Last Step Injection Problem


New Member
Jan 18, 2018
Real Name
I have a older prochem blazer XL with last step chemical injection using a general pump chemical pump. I have two main issues. 1st. When I have it set to prime I don't seem to be getting all the air out of the system as there is a continuous flow of bubbles that never go away. Obviously there is a leak somewhere but I just don't know where. I did have a crack in the flow meter but I've since replaced that and it did make a significant difference as I had no flow at all before. I've also replaced all the clear braided lines but that did not make any difference. The other thing I'm noticing is that when I have it set to run I'm getting water leaking into the chemical jug coming from the prime hose. After a while of not using my wand my chemical jug will just start filling up with water until it overflows. I assume this must be an issue with the diaphram on the chemical pump being ruptured correct? How else would water get into the chemical jug? I also notice water leaking from the bottom of the chemical pump when it's engaged even though I have it on as tight as possible. I'm thinking I might have to issues 1. a ruptured diaphram in the GP and second, the three way prime valve must be defective and allowing water to flow back into the chemical jug. Anyone have any other ideas?


Randy Dockins
Premium VIP
Nov 12, 2008
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Randy Dockins
Business Location
United States
It's hard to say, but it sounds like you may have more than one problem. I would start by rebuilding the chemical pump. If you still have a problem I would be looking at the 3-way valve. I'm pretty sure the back flowing into the jug is a check valve issue in the chemical pump. I think it's the check valve that draws from the container is not closing as it should. If you haven't rebuilt it in quite a while I'd plan on doing that. The air bubbles could be the 3-way valve or a bad connection somewhere is letting air in.


Active Member
Jul 31, 2012
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Edward Arnold
Business Location
United States
Chem jug overfilling. chemical pump diaphragm is bad. When you replaced the chem flow meter, if didn't replace the barbs on it I would. I also take the fittings out of the meter and lock tight all the connections. Chemical system has to be air tight.