Question about Porter Cable Cable BN125A Factory - Reconditioned 18 Ga., 1 1/4" Brad Nailer Kit

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Porter Cable BN125A won't set nails below surface

I have adjusted the depth gauge, but nailer still leaves nail heads exposed about 1/16th inch (regardless of length of brad) ... air pressure settings between 60-100 psi have been used, but same results.  Do I have a bad seal somewhere in the unit?

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You might check the end of the driver...they have been known to chip off.

Posted on Jul 27, 2009

  • Jw Raabe
    Jw Raabe Mar 09, 2012

    try a 3/8 air hose the smaller ones don't work not enough pressure going threw it

  • Sid Newton May 04, 2012

    I had the same problem. I found out the linkage for the depth control was not assembled correctly. First, of course, remove the brads and disconnect from the air supply. Open the front like you had a jammed brad, pull out the bottom part of the linkage a little (it goes all the way to the nose. Adjust the depth control until you can see the slot in the top section of linkage. Slide the bottom section of linkage back in place so the little knob on the top part of it slides into the little slot on the top part of the linkage. Then swing the front back into place and latch it. If it takes 5 minutes, you're doing it wrong. Good Luck.


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Not sure about the seal, but I do know the pressure has to stay up for this nailer to be effective. Try oiling the gun to free up the mechanics and don't use old nails.

Posted on Jan 25, 2009

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Assuming that the nail head not setting in and adjusting depth control does not remedy. Usually occurs when the tip breaks off. Remove the head and pull out the driver to examine tip. If tip broken or bent, replace with new or try to adjust as needed. If about 1/16 of tip broken, reshape the driver so that the tip is just slightly wider than nail head, taper the lower 1/4 inch on the side of the driver that faces the nails so that the driver will only strike one nail and reduce (shave) the size of the lower bumper so that the driver will extend out same amount that you need due to broken tip(only works if 1/16 -1/8 broke off).

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Could be very simple problem of headvalve oring coming off or pinched. Remove the head and look at the oring installed on the headvale. Sometimes this oring will fall off the grove. If the oring is off groove and is pinched, you may need to replace with generic oring sold at Lowes (if oring is gold vinyl replace with black rubber from lowes, will work better). If oring is in place, pull out the cylinder and examine the driver for bent blade/broken. If bent, make adjustment or replace as needed. If the driver is in good shape check that the check valve is in the proper place. The check valve is a black rubber band around a series of holes on the outside of the cylinder. Good luck

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The depth to which a fastener is driven is controlled by the depth adjustment

knob (A) Fig. 19 below. The depth of drive is factory adjusted to a nomimal setting.

Test fire a fastener and check depth. If

a change is desired, rotate the

adjustment knob (A) Fig. 19: the

adjustment knob has detents every 1/4

turn. Rotate the knob clockwise (see

Fig. 19), to increase the depth of drive,

rotate the knob counterclockwise to

decrease the depth of drive. Test fire

another fastener and check depth.

Repeat as necessary to achieve

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Good Luck

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Wrong type nails.

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