Tuning How to safely remove, replace an EDMU

[Mtscott]

I am new to the forum and recently purchased my first PCP, a used Impact X. There is a EDMU on bottom of the rifle I purchased. It appears the EDMU is not working correctly. I can not get the EDMU to light up or indicate a pressure. I want to pull the EDMU, replace the battery and trouble shoot. I found a video on the battery change. I do not know for sure when it is safe to remove the EDMU. Do I need to depressure the rifle? What safety or mechanical items do I need to consider? Any help is humbly accepted. I am still learning the terminology of the parts so if I need to clarify let me know.

 

[mvonbeamer]

I have an EDMU on my Vulcan. I change the battery without removing it from the rifle. There is a good video on line for changing the batteries. It is a pain. 

 

[Mtscott]

mvonbeamer,

I did find the video for battery change. I will try that first. I was trying to figure out how to safely remove the EDMU in case it needs replacement.



Thank you,

Scott

 

[Mtscott]

I changed the battery. Looks like I will need to change the gage. I ordered a analog gage. I assume the gage is safe to remove if the gun is not cocked? Otherwise looks like a simple replacement. If there are any tips or other potential issues I would appreciate any input.

 

[Beach-gunner]

high pressure Air (HPA) is very dangerous. No need to cock the gun, definitely a need to degas ALL air from air tube, serious injury will occur if not degassed. Also get an owner’s manual.

 

[Mtscott]

Beach gunner,

Thanks for the reply. I understand the danger. I have an owners manual. I have read and re-read the manual. Unfortunately the manual does not indicate how to degas all the air from the air tube. I assume the air tube is charged when cocked and depressured when fired. I can't confirm the air tube is degassed because the gage is broken. I was looking for some guidance not available in the manual that came with the rifle.

The gun is old enough to be out of warranty and there are no air rifle shops in my area. I will be doing basic jobs like this myself. 



- Scott

 

[Beach-gunner]

Scott,

The air tube remains pressurized through the shot cycle. The Airtube has a larger volume of air due to its size, all the air from the tube will not dump in 1 shot because of the regulator that is holding the remaining air (that not used in the shot cycle), from entering the space the regulator occupies. This is way you can get multiple shots from a 250 BAR fill of you airtube. Each shot of air is measured by the regulator. Understand if your regulator is set at 130 BAR and you shoot multiple shots from a 250 BAR airtube fill, eventually the airtube pressure will come down to 130 BAR as you deplete a small volume of air from the air tube with each shot. Going below the 130BAR regulator setting while continuing to shot is called falling off the regulator. There still is 130 BAR of air in the air tube...this is approx 1,885.49 PSI.....still very dangerous. This is why air air must be debased from the air tube. In short go here and watch Earnest Rowe’s FX Master class videos.



https://youtu.be/9YqGmKBA728



EDIT: somewhere is his videos you will learn how to degas the FX airtube.

Dennis

 

[Mtscott]

Dennis,

Thanks again. That is the information I was looking for. I will watch the video or videos. 



- Scott



The fx master class videos was exactly what I needed. The first video on disassembly covered depressuring in the first few minutes. I will book mark the video series on YouTube and use them as a reference.

thanks