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Hypro pump noise?

Discussion in 'Pesticide & Herbicide Application' started by mark2, Jun 24, 2002.

  1. mark2

    mark2 LawnSite Member
    Messages: 93

    I have a hypro d-30 pump that makes alot of noise. The pump is well used I bought it pretty cheap.

    I have put new valves, diaphrams, rebuilt control valve and it still seems loud like there are bad bearings.

    anyone have any ideas??
  2. tremor

    tremor LawnSite Bronze Member
    Messages: 1,476


    If it's quiet at low presuures & noisy at high pressures, I would look at the gear reduction unit. nThe GR was probably made the same company that made the engine. But it could also be a Hypro GR.

    Briggs & Stratton motors have very close cut gears on their GR's. As such they whine a little when new, but quiet down after break-in. Then they whine some more when they're shot or dirty & getting ready to fail.

    Honda motors are very loose & sloppy even when new. They make a LOT of noise at all stages of their lives when the pressure is turned up. Very reliable though.

    Kawasaki makes a very nice GR that is both tight and quiet. Time will tell, but if I know Kawasaki, these should prove just as reliable as all the rest.

    Hypro also makes a GR unit for their own pumps. It's crazy expensive so most OEM's don't use them. I've sold & serviced a few & found them to be no more reliable, but they sure sounded good (quiet).

    Make sure some yahoo didn't fill it up with 80-90 wt gear lube when it was supposed to be straight 30 wt. Check the fluid level too. The motor oil in the engine does'nt migrate into the GR unit. It has it's own fill/drain & check plugs. Look for brass plugs on the bottom & side. If you haven't allready done so, change the oil in the GR. Let the old oil settle in a pan for a while. Then gently pour some of the oil off. Now feel the bottom of the pan between your fingers. Any gritty stuff? Any peices of broken gears?

    Post the type of GR unit if you can. If there is no exterior mark, try to put up a picture or a very detailed description.

    Generally. B&S painted their GR's to match the color of the engine (usually unless replaced at some point). Honda is unpainted light colored aluminum. Hypro is (I think) often anodized black. Kawasaki is more like Honda, but with sharper corners where Hondas are more rounded.

    The pump does have bearings but failure is not common.

  3. I just rebuilt mine.

    If you have a gear reduction on the engine, the couplers make a nast noise all the time and it gets louder as pressure increases.

    Like tremor says, if it's a mounted one and not a coupler it should be some what quiter.

    I have both the hypro GR and a Honda with a 6:1 monted on the engine with a copupler, and the GR with no coupler is much quiter than the other.

    I also use 30wt in both the pump and the GR, but was told to use 80-90 in the GR and found it to be to thick.

    I was also told to use 10w-30 in the pump and just use 30wt.

    Both pumps are the same age and get about the same use, and the one with the Hypro Gr unit has out lasted the coupler type. This could be lead from that one gets stored indoors and the other out doors, who knows.
  4. mark2

    mark2 LawnSite Member
    Messages: 93

    I can't give you a picture but I can describe it a little.

    It has a black plastic dipstick that appears to also serve as a vent.

    It has three aprox. 18mm plugs one to drain and one in each side to use as a fill hole sight I suppose.

    The bolts holding it all together are hex heads.

    The unit appears to be two peice w/4 bolts holding to the pump and 4 holding to the engine.

    The engine is Honda.

    I think the unit was assembled by Viking manufacturing in Florida.

    I took the GR unit apart the other night. It comes apart in the middle. The gear on the pump side is held on by three hex head bolts.

    There was metal shavings in the oil when I changed it. It appeared to be pretty thick oil. When I replaced the oil I used 90w. I thought I was doing it wright.
  5. That's a seprate GR unit, it's going to make some noise and more as pressure increases.

    It is better than one with a coupler.

    I think you have described the one I have. LOL
  6. tremor

    tremor LawnSite Bronze Member
    Messages: 1,476

    It does sound like the Honda unit. I don't like the debris that came out. Let's hope you got it all out. Honda specifies straight 30Wt oil in that thing. If it's 80/90 in there now, I'd drain it again & reinstall 30wt. You may want to change the oil again 1 or 2 times at 4-6 hour intervals to get it all out. You can then also monitor the oil for more shavings. If the problem of metal chunks continues, you'll end up having to replace that GR eventually.

    For those who still use the Morse or LoveJoy couplers; I seem to remember we used to use a fairly quiet urethane spider that did a great job of dampening out some of the noise. It didn't last as long as the bronze spiders, especially if there was any misalignment between the GR output shaft & the pumps input shaft. The bronze spiders are more tolerant of misalignment, but they're much noisier when alignment is an issue.

    I found that a clean well lit garage was the only place to align these things. Use a straight edge & be patient. I wouldn't have a phone ringing anywhere near me while doing this job. Start & finish in a quiet orderly fasion with no one bothering you. Check alignment at multiple points. Then recheck after rotating the shafts (with spark plug removed!) A good selection of washers of a variety of thicknesses is critical for shimming to obtain proper height on old, worn units. Especially if the sprayers ever been dropped or mishandled since some frames are very chinzy & bend easily throwing all kinds of things out of wack.
    Before reinstalling the metal coupler halves, degrease them thoroughly. Use disc brake cleaner on the set screw & it's hole & the key & keyway. After the parts are thoroughly cleaned & dried, reinstall with red Loctite on the setscrew. Don't use the unit for at least a few hours or the loctite wont hold. Any oil or grease will prevent the loctite from working.
    That's why so many of the so called "in season emergency repairs" dont last. No one takes the time to seek proper alignment & wait for the loctite to dry. So the couplers come loose, breaking or damaging the spider often before the tank is empty. So the cycle continues!


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