I’m new, but I have been reading and researching. I bought a 5 gpm 3000psi a year ago (NorthStar) It was for personal use… Ok I was involved in my church so I went overboard to help with cleaning. It was great but it was direct drive. I started buying more and more accessories. cleaning more and more and hit the productivity wall. So I just traded my one year old machine with just under 200 hours for a 7ish year old TUFF hot cold skid mount. It “has” 400 on the hr meter and the meter is working. The previous owner had it in a shop to wash large equipment but it wasn’t used often at all. The fellow I traded with wasn’t very mechanical but worked in the washing industry for over 7 years. Ok I told you all that to tell you this. The pump quit working two weeks ago on him and I knew I would most likely be replacing it. It is a Legacy TT-3555. He said it threw a rod out the case but the was no hole in the case. Hmmm. I pulled it off and opened the crank and all looked good except that milky stuff that once was oil. Pulled the head and found a plunger shattered and the bolt that held the plunger on was broken off and the rod end mashed. There in no end play on any rod. Should I buy parts and fix or go with a new pump? Cost is a concern but if it will last a long time with proper maint I’m up for the fix but don’t know what a plunger rod costs. Any idea what it would cost for parts? I have added two pics for you viewing pleasure. I Thant all of you for your contributions in advance and for what you have contributed to this site.
Wow. That’s some wreakage. I’m no expert but personally I’d definitely just buy a new pump. You can replace all the seals, plungers, valves and maybe the rod (not sure on that one) and you still might have head damage. That ceramic had to go somewhere. You don’t have to replace with a Legacy, you’ll find all major manufacturers make an equivalent pump.
I will take your advice. I just finished getting it apart and the bearing on the opposite side of the pulley is making a tad bit of noise so it would need replaced also have not priced it. So it will go on the shelf till winter.
I have a question about going to more gpm.
I gave a Honda GX630 20hp running this 5.5gpm 3500psi pump at 1450rpm. I would like to go with a 8gpm 3500 or a 7gpm 4000 psi. I’ve looked at the mfg recommendations, and did the math and read some conflicting comments and recommendations from different pump mfg. I am seeing a range 17.3 - 25 hp required on same pumps rpm and output same also. The engine with the current pump barely grunts at full psi. What do you think?
Here’s the formula to figure out what size engine your going to need for a certain size pump and PSI your looking at: (GPM x PSI/1450) x 1.5
If you throw in your 8gpm pump @ 3500psi or 7gpm @ 4000psi either one your going to need at least a 28hp engine. The generator will also need a couple of HP tacked on to the engine so for your #'s above you’ll need at least a 30hp engine.
I have found a comet pump NOS for $250 7gpm 4000psi. Needs 25 HP. I don’t have a generator in the mix. If I back this down to 3000k do you think I’ll be good? 21.5 hp. I could over drive the speed by say 100-200 rpm. I know that would be taboo but I would think that would be a fudge tolerance that shouldn’t kill the pump in a year or two. I’m thinking $250 new pump used 6mo old pump put back in service over winter and new pump becomes backup.
Well I got a pump installed it and got it running. I’m pushing 7 gpm and 3500 psi. Engine is turning at 3500 rpm pump is at 1680. I was able to get 4000 psi and the engine had more to go. I backed the pressure down to 3500 that seems to be enough. Either Honda is conservative on their specs or NorthStar has over stated their specs. I know that this should not have worked according to the paper so I feel very lucky that this has worked out. Thank you all for your help.
