Stanley Bostitch CAP60P-OF Compressor Replacement Valve Plate Assembly # AB-9429999

If you have an old CAP2040P Bostitch compressor, everything you read will tell you NOT to buy this AB-9429999 valve plate assembly, because it is only for the newer CAP60P. NOT TRUE!After rebuilding it with this valve plate assembly, my 2006 13-year-old CAP2040P compressor cranked up to 140 PSI in about a minute! There's a lot of advice from some good folks that helped me give this a 5-star rating. Here are some things that will help you be successful...1. First, thanks to L. Entringer for saying you may need to TURN your valve plate 180 degrees (don't flip it over!) There are several reviews that mention it may have been assembled wrong at the factory, but I'm thinking it may also be possible that this valve plate assembly fits other brands of compressor, some of which may have the exhaust coming out the other side, so either way, take his advice and check to see that your intake and exhaust are oriented properly.2. When I took the cylinder head off and realized one of my three reed valves was broken (see pic), I started to figure out what parts I needed. Talking with Bostitch factory folks, I found out there was a type 1 and type 2 CAP2040P compressor, as well as the newer CAP60P. Adding some input from other parts distributors, and sorting thru some inconsistencies in parts diagrams, everything pointed to this valve plate working on my older compressor.3. So I bought this AB-9429999 valve plate assembly at a great Amazon price, and after getting a couple of extra parts and about an hour’s work, my Type 1 CAP2040P compressor is like brand new. Here is some disassembly and assembly advice…a. If you use an impact driver to remove your four cylinder head cap screws, you may vibrate the inner hex nuts out of their slot. If you do, tip the unit backwards and drop the nuts back in the slot as you push the cap screws down and start threading them.b. There are several reviewers who advised replacing the piston arm, and you might as well. I tried several methods to get the top screw out that holds the piston cap to the arm. I eventually took the arm off, and while holding the arm in a vise, the casting snapped where the screw goes as I tried to remove it.c. Even if you're lucky enough to get the top cap screw out, don't use the old piston cap! Use the new one that comes with the kit – it’s VERY different. Upon re-assembly, make sure the screw is in the recessed area of the cap. If you don't, you'll find your piston will not travel all the way up. A way to make sure you have everything together correctly and avoid possible damage is to hand turn the squirrel cage a few times and make sure the piston travels up and down unobstructed.d. If you replace the piston arm, there’s a good YouTube video by Master Tool Repair that shows how to slowly work around the bearing and remove the arm with a screwdriver. When you reassemble it, using a socket to tap it in place, make sure the piston arm is centered in the cylinder. I had to slightly tilt mine so it wasn't rubbing on the walls in order to install the ring with uniform clearance. There is a little looseness in the bearing, so when the piston cap and ring were installed and things began to move, mine repositioned itself.e. If your cylinder walls are fairly smooth, you can wipe down the cylinder sleeve and not need to replace it, but don't put everything back together without AT LEAST replacing your piston ring, or you’ll most likely lose some pressure and not get the ultimate return for your efforts.4. For my rebuild, you can see the old parts in the pic above. Here’s my Parts List:a. AB-9429999 valve plate assembly (includes piston cap & screw) $17b. A610101 piston arm $13 (from eReplacemebt Parts)c. AB-9040019 piston ring $105. That’s it! Hoping I can get another 13 years out of this little guy. Good luck!

First problem. Valve plate comes pre-assembled and wire tied to the new head. Only problem is it's assembled wrong. The valve plate needs to be turned 180-degrees. The picture that comes with the parts show it incorrectly oriented as well. If you put it together and it blows air out the intake port you have it put together the wrong way.Second problem. The new valve plate assembly is preassembled and held together with two roll pins, and sealed with a thin aluminum gasket. Unfortunately the aluminum gasket isn't up to the task. With just four bolts holding it all together and the air pressure developed inside the head, it easily leaks out between the plates.Solution: I took mine apart and coated the aluminum gasket (both sides) with copper spray gasket sealer (available at any auto parts store.) Once re-assembled and allowed overnight to cure, it seams to have sealed nicely.

Well - either I'm more mechanically challenged than I thought or I happened to receive a lemon. My repair efforts have taken me well over a month - between the scanty instructions provided with this unit and my efforts scouring the YouTube videos (helpful, I'll add) offered through other parties. It should be mentioned that this replacement, while being an 'upgrade', is quite different. In fact, I learned that the terminology involved with this purchase converted my unit from a type 1 to a type 2 compressor. Being an average weekend warrior, I feel such a difference needs to be clearly stated.As such, I learned that this conversion necessitates the replacement of the piston cover (included in the kit). This is fine, but its important to note that the process required for this replacement - more than likely - involves a snapped torx screw that holds the old style cover. Because it was virtually impossible to remove the sheared screw, I had to resort to ordering yet more parts - in this case, a piston arm.Then, just when I thought things were just about finished, I realized the parts had been reversed in their assembly order. So, thinking a mere flipping of the valve plate would solve this, I removed the top and made the adjustment. Unfortunately, the compressor continued to blow air out of my intake. I'm at a loss at this point; should've bought a new unit, in light of the bourse of time lost trying to perform a "simple fix" on this one.

Beware part may not be assembled properly - Before I installed the Stanley Bostitch CAP60P-OF Compressor Replacement Valve Plate Assembly I marked the Head and Plates with a sharpie so the assembly would stay in order if I had to take it apart again. After installing the parts I tested the air compressor and to my surprise the air compressor did not fill the tank. I remove the head assembly again and checked the valve plate oreantation and found it was installed wrong, The Vavle Plate was Reversed. After Reversing the valve plate and reassembling the compressor worked as it should. This part was not Assembled Properly from the Factory !

For installation on a Bostitch CAP60P-OF the valve plate needed to be rotated 180 degrees from how it was assembled and shipped. As well the valve plate leaked and would not allow the compressor to come up tothe 135 psi pressure to turn itself off. It needed to be taken apart and have gasket sealant applied.

Wrong size for my compressor

doesn't build enough pressure to shut compressor off 100 lbs max. so it's virtually useless