Low Pressure Problem

Guys, recently changed the oil in my pump (TSF2021) and found water in the oil, so I changed the seals. First time doing this job, but pretty confident I stacked the seals in the right order, and did the job correctly. Now I have low pressure coming from the pump. Bucket test shows flow is about right, but pressure is cut in half. I have changed the unloader, with the same results. Any ideas?

Could you suck air thru the check valves? I assume you are talking about packings when you say you changed the seals. If not, what exactly did you replace? Not sure why you replaced the unloader, unless you knew it wasn’t working. Was the spring moving? Did you set the unloader? If you had pressure before you messed with the pump, you did something. General pumps aren’t really worth rebuilding. They are basically throw away pumps. I would stop while you are ahead, buy a commercial grade pump and get your vendor to show you how to break it down and rebuild it evry 3000 hours.

Assuming it was working OK with the exception of the water in the oil, you changed something, and now it doesn’t work, the first thing I would do is double check what I changed. Since you changed the seals and it’s a new process for you, maybe you put one in backwards, allowing a piston(s) to move water past it the wrong direction instead of through the check valve. I would check those seals again.

What numbered parts see exploded pump diagram did you replace or remove and reinstall?

Thanks for the replies. Yes it was the packings that I replaced. After I replaced them and fired the machine back up, I started having low pressure problems. Replacing the unloader obviously wasn’t the solution, but I had a spare and figured I give it a shot. After thinking about everything i did, I may be onto the problem. When I changed the oil, I also replaced the spark plugs since I had a couple. They were not OEM parts, and looking through the reviews on Amazon, it appears others have had trouble with these spark plugs. I have ordered some OEM plugs, and hoping that will solve the issue. I’ll update the post when I figure it out. Thanks again for taking the time to respond.

Spark plugs aren’t your problem.


This was what I immediately wondered…

Ive had the same tsf 2021 for 4 years now. What makes them disposable? What is a better alternative?

Udor or landa. 4 years for you might be different then four years for someone else. My pumps get about 1500 hours a year and last about 5000 hours without maintenance

I assume you mean 5000 hours between rebuilds? You do oil changes around 500 hours?

I change the oil at 50 hours break in and then never again. It’s just an oil bath. It isn’t going to break down or lose viscosity or anything.

How did you set the unloader?

Still waiting on the answer to this one…forget the “how”…

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im addition to unloader questions, there @are oil seals im addition to the pressure seals. did you replace the oil seals?

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OEM spark plugs arrived today, and after I installed them, she fired up and ran like a champ. This is a link to the spark plugs that did not work. If you buy this package, DON’T use the spark plugs!

Thanks to everyone who replied here. Just to clarify, the “seals” that were changed, were the packings that go around the pistons in the pump. I set the unloader by running the machine with the red tip installed and adjusting the unloader until water barely comes out of the bypass with the trigger engaged. Thanks again everyone.

Spark plugs don’t cause low pressure

Yeah, I don’t understand how replacing spark plugs in an engine that was already running somehow managed to increase the pressure output from the pump. There are parts to this story that seem to be missing.

I always figured landa was like a pressure pro and just assembled various parts together. I now see they are a pump manufacturing company that thinks very highly of thier product but shouldn’t we all. I will strongly consider them when i finally get the opportunity to build my dream rig