Diana 34 tuning

[mtsheron70]

So I have some time to begin a customers rifle today and open up their Diana model 34 in .177 caliber.  They have only had this gun just over a month from PA.  I am getting ready to do a full tune service and want to get a start of wiping all parts down and doing a chemical clean rinse of the parts in preparation of deburring and polishing prior to the the tune kit arriving.

I inspect all parts and all is great.  Well until I get to the piston!  Look at the picture and tell me if this looks like a stress fracture from the crimping process to hold in the piston post.

In all my days of working on a model 34 or any Diana I have never seen this or noticed it might I say.  This was pretty obvious.

Your 2 cents is appreciated.

[palonej]

Wow Mike!!
I had a major piston issue with my 56 and the first thing Umarex asked was what weight pellets I was shooting. They said light weight pellets can do that. Did you ask the owner which pellets he was using??
In the past year I have heard of around 5 piston failures with RWS.

[mtsheron70]

Wow Mike!!
I had a major piston issue with my 56 and the first thing Umarex asked was what weight pellets I was shooting. They said light weight pellets can do that. Did you ask the owner which pellets he was using??
In the past year I have heard of around 5 piston failures with RWS.

Joe.....do you know if Umarex replaced these pistons for the customer without having to send back the whole rifle?

And thanks for the information.  Not sure what weight they are shooting.  Prior to his buying the rifle I advised them to use a mid weight pellet as a starting point for shooting and zeroing in.

[mtsheron70]

Remembered I had pellets from him to also chrony test his rifle.  They weighed in at 8.2 grains.  Not sure the brand but they are domed.

[mtsheron70]

Went on PA site and narrowed search and they look alot like the Air Venturi Pellets, .177 Cal, 8.18 Grains to a tee!

[jfrey]

Mike,
I had a piston problem with my Air Hawk. The crimps "loosened" and weren't holding the piston center shaft tightly.  Umarex wanted me to send the entire rifle back to them.  The rep actually started asking me if I had taken the rifle apart (obviously I had) and started mentioning things that would void the warranty, like taking the gun apart.    Turns out the rifle was just over a year old so I decided not to send it back to Umarex.  If it wasn't a covered repair they wanted something like $80 for a new piston and shipping back to me.  for a $100 rifle?  Didn't seem worth it so I ended up fixing it myself.   Drilled a well hole at each crimp and had a welder drop in a bead.    Sorry for the long response to your question,  no, they would not send me a replacement piston.     Do however call Umarex.  Your picture is worth a thousand words.  That and the purchase receipt may get you a new piston in the mail. 

[mtsheron70]

Mike,
I had a piston problem with my Air Hawk. The crimps "loosened" and weren't holding the piston center shaft tightly.  Umarex wanted me to send the entire rifle back to them.  The rep actually started asking me if I had taken the rifle apart (obviously I had) and started mentioning things that would void the warranty, like taking the gun apart.    Turns out the rifle was just over a year old so I decided not to send it back to Umarex.  If it wasn't a covered repair they wanted something like $80 for a new piston and shipping back to me.  for a $100 rifle?  Didn't seem worth it so I ended up fixing it myself.   Drilled a well hole at each crimp and had a welder drop in a bead.    Sorry for the long response to your question,  no, they would not send me a replacement piston.     Do however call Umarex.  Your picture is worth a thousand words.  That and the purchase receipt may get you a new piston in the mail.

I would hope they would not make my customer send back the whole rifle for just a obvious piston defect.  But then again they can be hard to deal with I hear.  My other thing would be you would never had known unless this was disassembled.  My question to Umarex is why would one send back a gun to get a piston seal replaced when it is a easy task???  They have to know or understand that is not economical on their part as well.

But hey, preaching to fellow air gunners now who know that.  I hope Umarex does not give him a hard time on this.  Thanks for your reply.

[Nod]

I just took a look @ Airgun Station that has parts for the RWS line and the piston for the D34 has the same indents on it. I'm not sure, but I seem to recall those on my .22 when I tuned it. It looks like some of the models have this and others don't. I have no idea why.


Sorry, I misread what you were pointing out, didn't see the crack.

[mtsheron70]

I just took a look @ Airgun Station that has parts for the RWS line and the piston for the D34 has the same indents on it. I'm not sure, but I seem to recall those on my .22 when I tuned it. It looks like some of the models have this and others don't. I have no idea why.

Hello Nod.  Yes the indents are normal.  The hairline crack however is not.  The indents hold this particular pistons post in place. 

[palonej]

Mike, I didn't have to send the rifle in. I sent a GTA link explaining the problem. They sent a piston for free, but it was marked $56 on the receipt.
I'll PM you the address of the guy I dealt with. He was a gentleman.

[mtsheron70]

Mike, I didn't have to send the rifle in. I sent a GTA link explaining the problem. They sent a piston for free, but it was marked $56 on the receipt.
I'll PM you the address of the guy I dealt with. He was a gentleman.

Thanks Joe!  You are the man!!!

[mtsheron70]

Good news.........PA is shipping him a new rifle then return shipping on the one with a bad piston!  Kudos to PA once again!

[palonej]

Best customer service by far!!

[OleTomCat]

Glad they are replacing it for him, I was going to suggest TIG it up and don't worry about it any more.....

[mtsheron70]

Best customer service by far!!

Certainly is!