I rebuilt my 40 year old Benjamin 342 this weekend. It was originally my Brother's, now passed away. The seals had long since expired and ot would barely hold pressure. I know he had used 3 in 1 machine oil to lube it and that likely had killed the seals. I ordered a seal kit and a replacement trigger guard on EBay from Palmer's Pursuit Shop-he had it all including the crucial valve removal and installation tool.
With a little time spent on cleanup and getting organized I had perhaps three hours invested. The gun had a lot of grease that needed to be cleaned out of the pump chamber and valve chambers. That took some scrubbing with detergent and a 12 guage shotgun swab. Afterwards I blew it out with air and then swabbed with cleaning patches to make sure it was dry.
The tougest part of the project was getting the front checkvalve ito drop in the right direction with the rubber face towards front. Also getting the valve stack back in with the two solder washers against the spring pressure of the two springs was a little tricky. It took perhaps ten trys but eventually things dropped into place and tightened up.
Now, six pumps will yield around 680fps and groups around an inch with the open sights that came on the rifle. That is the best my eyes can accomplish. It was very gratifying to see this old classic work like new again!
This was not a difficult project and Inwould encourage anyone that has one of these great old pumpers on need of repairs to give it a try.
