Constant pulse on my TM, can't figure out why...

[White-Magic rebuilder]

The pressure knob goes in and out non stop. Pressure goes to 500 and then goes to zero non stop. Now according to the book it is supposed to go from 0-500 back to zero and stay that way until you pull the trigger. I can still operate but I know a serious problem is coming. Any ides? It is a White Magic 1900 with a 5 cp cat pump.
Thanks in advance,Rob.

 

[cmaster]

Sounds like cavitation usually caused by air entering the system. Try pressurizing the system with a garden hose.

 

[The Preacher]

bad cup on your pump. have you ran your rinse solution dry lately? if so you can get air in the system from that source!!!

 

[White-Magic rebuilder]

bad cup on your pump. have you ran your rinse solution dry lately? if so you can get air in the system from that source!!!

Yes my guys run it dry often. I reamed them and now they got the message. know how I can fix it? I replaced the diaphragm and still it won't prime for the chemical feed.
Rob.

 

[White-Magic rebuilder]

Sounds like cavitation usually caused by air entering the system. Try pressurizing the system with a garden hose.

Exactly how do I do this?

 

[WISE]

Try taking the return tube from your rinse agent jug and stick in the vac port cupping your hand around it to force it to prime. Not sure how that unit is set up (mine has two lines going into the rinse jug), but that has worked for me.


WISE

 

[cmaster]

Sounds like cavitation usually caused by air entering the system. Try pressurizing the system with a garden hose.

Exactly how do I do this?

Hook a garden hose to your water inlet line and turn it on. Turn on your tm and pump some water through it. That should force the air out of the system.

 

[White-Magic rebuilder]

I'll try all the above right now!
Thanks,Rob.

 

[Steve Lombardi]

It sounds like you have a unloader on your machine. I would first check for any visual leaks and repair them first, then check the check valve in the unloader/regulator

 

[Greenie]

Whatever fixes it, let us know cause I have a 1900 on my shop floor that I will be tinkering on this winter, first thing I'm gonna do is replace all these 1/4" lines with some 3/8" I can't believe I'm seeing a 5CP with a single 1/4" line, must be wicked back pressure on the pump?

 

[White-Magic rebuilder]

It sounds like you have a unloader on your machine. I would first check for any visual leaks and repair them first, then check the check valve in the unloader/regulator

Thanks, could you be a little more specific? I tried all above and nothing worked. Still cavetates and no chemical pump action.

Greenie, if your tinkering leads to any simplification,please let me know asap!!
Thanks,Rob.

 

[John Olson]

Did you replace the seals in the pump? You said they run it dry so your High Pressure Seals are more then likely toast. Your chemical problem is most likely un-related. I would go out and look at the WM 1900 but it is on Greenie's floor now

 

[RichardnTn]

Rob,
Unscrew the pressure regulator and run it with the pump on for a few seconds, if your not sure that you have everything out of the regulator, put a container in front of it before you turn the pump on.
Check the pulsation dampener, some models use a hose, other use a gas filled diaphragm. It doesn't have to be totally empty or ruptured to cause problems. If it's ruptured, you will see water if it is low, usually any motorcycle shop can pump them up.(Shocks on bikes)
Plug the chemical feed line going into the pump at the pump. If that fixes it, it getting air thru the chem. feed. If not, unscrew the check valve covers one at a time and check for debris, broken spring, teflon seat...If that is not it, check and see if you have any loose bolts on the head. Sometimes they can loosen enough to allow air to come in the back between the case and pump. If that's not it, time for a seal kit....if it gets to this point, opt for a dry/hot kit and forget about problems with the techs...Hope ya get it, Richard R

 

[cmaster]

I'd check or replace regulator/unloader valve now.

 

[Steve Lombardi]

lets go back to the beginning of the problem. Is It a pressure problem or a chemical problem that you are having with your machine? First of all your pump has to be running properly before determining your chemical
problem. What model pump do you have on your machine? You need to determine if you are flowing the proper volume out of your pump. Typically most pumps in this industry flow about 3-6 gallon per hour. If you do not have the volume at the rpm's that the manufacture specs. you will have no pressure. (think of a garden hose. If you open it up you will have maximum flow. Then put your thumb over the opening and you create back pressure which will cause you to have pressure behind it. If you did not have the flow you would not be able to restrict it to cause pressure.)