# Pressure washer pump rebuild?



## keegantimber (Jun 3, 2019)

I have a gas powered pressure washer with a 2700 psi Comet pump. Recently noticed oil (frothy white) coming out what I believe is a vent on the top of the pump...when it is running. Appears as though I have an internal seal leaking water into the oil cavity. Anyone have experience rebuilding a smaller Comet pump and any tips ?? Thanks


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## ironman_gq (Jun 4, 2019)

We always just source a new pump, usually higher quality ones. Usually around $200 and you know it's going to work instead of rolling the dice.


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## keegantimber (Jun 4, 2019)

Thanks. Im actually having a hard time sourcing parts for the model number stamped on the pump.


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## ironman_gq (Jun 5, 2019)

horizontal or vertical? do you have a picture of the pump?


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## ironman_gq (Jun 5, 2019)

https://www.northerntool.com/shop/t...Sh7mahxHf3KFGh5ouRDkFMZPBBVvjzeRoCII8QAvD_BwE


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## keegantimber (Jun 5, 2019)

Its a horizontal pump. Thanks for the link but Im in Canada. I found a somewhat local source for parts. Debating a new pump vs attempting a repair. Its about 10 yrs old but really hasnt been used that much. Gonna take it apart to see if I can diagnose how water is getting into oil cavity.


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## ironman_gq (Jun 6, 2019)

Any chance you let it run without spraying it? Those pumps are largely water cooled and dead heading them causes them to heat up very quickly which is really hard on the internal seals.


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## keegantimber (Jun 6, 2019)

Well ya...but only for a few minutes. Would that heat up that fast? I know not to let it run say 10 mins....


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## ironman_gq (Jun 6, 2019)

Depends, we had one yesterday that got hot enough to foam up the oil after just a couple minutes and the pressure rose enough to lock up the trigger on the gun, kid using it stopped to dig a rock out of a set of tracks. Couldn't touch it without burning your hand, water was trying to boil off of it. Not sure if it's fried or not yet, we shut it down and left it to cool off.


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## keegantimber (Jun 6, 2019)

Dont think I ever got mine that hot. Gonna take it apart soon. May post some pics.


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## keegantimber (Jun 6, 2019)

So I got mine off and apart today. Determined there are 3 pistons with 2 seals per piston. One seal on the water side and one seal on the oil side. I need to figure out how to get the brass bushing (packing as they call it in Italy) out so I can access the inner seal. Will get a price on these seals then make a decision to repair or replace with a new pump.


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## LegDeLimber (Jun 15, 2019)

Think like getting the bearings out of a saw case?
Might be able to run bolts into those 4, outer/corner holes of the case, to bump on a SOLID surface.
I'm thinking of heating the housing then using ice chunks to chill the brass to get them out.
Get some CO2 - "dry ice" as it would be better than frozen water due to the temperature difference.

IF you try it, be sure to set up the work place first.
Do a dry practice run while wearing your gloves, etc, and see what causes problems with the routine.

Don't want it to bounce like the middle of a work bench will. 
If you couldn't -easily- drive a nail into the work surface, then it's too flexy!

Make sure the bolts are screwed in at least -twice- (I'd prefer 3x minimum personally) their diameter so as to not tear out the threads in the holes.
Also make sure the bolts are long enough to allow the bushings room to drop all the way out!

Use a bit of thought on just how hard to bang on things and be sure to land it squarely on ALL of bolt the heads when you do.

Putting them back in may be a bit more involved.
Beating on them (even with a block or socket under the hammer) will likely mush the holes in and then your plungers will gall and hang up in the bores.
Arbor press and some dead true tooling and work surfaces or you'll just cock the bushings and maybe even crack the housing 
Plus you get to start all over with the heat & beat process.
Then after you get them in strait, might be prone to leakage around them from whatever looseness any distortion or scraping of the holes that the crooked install caused.

This is just what popped into my mind as I saw the thread and images.
Based on general things that kill many projects. 
Hopefully, someone who has rebuilt a pump will come along with some real world knowledge!
Kinda sucks, but sometimes the (proper) tooling costs more than just buying a new unit. 
Just have to do your personal math as to if it makes sense to gear up for the repairs or just replace the unit.


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