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Support Equipment For PCP/HPA/CO2 and springers ,rams => Support Equipment For PCP/HPA/CO2 => Topic started by: SpiralGroove on July 28, 2015, 09:47:17 PM

Title: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 28, 2015, 09:47:17 PM
Hey Guys,
I hate to cry Uncle, but I need help!

Trying to get that last brass nut unscrewed :P, so that I can get at the #007 o-ring.
Anyway, put the the steel (polished) inner tube in a padded vise and finally getting the aproximately 25mm brass nut to turn.  However, it's not unscrewing like it should, just turning ???.  The steel tube in vise Not turning either.  None of the videos I have seen show this.  When you turn a threaded nut, it unscrews - Right?  We'll, not this one.  Also, the other end of the tube w/check valve turning with 25mm brass nut? 
Now, I don't want to scratch anything as it's highly polished, but getting perturbed :o

Help ...................................  :o Kirk :o
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: robertr on July 28, 2015, 10:24:40 PM
 You need to put a crescent wrench on both ends to break the threads loose, the end with the check valve is threaded into the inner tube, the brass end is held in with an o-ring. That is why it just spins.
Have you seen this video?

https://www.youtube.com/watch?v=FEIVWBbfPhc (https://www.youtube.com/watch?v=FEIVWBbfPhc)
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 28, 2015, 10:30:14 PM
OK, Got inner steel tube out, but it's still attached to the 25mm brass nut.  Can't get at the #007 o-ring.
Put the smaller steel tube in the lathe chuck, clamped down very tight, still can't break loose the nut - must be corroded on.  Now stripping steel tube with chuck jaws .......... WAPOS.

What kind of penetrating oil/solvent will work on a brass/steel connection?

Kirk
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: Roadworthy on July 28, 2015, 10:39:43 PM
If you can get a socket on it you could try an impact wrench.  They will frequently break things loose where force won't.
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: robertr on July 28, 2015, 10:51:48 PM
 Have a picture? Not sure which step you are on.
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 28, 2015, 11:05:00 PM
Hey Guys,
As you can see, the steel inner tube came out of the end w/check valve.  So still trying to get that brass bottom nut off so that I can get to the #007 o-ring.  Need to break loose using some kind of solvent.

(http://i113.photobucket.com/albums/n227/kirk_schwarz/Pump%20007_zpsx9cknank.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/Pump%20007_zpsx9cknank.jpg.html)

(http://i113.photobucket.com/albums/n227/kirk_schwarz/Pump%20008_zpsyz07skre.jpg) (http://s113.photobucket.com/user/kirk_schwarz/media/Pump%20008_zpsyz07skre.jpg.html)

As Laurel would say "Another fine mess - Kirk"  :o

Title: Re: Benjamin Pump Repair -> Problem !!
Post by: Night_Raider_ on July 28, 2015, 11:08:15 PM
And WD-40 won't work?
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 28, 2015, 11:09:54 PM
Got it ;D
Because I can be pretty dense at times, I didn't realize that it just slides out the other end.
What a Bone Head :P
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: robertr on July 28, 2015, 11:14:34 PM
 Good job, happens to us all
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: Night_Raider_ on July 28, 2015, 11:17:33 PM
As is the custom around my household for this type of situation, I am obligated to give you a "good job" :D. Don't worry, I've long since given up counting the number of times I've recieved such a compliment ;)

Ah, Robert beat me to it :D
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: robertr on July 28, 2015, 11:28:57 PM
 Looks like I gave you instructions for the wrong pump. :o
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 28, 2015, 11:53:24 PM
Thanks Guys :D
I sprayed the brass nut/steel tube connection with WD-40, will let it sit overnight.  Hopefully, I can break it loose & clean in the morning.  Want to clean all innards real good, then never let it go this long between rebuilds.
I noticed rust/corrosion on the top of the larger inner tube too, so need to give it a good > scrubbing & lube.

Was able to fix my pump gauge ;), the needle just popped off.
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: Case Stuffer on July 29, 2015, 12:54:20 PM
U Tube video  which seems very good to  me.

https://www.youtube.com/watch?v=qnN6NjxSfUk (https://www.youtube.com/watch?v=qnN6NjxSfUk)                         
Title: Re: Benjamin Pump Repair -> Problem !!
Post by: SpiralGroove on July 29, 2015, 02:37:38 PM
Final solution: Heat the brass end with a blow torch for about a minute.  Because of the differences in thermal expansion between steel and brass, it came loose ...... slowly (it squeaked).  The steel thread was rusted pretty good.
Melted a few o-rings in the process, but that's OK.

Kirk