low press wax spitting

[diamond joe]

I have a five bay self serve with D&H equipment.There are three low pressure functions on one circut,pre soak,wheel cleaner and wax.Each function has its own low pressure pump and the air is shared by a manifold with solenoid valves. My problem is that the wax function only works properly in one of the five bays, in the other four it spits and seems to run out of chemical sporaticaly. To date I have checked the following;free flow of chem to the pump...pump output is 60psi....checked all solenoid valves on chem and air manifolds...air press is set at 40psi as always...all connections at the sub manifolds in the attic. Im running out of things to check! The only way to get the wax to dispense smoothly is to lower the air press to about 20psi at which point its realy running off the pump alone.

 

[MEP001]

I'd say it might be the wax, or the need for a foamier one, but if it works without sputtering in one bay that's probably not it.

Are these block solenoids, and are there needle adjustments? They could be closed too much on 4 of the 5 bays.

Is the one working bay the closest with the shortest run of tubing? There may be line loss to the farther bays and they aren't getting enough liquid.

 

[Jeff_L]

I know you said you checked all the solenoid valves, but did you check the plunger inside the valve to make sure it hasn't expanded to the point to restrict the flow? The little rubber nipple on the bottom of the plunger either needs to be cut or replaced over time.

 

[captain cw]

If you have foaming chambers, I would check those and make sure they are not clogged.

 

[galen]

I would say that the air is set too high. To work properly you my need to put an air regulator on each of the liquid products. The fine tune each to it's own characteristics. I have found, no matter which chemical I use, to get a good display in the bay, I set the product pump pressure at what I want to flow with all the bays running at the same time. Then equal that pressure with the air or just a little below that. Product=35 lbs. Air=35-32 lbs. That way they mix well at the gun. Needle vales on each line will fine tune them even more. If you have the air set too high the produce will sputter , because the air is overriding the product. Which ever is greater, that is what you will have the most of at the tip. Remember to pull the trigger when setting pressures. Three different air regulators, needle valves, and slightly lower air pressure on the air side and you will have a great display in the bay or each of the different products.

 

[mac]

Also be suspect of the pressure gauges. Even though the air gauge says 40 psi, it may not be. It's common after a couple of years with the pressure in the same setting for the gauge to get stuck. Run the air pressure up and down and make sure the gauge shows this. Jeff also brought up a good poing. A lot of waxes have a petroleum part that makes the little rubber puck inside the solenoid swell up. It doesn't take much to make a big difference.

 

[MEP001]

The gauge can also get damaged if high-pressure backs up into the solenoids. Make sure there's no pressure on the block, and the gauge should read zero - replace it in it doesn't.