Author Topic: Help with MRodAir MKII Airmax Extreme compressor rebuild. (Read 3051 times))

avator · « **on:** June 30, 2019, 12:15:24 PM »

First a little history of the incident....
I was topping off a 4500 psi 30 minute SCBA tank. I stupidly had a male to male coupler connecting 2 female QD hoses together... I should have known better..
At about 4k the coupler let loose. The compressor and tank rapidly lost pressure. I went for the off switch on the compressor first then shut the valve off on the tank while avoiding the twin metal rattlesnake hose whips that where trying to end my life.
Next I eliminated the need for the coupler and reconnected the compressor.
The compressor would only build 2k of pressure.
Soon after I picked up a Vevor compressor and have been using that ever since to fill guns directly.
Another member sent me a care package of seals, burst discs, o rings and other repair items.
Today I decided to dig in.

avator · « **Reply #1 on:** June 30, 2019, 12:21:35 PM »

Cleared my in house workbench off and gathered up the needed tools. I took the covers off the compressor, pulled out the temp sensing probe and removed the SS air tubes between the low and high side and the high side to the bleed/fill block.
Next I removed the 'head' shown in the picture below...

avator · « **Reply #2 on:** June 30, 2019, 12:26:10 PM »

You'll see in the next picture that I removed the water jacket from the "upper piston jug" (for lack of a better term).

avator · « **Reply #3 on:** June 30, 2019, 12:29:53 PM »

A closer look at what I found on top of the 'small piston shaft' and directly under the head... looks like it was some kind of 'check valve disc' and broken in three pieces.
This item was not included in the 'care package'.
Any idea what it is, where i can get one and how does it go in?

avator · « **Reply #4 on:** June 30, 2019, 12:31:32 PM »

It's made of some sort of metal and appears to have had a hole in the center. It also appears to have been centered over the hole in the upper "jug".

avator · « **Reply #5 on:** June 30, 2019, 12:55:11 PM »

Is this possibly what I'm looking at?

https://www.pyramydair.com/product/av-nomad-compressor-valve-plate?a=8592

avator · « **Reply #6 on:** June 30, 2019, 01:00:20 PM »

At $17 shipped, I ordered one.

Wayne52 · « **Reply #7 on:** June 30, 2019, 01:06:01 PM »

Bill have you ever managed to run down an exploded view/parts list of the MKII ? That would be something very handy to have in English to help identify stuff. You could get stuff like that on request when SPA was still giving info like that to the little guy. Last time I requested something like that they said they didn't have one for a particular model that I requested yet. That was about a year ago but they did reply promptly.

avator · « **Reply #8 on:** June 30, 2019, 01:18:43 PM »

I've looked for breakdowns and youtube vids on the MKII... no luck. If someone does know where I can get a parts diagram or can point me to a repair you tube.. that would be GREAT !!!

I have a good feeling that this is the part I need.

avator · « **Reply #9 on:** June 30, 2019, 01:39:38 PM »

Well lookie here.... a youtube vid on my compressor.... and look who it is.
He mentions the 'poppet' but don't show a picture of it.
Not much help here.

avator · « **Reply #10 on:** June 30, 2019, 02:41:06 PM »

Ok, that part at 6:15 where he says "just wiggle it a bit"... I call BS... I'm still working at it... had to take a break.

avator · « **Reply #11 on:** June 30, 2019, 03:54:47 PM »

WOW !!! That was a bear ! With a bit of coaxing with a rubber mallet while gently squeezing with some needle nose I got it. I just hope those seals survived. I did install new ones.
I inspected the rings on the large piston. I'm satisfied that those are in good shape.
Now to just wait for that replacement disc.

Killfire · « **Reply #12 on:** July 01, 2019, 10:47:32 AM »

Thank you for the pictures of your teardown Bill. They should come in handy when/if mine breaks down. Let us know if that disk for the nomad works. I dont think I have any of those disks lying around.

avator · « **Reply #13 on:** July 01, 2019, 02:19:49 PM »

I sure wish the the distributor that I got this compressor were more customer friendly. I would like to know where to get parts from China for this specific model. I know he sold mostly SPA products but I don't know if they made this compressor.

avator · « **Reply #14 on:** February 21, 2023, 12:28:42 PM »

I'm going to bring this thread back to life because after a couple years of use the compressor failed again. It has been sitting idle for more than a year and, since retired, I've found the time to 'tinker' with it.

A little of the back story as mentioned in other more current threads....

I put the compressor up on the bench with the intention of ripping into it. But something told me to hook it up and run it to re familiarize myself with the issue. Surprisingly, the compressor fire up and built pressure. The auto shut off worked flawlessly and temps were as normal. I ran it several times (with a dead head in the hose whip) to 3k and again at 4k.
It ran great. So I decided to put it into service with thee Gauntlet .177.
On the third time topping off the Gauntlet it suddenly began struggling to get to 3k.

avator · « **Reply #15 on:** February 21, 2023, 12:34:35 PM »

This morning I decided to rip it open and have a look see.
But first, I thought I would reach out to Mike at MRodAir.
Again, I was totally surprised when he answered on the second of his cell phone.
"Mike? Is this you?" "Yep, it's me."
He remembered me and after the exchange of pleasantries we got to the meat.
He told me he had every single nut, bolt, seal, oring and part for my compressor on hand... whatever I needed.
He offered to send me the suspect seal kit and I quickly accepted by texting my address.

avator · « **Reply #16 on:** February 21, 2023, 12:41:32 PM »

While Betty Lou was preparing breakfast (bless her heart

) I slipped down to the mancave where the MKII awaited me on the bench.
I took the hi side head, water jacket and upper cylinder off. The 4 fiber ring seals look ok but most likely worn, as Mike confirmed was the most common failure point. And I will wait for the mail to replace them.
The check ball just before the line from the hi side to the outlet (hose whip and bleed body) is good because once pressure is built and the motor is off, there is no leakage (blow back into the cylinder).

avator · « **Reply #17 on:** February 21, 2023, 12:46:56 PM »

Next I drained the oil and pull the side cover off the lower crank case. The oil was a dark translucent but not burned and had no burned smell.
I have AV HPA compressor oil on hand.. enough for 2 changes so I will put new oil in it.
I wiped the case clean and inspected everything. Nothing was broken and I could see no signs of extensive wear. No metal in the oil.

Breakfast break...

avator · « **Reply #18 on:** February 21, 2023, 12:56:45 PM »

I'm going to pull the lower piston jug off the hi side while I'm in there and change those seal rings as well... those are green orings and I have them on hand.
The most difficult part is getting the top cylinder back on past those 4 fiber rings... it's a wiggle push, wiggle push rinse and repeat process. All the while keeping the splits in opposite alignment. It may not be real important because the splits close up once the cylinder is on but, I like to do it that way with split rings.

avator · « **Reply #19 on:** February 21, 2023, 12:59:58 PM »

Oh yeah... I'm going to change the air inlet filter on the low side as well... I also have one of those on hand.

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Help with MRodAir MKII Airmax Extreme compressor rebuild.

Author Topic: Help with MRodAir MKII Airmax Extreme compressor rebuild. (Read 3051 times))