Main Category > Epic or Easy Lawn Hydroseeing Equipment

Pump rebuild

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Amazing how much activity there's been in this forum in the few days I've been out of town.  (Couldn't get out of taking the family to Disneyland...)

No matter how long you've been hydroseeding, pump problems can stump you.  As I read this thread, I agreed with just about everything everybody said, especially a suction leak.  Glad to read the fix was relatively easy.  But I thought I'd throw my 2 cents worth in anyway...  
--- Quote ---Originally posted by muddstopper
The suction gasket, if it was letting the pump suck air could cause the problem but just because the flapper is gone doesnt mean it will not pump. The flapper is only there to keep water from draining back out of the pump and into the tank. Whenever you are pumping it is completely open anyways. I actually took the flapper out of my pump so I could pump water back thru the suction line in the event of a clogg...
--- End quote ---
 My Finn doesn't have any kind of a flapper (nor do the Demming pumps found on a lot of Bowies).  At the end of each job, I hook the hydroseeding hose to the high pressure Honda pump on my storage tank (never did like the way Nurse Tank sounds) and blow the mulch back through the pump into the machine.  I was planning to take the flapper out of the pump on my 150 gallon Turbo Turf, but sold it (to my friend Andy) before I got the chance.

I did not read anywhere in this thread the possibility of an engine running too slow.  So I thought I'd throw this response I got a while back from an engineer with Finn Corp:
--- Quote ---Doug Wysong T-30 uses Kohler 15 hp engine...  The impeller size is 6-1/8”.  The hydraulics are the same as the T60 including the pump/motor/valve and drive coupling to the engine.

The T60 uses a 25 hp engine...  utilizing all the same parts as the 30 with the exception of the impeller, which is 6-1/2”.
Running the larger impeller will increase flow by 6%, pressure by 13% and power required by 20% for a given speed.  If we go to the maximum impeller we discussed, flow increase is 9%, pressure is 20%, and power is 31% compared to the T30 at a given speed.

We discussed your current engine may not be running at full rpm.  As an example of what this will do, the same calculations can be made as with the impeller diameter changes above.  You mentioned the engine running at 2200 rpm.  If this were so, pump performance would be flow reduced 39%, pressure would be reduced 63%, and power required by 77%.  If we give it the benefit of the doubt and say it is running at 3000 versus the 3600 it is supposed to be at, these reductions are still 17%, 31%, and 42%!  For a unit that is suppose to push hose and is rated at 60 psi, that engine speed loss of only 600 rpm will reduce the available pressure to 42 psi.
--- End quote ---
What that mans is the continuing pressure problems I've had with my Finn T30 may be due to the engine running too slow...  Guess I should have the RPMs checked?


--- Quote ---Originally posted by Unregistered
I have an easy lawn l90 and the pump is not pumping like it used to.  I figured that it would be worth a shot to try new shims and seals first.  I dont quite know how to go about getting the impeller off the shaft to be able to put the new shims on.  If anyone knows please let me know.  Also, is there any place that you can get cheaper parts for the hpv8 pump? the dealer wanted $440 for the impeller alone.
--- End quote ---

Not all pumps are the same but, the shims usually go behind the wearplate to get the plate closer to the impeller. Some pumps have gaskets between the housing that can be removed to tighten up the clearances. I cant say for sure about the Easylawn pumps since they are threaded on the shaft, but you probably will not be able to shim the impeller, to do so will space the impeller away from the seal and probably cause a leak.On my old Banjo pump, I made a shim out of sheet metal, I forget which gauge but different gauge steel has different thickness, I then placed the shim behind the wearplate to move the wearplate closer to the impeller. You have to dismantale the pump to get to the wear plate but the impeller half of the pump can stay attached to the engine. The banjo wear plate is held inside the pump housing with two screws. Just remove the screws and the wearplate, and use the wearplate as a template to make your shims. Only special tool you might need is a pair of tin snips to cut the sheet metal with.  The banjo impeller doesnot screw onto the engine shaft so I was able to use a feeler guage to set the clearance between impeller and wear plate and then tighten down the clamp/coupling  that holds the impeller to the engine shaft. I suggest that you measure the clearance between the impeller and wearplate before you disassemble the pump. Easylawn should be able to give you the proper measurements, probably around 40 thousant of an inch. A hacksaw blade with the teeth ground off makes a good feeler guage to reach inside the pump. The ones I have used measure 40thousnt in thickness. The lenght of the blade really helps when you are sticking it inside the pump, and automotive feeler guage is just way to short.


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