Caretaker 99 not switching zones after pressure increase

[silver_bullet]

After turning on my in floor pool cleaning system, it goes through the same five zones with pressure just over 22 PSI. When the valve switches to the 6th zone the pressure goes up to 32 PSI and the cleaning system stops working or switching zones. The flow out of the first five zones is strong so I don't think suction is an issue. This still is happening after taking all the pop-up heads out so there shouldn't be a pressure issue there. I replaces all the parts of the valve that came with a rebuild kit so the valve should be ok...

What could be causing this? Could it be a leak or clog in the plumbing going to the 6th zone? That's the only thing I can think of...

 

[YippeeSkippy]

Hey there sounds like a clog to me.

 

[silver_bullet]

There was some small debris in the filter going into the valve but I cleaned it and still have the same problem. If there's a clog it must be somewhere between the Caretaker's valve and the pop-up heads I removed.

How can I safely try to fix the clog?