watertech 24

[watertech24]

I have a softgloss about 10 years old now. Top brush will stay down on small vehicles. I've changed the mac valve, regulator, and air cylinder. may wash 20 or so cars. seems the problem is only on small cars. when I arrive there is air coming out of the bottom of the air manifold assembly. please help.

 

[Stumpy]

Did you resolve this?
I'm having this exact problem and hoping a bump will bring an answer from the aether.
Please!

 

[MGSMN]

Sounds like you covered most everything but also open the needle valve on the air cylinder, this controls the lift speed. I will assume the PLC output relay (Y37) is not sticking on keeping the Mac valve energized and that the main air pressure regulator is set to no less than 110psi. My guess is one of the other Mac valves is bypassing air causing the top brush to not have enough pressure for lift, especially on small cars when its in its farthest down position. I would get another new Mac valve and swap out one valve at a time with the new valve. You may have to move the new valve to many of the other spots on the manifold until you find the bad one. If your machine has wheel scrubs I would start with one of those three valves. I had the air bypassing through the manifold issue and I ended up having to replace two valves before it stopped. Before I got to swapping the mac valves I verified that the side brush arm air cylinders and the wheel scrub air cylinders were not worn out and bypassing air through them back into manifold. All the Mac valves on the manifold are the same except for the "On Board Dry" nozzle oscillate (if you have that option), it is a 4 way valve.

 

[Stumpy]

Thanks for the reply. Although we couldn't recreate the error toggling the outputs, we were lucky that a sedan pulled in and we could cause the failure. Applying a little push to the left rear arm gave the upper brush enough energy to return home.
We changed out the top brush and rear return mac valves and that seemed to do the trick. Im pretty sure it was just the rear return sticking open that drained the air pressure and caused the problem.