Cat 3535 pulsating at start of rinse

[Ultra Shine]

Guys I have an I 5000 from D&S wash. After my last pass of soap and the rinse cycle begins my cat starts pulsating , the pressure drops to about 300 psi and slowly ramps back up to 1200. My tank is full of water and externally my lines seem to be fine. After about eight seconds the pressure builds back up and is fine through the rest of the wash cycle.
Any idea ?

 

[waright]

if you have the softstart solenoid on it, that can cause some issues sometimes.

 

[Ultra Shine]

if you have the softstart solenoid on it, that can cause some issues sometimes.

It has a starter and it seems to be working correctly.
If I try it manually I can not repeat it

 

[Damoni88]

Check all valves and seals.

 

[Ultra Shine]

Every things seems to be opening and closing just fine. It will no duplicate in manually mod. That’s the odd part

 

[MEP001]

Is it happening right after the presoak is applied? You might have a bad check valve that's letting air back into the pump, and it's pulsating/running low pressure until the air is purged.

 

[Ultra Shine]

Is it happening right after the presoak is applied? You might have a bad check valve that's letting air back into the pump, and it's pulsating/running low pressure until the air is purged.

I run a pre soak and then stage 2 . Yes it happens after last pass of soap when rinse starts.
I will try that .

 

[Ultra Shine]

Hot water valve for soap passes. Either new valve went bad or it can keep up all the sudden. I took power off and works fine

 

[bobcat9095]

Mine was doing the same thing and I backed my pressure down to just under 1200psi and it fixed it.

 

[Ultra Shine]

Mine was doing the same thing and I backed my pressure down to just under 1200psi and it fixed it.

Thanks, I tried that too. Mine is only running at 1000 now. I disconnected the hot water valve and put hot water to my holding tank.
Either the valve is junk or the hot water pressure is to high .