AR45 pump repair/service tips

OK starting a thread for everyone so that we can actually have our own good knowledge on these pumps and how to work on them. I recently got one and I’ve already had several issues. The discharge manifold, fittings, O-rings, leaks etc. PLEASE ADD TO THIS LIST! We all need more info than the vendors will tell us.

  1. Get yourself extra parts right off the bat this includes the discharge manifold, might as well get an intake manifold, The fittings which are the part that has the O-rings and go into it. Extra forks because they may break off and disappear. Extra hose barb fittings AND the O-rings because they do not come with the O-rings.

  2. When connecting a fitting (the 2 pieces that have 2 O-rings and connect with the fork into the manifold, Hand tighten until it’s pretty snug with your hand. put it in and see if it leaks. If it leaks give it 1/2 turn more. (DO NOT OVER TIGHTEN!) these cheap plastic pos’s break super easy! most important

  3. Check your oil‘s shortly after using as they may not be nowhere near what they’re supposed to be if buying a new unit.

  4. Put two hose clamps on everything it will leak!

  5. The specs are supposedly 7 pounds of torque but good luck finding a torque wrench to gives you that much accuracy. Leaks are all abundant if it’s not tightened perfectly.

  6. The “non-crushable hose“ can definitely be crushed if stuff sits on it and it gets hot. Keep your hoses routed and safe from intrusion.

  7. The fittings for the pressure gauge and the discharge hose going to the hose reel have different size threads. Make sure you get fittings of each size otherwise you will need an adapter.

  8. There are many different O-ring sizes make sure to get some of each.

  9. Anyone with extra experience on this please add to this post so that we can all survive what everyone thinks is it hot mess! The machine is awesome (when it works) and I’m sorry (not sorry) but the vendors are not very helpful!

  10. Put hose clamps on the forks (big enough to wrap around fork and manifold) that hold the pressure gauge and discharge fitting (hose to reel) in place. They vibrate off and break the plastic!

Who in the heck is running your machine, King Kong? I’ve had mine for 18 months and the only thing I’ve done is replaced one O ring and that was my fault for not letting the pressure off before I shut it down, causing it to hammer. Always start it or shut it down in bypass mode or make sure your gun is on.
Having a maintenance thread not a bad idea though.


Maybe you got a lemon lol. I’ve had my AR45 for over a year now and only had to do regular maintenance. The gauge it came with did eventually start leaking so i took it off and just out a plug in its place. The aluminum skid it came on developed a crack but i welded that. I could not live without my AR, I love it.

If you want to torque it to 7 ft lbs you can get an In-lbs wrench and go to 84 in-lbs.

That’s one thing I’m struggling with. The 7lbs of torque. I got a torque wrench last night and set all the bolts to 8 (it’s increments of 2) and I had a little leak out of the bottom. I had to tighten it to 15-20 (they aren’t that accurate that low). I’m nervous about it being too tight does that seem bad?

@Racer I did not know about being on the trigger when starting and stopping. It makes sense because it usually backfires after shutting down. I used to do that on the Pw but stopped after getting a flow sense unloader.

I got it from Envirospec and they must of been rushing. Didn’t send half the stuff to come with it. If I was a vendor I would include a little checklist sheet with every order that says something like: congratulations on the purchase of your new AR system. Here are some things you should do to make sure that you don’t have a ton of problems right off the bat. Here’s a checklist of everything that should’ve came with it please make sure you got everything. Here are some common parts to have on hand that are probably gonna break. I would rather have purchased one from Georgia airless but they were booked out until the end of July and I could not wait that long.

You don’t have to hold trigger, you can just switch to bypass mode before starting or cutting off Either should work. Engine backfire nothing to do with that.

Where did you get your unit from? i already have a backup cold water unit found, now im searching for the softwash system. Going to keep the delvan on the rig as a backup and my other delvan as a transfer pump for sh

You never want to use a wrench for a torque setting that low. Even 1/4 inch ratchet is overkill. You need what’s called a torque screwdriver with an adaptor for the head you need. Electronic stores will have them. Don’t buy a cheap one get a good one, one throw into the toolbox and it’s out of calibration. Not that you really need surgical accuracy with 7 pounds of torque, nip it up sensibly and your good to go.

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Envirospec. As soon as you use it you will only want the 12v for backup.

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Just ordered this one it will be here tomorrow. Vortex Optics Torque Wrench Mounting Kit, Black Vortex Optics Torque Wrench Mounting Kit, Black: Sports & Outdoors

Looks like the right deal huh? Has a 1/4” adapter which will work with my 1/4 to 3/8 socket adapter to use a 13mm socket on it. It looks like a Great tool man, thank you! I definitely don’t want to mess up my new system and this looks like a key tool have.

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is the pump supported at all? i feel like i could build this myself with their base plate and getting the pump / motor somewhere else. i feel i really dont need the big footprint they made for the tips to mount on or the tips they provide honestly. what do you think




They actually did not have the large skid and gave me a smaller one which is just big enough. I dont want the big one it is a waste of space and you don’t need the stupid fancy connectors to hold your tips that you’re never going to use with their weird lance. The pump is bolted directly to the motor and does not have brackets which is silly because eventually it’s going to want to cause issues I think. They sent me the brackets but there’s 1.25 inches of space between the bottom of the brackets and the top of the skid. I ordered some rubber feet to cram in between so that the pump will not rattle or bounce and put stress on the motor bolts.

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I’m going to build my own.

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