Painting - Rubberset Airless Sprayer

I'm posting for a friend who was given a Rubberset Big Shot airless paint sprayer. Motor runs fine but even with the hose off nothing come out no pickup. No air bubbles when you go to prime. I tried to find a manual at Rubberset but couldn't. I rally know nothing about airless sprayers, just acting as the middle man. This is the sort on a stand that sets over a five gallon bucket, My friend would appreciate any help you can give him to get it working. Thanks in advance.

I've never heard of that brand. Assuming that it has a piston pump, it may need repacking. Has he removed and checked the filter?

btw - when it's running right, you don't want to pump paint [or thinner] without the spray line connected.

Has he removed and checked the filter? There is something in the pickup line connector that looks like it could be a filter, round and about a half inch diameter, but it is stuck in pretty good. Could that be it? Just so I can explain to him why don't you run it without the hose?

Most airless sprayers have 3 filters. The 1st one is on the pickup tube. It mostly just prevents the big 'goobers' from being sucked up. Then you have a manifold filter. It's near where the paint comes out of the pump. It's probably contained in a long cylinder looking piece. The 3rd filter is located in the gun handle.

If you could post a pic of the front and side of the pump, I might be able to help better. Airless pumps put out a lot of pressure and with no way to direct the material - it could shoot a long way from the pump making a big mess :eek:

Thank you marksr for your replies. I'll pass them on. May be a few days before I get info back from him.

OK he pulled the block the pickup and return tubes are on and it appears to be a diaphragm not a piston. The diaphragm looks good. It consists of a square of flexible plastic . To the back of the plastic is fastened a circular piece of plastic about a quarter inch thick that fits in a machined well. Extending perpendicular from ithe plastic piece up into the pump housing is a short shaft with a spring. Any ideas on getting this pumping or is it a lost cause.

One question what is the oil inside the pump housing?

I don't really know anything about the diaphram pumps..... only that a piston pump is better. How much oil is in the pump?

On a piston pump you use an oil called 'throat seal' [different brands may use another name but the paint store knows what it is] There is a little reservoir at the front above the the pick up tube where you place the throat seal. It lubricates the piston. It's a special oil formulated so that it won't mix with the paint. I don't know if a diaphram pump uses throat seal.

Since you didn't have any luck locating a manual for that pump, you might try a manual for another diaphram pump - I would think the mechanics would be similiar.

Thanks for your answers so far. Will be back in a few days.