston. It should be item #122 on your schematic. But the problem is you/we need to buy the whole driver assembly kit, item #60030 not just the driver and piston. I have had this tool for 6 years and this is the first replacement I have had to do. When the driver breaks from the piston it stays at the nails, and doesn't return to it's reset position.

Clean the gun and replace the upper piston bumper.

I've had this nailer for about 10 years. Mine started to do the same thing, not returning back far enough to pick up a new nail. When I opened it up the piston stop was broken, part #886113. I'm ordering a new one. I think it will cure the problem.

It is possible that the Piston Stop has shattered. As the unit gets older the plastic pin stop will get brittle and fail. Remove the 4 screws from the top cap and disassemble. If you see plastic debris, this is probably the problem. Refer to the parts breakdown in this section and order the new parts. When reassembling, be cautious of the o rings, they are a tight fit and will tear if improperly installed.

You may have broken the check seal. Without that, the piston will not retract all the way causing a misfire. Also check to see if there is a piece of nail stuck in the nose.
Let me know how it goes.

Well...I got tired of trying to figure it out. It is now on Ebay. I started the bidding at $30. You win some and lose some. :) Thanks for the help.

Hello Retired1,
The check seal covers the holes on the cylinder, with the "wedge" part pointing up. Hopefully this will take care of your problem.
Gene

[QUOTE=genek;8731]Hello Retired1,
The check seal covers the holes on the cylinder, with the "wedge" part pointing up. Hopefully this will take care of your problem.
Gene"

thank you for your help, will place the check seal in that location and try again after getting my new parts

I suggest you do a complete cleaning and rebuild of the unit. I dont mess with just doing a driver rebuild , the complete overhaul takes care of everything and its very easy to do.
unit need porter cable part #903789 complete overhaul kit

heres a little info on how they work
link removed

Let me add to my question. When I took the gun apart I could pull the cylinder up about 2" or so to the point the small holes were outside the main gun body. I did not want to use excess force to pull the cylinder out. Is the cylinder suppose to slide out out of the main gun easily? Also if I replace the bumber and can not slide the cylinder out do I force the bumber through the bottom of the cylinder or top of the cylinder? Any tool recommendation for removing cylinder and bumber and reinstalling.

Robert

The contents of these maintenance kits seems to be complete mystery. I can find no site that says exactly what is included. For 903789 / 60075 some sites say bumber included and other say order seperately. 90367 / 60030 I think is piston, gasket and bumber. Also say a 903756 / 60080, not sure what it contains. Does anyone know the exact breakdown of what is included in these kits. I do not want order a kit to find out the bumber or something else is not included.

Thanks,
Robert

I was able to remove the piston, but now have an additional question. Everything looks to be good shape. The seal can slide up and down. If I slide it all the way up the part 127 cylinder space sits on top of the seal and blocks the air holes. Is that were it sits. Or maybe the design is such that at certain points it is suppose to block and at certain points it is suppose to be below the air holes. Any info would be appreciated. I think I am first just going to disassemble clean and regrease. Any suggestion of the right grease to use.

As you may have already discovered, the Porter Cable FN 250A finish nailer is a huge POS!
I had shot approximately one hundred nails with mine when the Nose Cushion P/N 429 totally disintegrated. After about three hundred nails it would only fire once. I had to manually reset for each shot. Disassembled the gun and found that the Piston Bumper P/N 114 was a pile of crumbs. I don’t expect equipment to last forever but, with so little use? I would describe this as a “Toy”, not a “Tool”.

Sorry to hear that you have had such poor success with your gun. My experience with mine has been very different. I have owned a FN250a for around 10 years now and have had nothing but trouble free use. My gun is primarily used in a home woodshop but I have also installed trim in 3 basements, a family room and several bed rooms. It has not been used professionally by any means but it has definitely had some use. Out of curiosity, what brand of oil do you use when you lubricate the gun? That is the only thing I can think of that could cause the bumper to fail prematurely.

-UtahAV
-Mark

replaced all my bad seals along with the plastic piston stop, gun fired fine for about 30 nails then quit working. driver will fire once and then won't retract,pulling air hose off then manually pushing driver back there is air pressure against the driver so for some reason there is no air release after firing the gun, HELP any ideas

Welcome bulletpusher. Usually the piston bumper is to blame when your driver isn't retracting, and since yours is shattered it's a good bet that replacing it will fix your problem (part #886122, $20.67). As for the trigger valve leak, it is probably unrelated to the driver retraction problem. There is a trigger valve assembly available to repair that problem (part #A08368, $28.40).

In the case of the FN250A you're in luck though, because the overhaul kit contains both the bumper and the trigger valve for $34.95 which is definitely what I'd recommend. The driver maintenance kit only contains the driver, compression ring, and bumper. Here's a link to the overhaul kit for your nailer:

Porter-Cable FN250A Overhaul Kit

I hope this helps!

Thanks Mike for clarifying what the different kits contain, thats what I was unsure of. I look forward to "This old dog, learning a new trick." Thanks again

Mike, your post of sometime back about the FN250A was extremely helpful to me . I ordered and received the overhaul kit. However there is no cylinder bumper in it. Should there be?
Thanks.

[QUOTE=Mike;2226]Welcome bulletpusher. Usually the piston bumper is to blame when your driver isn't retracting, and since yours is shattered it's a good bet that replacing it will fix your problem (part #886122, $20.67). As for the trigger valve leak, it is probably unrelated to the driver retraction problem. There is a trigger valve assembly available to repair that problem (part #A08368, $28.40).

In the case of the FN250A you're in luck though, because the overhaul kit contains both the bumper and the trigger valve for $34.95 which is definitely what I'd recommend. The driver maintenance kit only contains the driver, compression ring, and bumper. Here's a link to the overhaul kit for your nailer:

Porter-Cable FN250A Overhaul Kit

I hope this helps!"

Mike, I was in error. The overhaul kit did have the bumber in it.
The plastic piston stop was shattered and I have ordered separately the piston stop.
Again, thanks for the excellent post.

[QUOTE=Moon;2873]Mike, your post of sometime back about the FN250A was extremely helpful to me . I ordered and received the overhaul kit. However there is no cylinder bumper in it. Should there be?
Thanks."

Mike, in doing the re-assembly, does the check seal slide over the cylinder? If so, where should it rest on the outside of the cylinder? When the cylinder is inserted, the seal gets pushed up as the cylinder is seated, but I'm afraid it may be blocking the holes in the cylinder. Thanks.

Hey Bulletpusher,
The check seal actually is supposed to cover the holes on the outside of the cylinder..[it helps diffuse the exhaust air..] the lip goes toward the top and the whole seal fits it the slot with the holes..make sure you install the cylinder spacer first and then slide the check seal up from the bottom of the cylinder and then reinsert the whole she-bang back into the tool..:)
Hope this helps..!
Craig

I'm going to bring this thread back, I have an FN250A that the driver is not retracting. I have replaced the driver, and both bumpers. Still won't retract. Any ideas?

Hey BILLS2009,
Try a little air tool oil on the o-rings..also try plugging in the air with the safety depressed and trigger engaged..[to 'reset' it]..You may have a o- ring or trigger problem..the best thing to do in this case is to install an overhaul kit..# 60075
it has all the o-rings and trigger assy..
hope this helps..?
cmoorejack

I am new to this but sure could use some clarification. I received a Porter Cable FN250A for repairs (driver not returning). When I took the tool apart I found the bumper facing cone down towards the nose. I do not have a ton of P/C experience but I believe the cone is supposed to face up towards the driver.
Any clarification would help?

Hey Jason2,
It is supposed to face up..sorry for the late response..hopefully you got your gun back up and going..:)
cmoorejack

Bumping this old thread to keep all the relevant info in the same place.

My wife picked up a used FN250A for me, however it appears have a blown ring or seal. When firing, there is no pressure built up

I have read there are several overhaul kits, but I need to know what exactly is wrong before I can replace parts. I am sure I can figure all this out with a good dis-assembly diagram.

Thanks

Hello, I'm trying to figure out why my fn250 (after a complete overhaul) still leaks air somewhere around the trigger. It works ok but it's driving me crazy. Thanks, Mumford

[QUOTE=cmoorejack;4244]Hey Jason2,
It is supposed to face up..sorry for the late response..hopefully you got your gun back up and going..:)
cmoorejack"

Hey cmoorejack, I think it's really cool that ur willing to give of ur expertise. I go to so many of these forums or help sites where so many people only do it for a buck. Ur alrite,
pforporter ;) P.S. I to was putting a new piston stop, in my FN250A and had not seen where the check ring was when i pulled it apart. I wondered about where u said, but the way the diagram was laid out it wasen't very clear, thanks for that.

ok read the threads ogf 2009 . so let me get this right when the drive rod doesn't return . it is because of the bumper seal ... well my rod doesn't return ... i have good pressure .i pulled the head off and the bumper seal was just fine .... small end of cone of bumper was facing down for the seal top fit around valve on the head. when i press the trigger some air comes out but not near when it was working .... what's going on ?
hadn't used it in a while and u said usually bumper seal at fault..... any ideas of my problem.....

Note to all of you having trouble with the upper piston bumper "shattering". The wrong lubricant will do this. The part in question is nylon - which is an excellent choice for this application, as long as you don't expose it to aliphatic or chlorinated hydrocarbon solvents. If you do, it's toast. That's not the tool's fault. That's user error. Use only the proper air tool oil, The proper air tool oil is NOT WD-40, Marvel Mystery oil, and especially not spray cans of anything, like carb or brake cleaner, ( I know, but you'd be amazed at what folks spray in their air tools, thinking they are "helping it work better".) Also, I'd avoid the cheap Chinese oil from Harbor Freight. Just buy the right stuff. It only takes 2 or 3 drops every use.