5gpm Udor pump swap

Looks like 15w40 is the general consensus as to the ideal pump oil. I bought a new Udor gear drive and it says the gear reducer requires 90w oil. Anything special about that? Something any autozone or O’Reillys would carry? I plan to put anti seize on the key way. Anything else you guys would suggest for prepping for the swap? The new pump doesn’t come with the removable key part…is that already installed in the crank shaft of the old pressure washer? ! Anyone know what size bolts I need to bolt the pump to the engine?

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5/16" with 24 tpi, try a 1" bolt first. I suggest you also use socket hex screws and plenty of stacked washers

Thank you! What will the stacked washers help with?

Load distribution

Use a slightly larger flat first then a smaller flat then a lock if you’d like

Great, thanks!

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Actually that flange looks pretty beefy and if you’re stacking up washers you’ll need more length. You can use a q tip to probe it as you’re holding it up and mark it with your fingernail and then measure it to get an idea of how deep you can bury your hardware, obviously the deeper the better.

Aside from that, make sure you replace that red plug with the yellow dipstick that should have come with it. If you don’t it’ll mess up the pump.

The 90w is gear oil and yes, Autozone et al carries it. Might be 90/100 or something but it’ll work.

Now maybe Udor is different but my General calls for non-detergent 30w, so not sure what is up with the 15w40.

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That’s what oil is written on the pump itself :man_shrugging:

Ok, well for starters it’s going to be thicker :wink:

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A few pics from the swap. The one with the Allen wrench is to show that there is not enough clearance to fit the Allen wrench unless you have a stubby Allen wrench. Also, to get the pulley assembly off, it would be easier with a tool designed to pull the assembly off (forgot what it’s called) but can be done using a bar as leverage. Added 90W to the gear box and works great!

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Get an unloader block and a short jump line to take the unloader off your pump. Same with the filter though less of a concern.

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Allen bolts would be my very last option, Some grade 5 Zinc coated bolts with a hex head would have been best…

Allen head bolts love to strip lol

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No issues with stripping but in hindsight, you’re probably right. Hex head will probably be easier to take off when the time comes. Live and learn lol

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4 bolts my friend, head on down to the store, screw them in and have a beer.

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Oh my goodness, get a thin cut off disk and cut it down to the length you need.

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Unloader block finished. Need to out a 90 degree elbow so the whip line doesn’t stick up so much. Also getting the green spring unloader instead of the unloader I have now. Came with the pump…no idea what kind it is. Thanks for y’all’s advice and input!

Hey man I’m looking to do this upgrade next year. Let me know how well it works for you on the flat work side of things. Also, how much psi are you getting out of it with a SC? Take care.

This trailer will only be used for house washing and rinsing when we do roofs. I have an 8gpm we use for the majority of the work. But the previous pump worked fine for concrete and it’s specs are comparable to this one. May have to post treat occasionally but it’s totally doable.

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Udor calls for standard 90 gear oil.

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