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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: 2L8 on September 17, 2017, 11:53:36 AM

Title: New Maximus…..with leaks solved, and….
Post by: 2L8 on September 17, 2017, 11:53:36 AM
Hey all, Glad to have read some great stories on GTA this summer. As always there is great comradery, fantastic technical data and problem solving solutions shared here. Cheers to all that contributed making this THE GTA!

My new story begins the first week of August, with a look into……..Shhh!….(the dark side), OK, I said it, yea, I looked and was immediately sucked in by “flashy lights” ( weight, accuracy, features, upgrades…..) and a under $200 price tag for a Maximus Hunter .22 w/ 6x40 AO and a 26” barrel LDC ready for $165.00 shipped from Crosman with a 5 shot test target confirmation @10y of a 1 hole group, made this a done deal.
After the party I clean up all the cake and start analyzing what I got here.
 Crosman shipped the retail box INSIDE a shipping box for extra protection from UPS. It worked fairly well as there were a few depressions and dings in the retail box when opened but all is good and intact, no broken bits. Thank you Crosman.
Ordered the usual Chinese hand pump on Ebay that looked like an Air Venturi G4 knock-off (or the real thing) from the colorful descriptions and great price of $53 shipped.

So far I’m a happy camper…..
After reading many “how do I’s” by all of you very knowledgeable GTA gurus, I proceeded to adjust, tweek, tighten and then mount the 6x40. I pumped to 2000k after 105 pumps from “0”psi…..Hmmmm?
Shouldn’t there be SOME pressure in this thing?.......
Shot the first 5 CPUM @ 15y to make sure it hit a target….it did, quite well as a matter of fact, but, louder report than I wanted. The initial engaged release was not bad but it was after the pellet just left the barrel that it “cracked” and made a very audibly higher dB noise that was not “BYF” back yard friendly.
 
A quick email to Rocker1 and a LDC was on its way………Results=fantastic. Crazy quiet!. Thank you Rocker1.
The next 60+ shots @ 20-25yds were above or@ the advertised data for Shot count, FPS and FPE with all groups @ 1/4 “ and less.

I’m a Very happy camper so far….
After a week of bliss and eating leftover cake the party is over one morning when I head out to eliminate some ¼” red dot’s @ 25 yd and the AR just goes “Pfffftaaa”……What?, Re-cock the bolt, aim, pull and ….Pfffftaaa. Look at the gauge and it’s at “0”psi. WTH?

The new journey begins.
In the GTA search bar I type “Why” and it proceeds to spit out more reasons and solutions than I could have imagined. I started with the few I could deal with and positive results presented itself in a couple of areas on/in my rifle.
Using the trusty old “soapy water” test at the threads of all the common areas of the gauge, gauge block and fill valve, I was lucky and found leaks at the connection of the gauge to the air tube and at the Foster connecter end, not the threads.
Called Crosman that day and Chuck said “No problem, I’ll send you a new Foster adapter (1761-101), pressure gauge and adapter (1761-014, 1761A017) with o-ring (1761A023), no charge”. 8 days later I have said parts @ N/C. Thank you Crosman.

In the mean time I read Way more than I should from all you crazy tinkerers that know how to make these AR’s “sing and dance” like no body’s business……

With a week down I have time to at least hone the trigger a bit by getting a couple 4-40x ½” allen’s for a stage 1 adjustment and after release stop point, .023 x 7/32x 5/8” spring (Ace hardware) and polish all the trigger contact points to a mirror, adding a little Moly to make sure all is very slippery too.
 
Cleaned out the air tube of the little grime that was in there with a dowel and then with a piece of T-shirt dabbed with 100% silicone oil on it for good measure. Cleaned the gauge block threads of the leftover gunk from machining and then installed the pressure gauge with Yellow Teflon Gas tape around the adapter 3 times and making sure there was no tape near the seat area of the rubber O-ring. Dabbed a little 100% silicone on the seat area of the gauge adapter and installed. Tighten till it stops, you will know it, it feels right. More cranking is Not better. Wiped a little 100% silicone on the 2 O-rings of the Foster connector and gave it a good snug tighten with my 9/16 deep socket.
Assemble back in the stock. Cocked the bolt to set the check valve and proceeded to pump 100+ stroke to achieve 2000psi.
It has been 15+ hours now and Maximus is holding @ 2000psi!!! Before it would be almost empty by now.

Having learned much about O-rings during this process I will be upgrading all O-rings to Viton V75 for an experiment in the next rebuild and keep you posted on my results.

Time to go shootin’!!
Title: Re: New Maximus…..with leaks solved, and….
Post by: aluminumfetish on September 17, 2017, 12:04:28 PM
It certainly beats golfing !
Keep us posted and be safe !
Title: Re: New Maximus…..with leaks solved, and….
Post by: Mr. Panther on September 17, 2017, 02:12:09 PM
it is one of the first things I did when I got mine was reseal the foster fitting and air gauge. I read a lot about the problems  om here about wha twas happening so I decided to do that right away. been a couple weeks and mine hasn't dropped a lb of air yet. :) Happy shooting.
Title: Re: New Maximus…..with leaks solved, and….
Post by: KnifeMaker on September 17, 2017, 11:41:59 PM
Would like to try Viton "O" Rings.

My fill leaked thru the actual Male fitting. Turns out that there is a tiny "O" in it as well. Have to take it totally apart to find it.

Crosman, did not know it had an "O" ring in there. LOL. They sent me a new full plug, and she has been doing fine ever since. I did replace the tiny "O" ring in the mail fitting several times. I leaned that if you shut off  the fill air quickly, it can shred it.

Now about golf, I love shooting golf balls. (If you have enough fpe for the pellets not come back as fast as you sent them down range) LOL!!!

Never did care for whacking golf balls with a club though.  Everything shooting, is just more fun! ;) ;D

Tried shooting them with the .257 hp, but too much trouble. They just explode. Can't keep enough around to make it worth while. GRRRR!!! 8)

Knife
Title: Re: New Maximus…..with leaks solved, and….
Post by: Tater on September 18, 2017, 05:48:48 AM
Nice job with it Patrick.
Title: Re: New Maximus…..with leaks solved, and….
Post by: Bicycleman on September 18, 2017, 11:03:33 AM
Patrick, I am happy that you were able to find and repair the leak yourself.
I have one of the first Maximus .22s sold and hunted it during the Fall/Winter season.  Toward the end of the winter, I noticed that it had a slow leak.  After the season, I took it down and found two leaks - the first at the gauge and the second at the fill area.  I used it during the Spring season with no problems.  It has been hold pressure since repairs were made.   ;D
Title: Re: New Maximus…..with leaks solved, and….
Post by: 2L8 on September 18, 2017, 11:41:38 PM
As you can imagine I was totally bummed that the QC just wasn't there on the critical internals. Man, just make “X” less rifles a day out of "X" number, take a tad bit more QC time and make a better overall product. The math will work in many ways, trust me.

A great barrel with an unusable trigger is of no advantage, poorly machined internals has your rifle on the Brown truck back to the factory, not a happy camper, and a great trigger with a rifled barrel that can’t find the same hole twice is useless. Not every one of us here is an engineer, machinist, inventor or handyperson with a plethora of tools (Thank you GTA!) and time to repair what should be, at least, a basic working AR that functions as described on the fancy box it comes in. The marketing hype, by far, exceeds the quality output on most all the entry-level to mid-level AR’s.

Crosman, for me, has stepped up to the plate whenever I needed any customer service and/or parts, shipping time is consistent as well as shipping costs, parts are more times than not in stock and they let me work on my AR without voiding my warranty ……….That’s all fine and dandy but I don’t want to play that card Every time I buy an air rifle with their name on it !!!!

Enough rant…..

My Maximus is now giving me 30 clean quality shots from 2K-1k. I didn’t bring my chrono with me this trip to NM but I will report back in Oct.
I will still note that I am very happy with my .22 barrel as it performs with utmost accuracy each and every time I pull the trigger, although, I still plan on the Mrod Gen1 trigger upgrade.

It’s party time with cake again.

Going to try match sticks now @ 25y………..

Title: Re: New Maximus…..with leaks solved, and….
Post by: Mosin Marine on September 18, 2017, 11:57:31 PM
Glad you got it solved!
Title: Re: New Maximus…..with leaks solved, and….
Post by: KnifeMaker on September 19, 2017, 08:59:36 PM
Installed the MRod trigger group and spacer from discos-r-us. Love-it!!! ;)

Knife