Hello,
I own a Graco XR-7 airless and am having problems with it. It takes forever to build up pressure, then after I spray about 6 feet it is dead. Then the pump cycles for about 45 seconds and I can spray another 6 feet. I checked the pump filter and it was ok, other than that I have no ideas. I have a feeling that the pump housing might be cracked ( froze with fluid in it over the winter or something) I know I should store it with something besides water or paint in it, but I may have. I thought that maybe there could be some O-rings or something that would cause me to lose pressure. Anyway if there are any airless mechainics out there I would sure appreciate any advice. Thanks in advance.
Cole
Cole Dean
Dean Contracting
Replies
It sounds like your check valves are junked up, if not the whole machine. This is pretty common when the machine isn't cleaned out well or you leave a waterbased product sitting in them. Sometimes you can tap them with a hammer to get them to prime, but yours primes, it just won't build pressure. You would see a leak out from the prime valve, so the sprayer has to be crudded up.
Down and dirty to get it running you can pull off the inlet valve housing and clean up the ball and seat, but you should take it to a shop to be cleaned out and inspected.
By the way, you should always run diesel thru it when it is going to sit. Leaving water and such in it will pit all of these very expensive parts.
Was curious about the "running diesel" part, Im going to assume your being serious, my question is there any other cleaner you can use besides?
COLEDEAN,
I have a Campbell-Hausfeld .36gpm airless. I loaned it to a friend a couple years back, explaining how to clean it and such, and disregarded a thorough cleaning when it was returned. I went to use it a while after it was returned and experienced the same problems you described, builds pressure then when spraying loss of pressure and no consistency. In short, I wound up dropping a wad of cash to fix it. New diaphragm, pressure switch, valve assemblies, basically everything but the pump block. Also bought a new Graco gun(man is that a huge improvement). After replacing all those parts, the machine worked great. I have heard the diesel fuel reccomendation, haven't tried it yet. Depending on how much you use the sprayer, it may not be a bad idea to tear the thing down when not in use for extended periods and clean it well, dry everything, and avoid having to put a lot of money into repairs. I'm not too familiar with any other machines except my C-H, so I may be a little off on recommending tearing the machine down to clean it, that's just what I do. Hope my 2 cents helps.
Qtrmeg and MRROCKWELL,
Thanks for the info. I had hoped it wasn't too serious. I probably have shot about 150 gallons of paint through this sprayer and was hoping I hadn't screwed it up. I will probably tear it down in the morning and see if I can notice any problems, but I doubt I can see them. I will clean it thoughrougly and see if it helps. BTW, when you say to run diesel through it, should I leave the diesel fuel in the pump and hose when I store it? For some reason I wasn't sure if I needed to get it completely dry or leave something in it. Besides paint or water or whatever the hell else I spray.
Thanks a bunch.
Clueless and airless ( for the time being )
Cole
Cole Dean
Dean Contracting
I think you will see what is going wrong. It only takes a spec to prevent the valves from seating. Might as well clean up the prime valve while you are at it.
Clean it with lacquer thinner, and don't sand or scrape anything. Be careful soaking any plastic parts in lac thinner, I doubt they made this thing with the best technology.
Flush it with diesel, and release the pressure.
Thanks for the help. I know she's a real low end unit, but I don't spray that much so I would like to use it as long as possible. I'll see what I can find.
ColeCole Dean
Dean Contracting
Diesel or Kerosene. Both are a close relation in the fuel spectrum. To flush those our prior to painting use some paint thinner. Diesel and k-1 are oily, they wont be noticed much on oil based paints but they might cause some grief with water based if you dont flush it out some.
As someone mentioned Laquer thinner contains a myriad of solvents. One of them is acetone, it likes to eat plastics and some rubbers.
I would bet that his machine should be taken apart and cleaned, but it also needs to be inspected by someone that knows what they are doing to determine what (if any) parts need to be replaced. And it would help if you don't damage anything by cleaning or assembling.
Both of the machines you guys are talking about are toys, and have toy parts. They also have borderline output, so you have to maintain them very well. Best advice? Flush them well when you are done, as soon as you are done, (make sure you flush the prime circuit too). When they flush clean run diesel thru them. Seems to me it is better to have metal sit in a bath of oil than sit dry.
Um ya, now where might you have heard about using diesel, like from every sprayer mechanic?
Good advice Qtrmeg,
I knew when i bought my sprayer that it was a toy, but for as much as I use it, it's been justified. As far as diesel goes, didn't you know that diesel is the wonder fluid.LOL Great for removing tar off the truck, and some guys I know use it as a blade lube for their Woodmizer's, not to mention as aftershave.LOL I have a dodge/Cummins and am a bit of a diesel nut. Man I love the smell of diesel in the morning. Sorry to go off topic, it was the diesel talking.
Hey, I bet my toy is bigger than your toy, but it is still a toy. I have a Titan 880, biggest pos I could find when I needed one.
Don't get me started on diesels, paint it yellow and put a bucket on it and try to keep me away. I don't know about the diesel aftershave, but I have had a hydraulic bodywash or two.
As for tar on the truck, I just buy black trucks.
Go ahead and go off topic, all this paint related talk freaks me out.
To clean flush with a solvent for the product you are spraying. Water for latex, thinner for oil, etc. You can leave thinner in the machine, but never any water, (ya ya, they have additives for water...). Diesel flushes the water out well and being an oil it keeps the machine lubed, plus it is cheaper than thinner.
One cleaner you may want to stay away from is lacquer thinner. Bunch of reasons, one being static in the lines, some sprayers have issues with seals, and it will free up any residue to go and clog up everything in sight.
Thanks, I do not do much spraying but I guy I work with does, usually uses lacquer thinner to clean out the machine after spraying lacquer, I don't know what he keeps in it after that, but was looking for some advice to give him since he just spent 1500 on a new machine,
You think diesel is the way to go?
"You think diesel is the way to go?"
What, do I stutter?