Randy

[avonlaserwash]

Spot free rinse has small amount of chemical bleed on first half of pass. It leaves little spots on surface of vehicle on hood and driver side then goes clean on the rest of the vehicle. All the check valves are good and don't leak back upon checking them. I have two bays and it only happens on the one bay. It's got me stumped !

 

[MEP001]

The title of your thread is very confusing. Might be helpful to give the make and model of your machine.

 

[soapy]

You should be able to change a setting in the plc to prime the spot free rinse a little sooner or delay the timer to start gantry rolling a little later.

 

[keded]

Type of Equipment

The title of your thread is very confusing. Might be helpful to give the make and model of your machine.

MEP he has 2 bay PDQ Laserwash 4000. I think he's saying he has the same settings on both machines but only one is having the problem

 

[jcollins]

Try putting a "new" check valve for the spot free on the overhead manifold. The check valve on it now may have been only seating when you tested it.
Your distributor has a "new style" 3/4" s/s check valve that is actually less expensive than the Parker check that I think is on your manifold now.

 

[avonlaserwash]

Thanks, This is the first I've done this...I have 2 bay laser 4000's built in 1999. The 3/4 check valve is stainless Parker and seems to holding fine. I can't think of any other place that chemicals can bleed back in from.

 

[Mike]

On a laser 4000 the spot free system is seperate from the chemical lines except where they combine in the overhead manifold. The check valve on the overhead is you most likely failure point.

To test this swap check valves on the bays and see if the problem moves.