Comet horizontal pump

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
267
Messages
6,640
I went to use my personal pressure washer this morning, go through the same start up procedure as usual.... Only the only pressure it built was from the hose not the pump... Definitely wasn't 4200 psi. Worked great last week when i used it.
I know very little about pressure washer pumps so it's time to learn.
20210509-141834.jpg
 
Last edited:

upupandaway

Well-Known Member
Joined
Jul 3, 2015
Threads
36
Messages
620
Is it working at all? weak but some pressure??
When u pull the trigger do u hear anything change?
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
267
Messages
6,640
Is it working at all? weak but some pressure??
When u pull the trigger do u hear anything change?
when i pull the trigger with the a tip on, water sprays maybe 10 feet.... but with very very little pressure.
when i pull the trigger there is no change in engine RPM's.. generally i can hear the engine speed change very slightly when i pull the trigger.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
93
Messages
11,589
Scrubcadet10,

Since I don't send PMs, Emails, or post files here I suggest you pm (my cousin) AVB over on Jacks Small Engines forum and he can send you copies via email of the IPLs and service manual for the Comet Triplex pump (much easier to read than one their website currently) if you ask nicely.

Can be a check valve, pressure seals, or even the unloader. Also note there is three versions of through shafts 5/8, 3/4, and 24mm so you would need both the old IPL and the current IPL.
 

upupandaway

Well-Known Member
Joined
Jul 3, 2015
Threads
36
Messages
620
On mine, the pressure relief(unloader) was stuck open. Find the spring. The nut applying pressure to the spring, loosen the nut. Hit the trigger a few times. Doing so on mine got the 'plunger' of the unloader to move knocking it loose and working properly.

If still no go, remove the whole pressure relief assembly and clean it with some CLR or the like to remove the mineral deposits.

If u don't have a pressure gauge(like mine) remember how many times u turned the nut.
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
267
Messages
6,640
me and pressure washer pumps aren't going to get along.....
the unloader valve is where? the part number list doesn't show it, or at least call it an unloader valve....
and here's what i did this morning, i removed the assembly that is under cap #91, unscrewed it from the pump (assuming it is the unloader, parts list doesn't call it that) (that regulates the pressure), it was very stiff to move and sticky, i reinstalled it and left the cap #91 and the spring off, just revealing the flat head screw, with the pump running, whenever i would press that screw down it would build *some* pressure....nowhere near the 4000 psi though.

1620751846812.png
 
Last edited:

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
267
Messages
6,640
okay, i removed the unloader again, WD40'd it and got it working back and forth smoothly.. reinstalled it, fired it up.. had great pressure. working like normal. i shut it down. waited a few minutes, fired it back up. very very low pressure again....
 

Scrubcadet10

Moderator
Staff member
Joined
Sep 24, 2017
Threads
267
Messages
6,640
Finally got the new valve in the mail, put it on, adjusted the pressure... I guess need to use a pressure gauge to get it exact but got it close by "feel", works great!!
 
Top