Build a Pressure Washer?

[danski0224]

Hurricane Milton wiped Pressure Pro off the map two days after my parts order was placed, but before it shipped.

I wasn't sure when or even if anything would happen, but I received notice that the order shipped a couple of days ago.

Waiting to see what shows up.

Of course, it's a little chilly to mess with it at this point.

 

[MileHighRover]

Thanks for the update.

 

[danski0224]

Parts showed up yesterday.

No time to mess with it right now.

 

[danski0224]

Some progress

 

[MileHighRover]

Looking good.

 

[danski0224]

I ordered the belt, which might take up to 10 days to get.

Not much room for adjustment. A little more than halfway in the "loosen" direction, the pump and engine have interference. Easiest thing to do will be to re-drill holes for the pump and enlarge the cutout in the guard. I'd have to check on belt availability though.

The pump I got is offered as a stock item on these pressure washers, but they are V belt, not timing belt setups.

Looks like the engine shaft might need to be trimmed. I don't know if new production versions have shorter shafts. There's only 1 set of slots in the base that work.

Unless I picked the wrong baseplate.

Looks like I also have to figure out how to move the pump oil sight glass to a useful location.

 

[MileHighRover]

Why did you opt for the timing belt setup and not V belt?

As long as you can use a mirror to check the oil level, I wouldn't worry about moving the sight glass. The pump isn't going to use oil so really the sight glass will only be used during oil changes.

 

[danski0224]

Why did you opt for the timing belt setup and not V belt?

Just because.

I thought it might be a little more durable.

 

[PoorUB]

The instructions showed plain old silicone caulking, from a site linked above.

I wouldn't do that anyway. Doesn't make sense.

When I did HVAC service, if we changed a condenser fan that the motor shaft pointed up, we would cover the end of the shaft and fan hub with silicone sealant. Years later we could go back, loosen the set screw on the fan and pull it right off. The shaft and bore of the fan hub would look like new. The fans and shafts we didn't use sealer were rusted in place and removing the fan required a puller and often damaged the fan.

 

[danski0224]

So, this thing has been a PITA.

Lots of places sell a part called a K7 unloader, and I have yet to see a site that does not describe the connections as "NPT". The spec sheet clearly states otherwise.

Well, they are NOT NPT, but rather BSPT and BSPP. Both are *close* to NPT, but not the same. A NPT fitting will go about 1.5 - 2 turns in by hand and then bind up a bunch.

I can only ASSume that nearly everyone using one of these parts just takes a NPT fitting, winds it up with thread tape, and just runs an NPT fitting onto it. I have yet to see a video or picture online of a K7 unloader with additional adapter fittings installed.

I took a guess on the last part needed, and it arrived and fits.

If I bought an assembled unit or paid someone to put one of those K7 unloaders on it, they would have just **** it in.

Now I wait for the remaining fittings that the online place screwed up on.

 

[MileHighRover]

Sometimes it's worth the extra coin to buy an assembled unit. Sometimes.

 

[MileHighRover]

Why did you go with the K7 unloader? Something like the VRT3 is a well made, high quality unloader that is used on a ton of machines. Rated at 4,500 psi and 8 gpm. The one pictured has a bypass but they make one without. I know it's too late now, just curious. So far this build seems like you're taking the hard route.

VRT3 Unloader

 

[danski0224]

Sometimes it's worth the extra coin to buy an assembled unit. Sometimes.

I suppose, if I was going to stay with the standard and typical "4 gpm/4,000 psi" model that everyone sells.. but I figured I could put together something a bit nicer for the same, or close to the same, money.

I had no idea how "challenging" it is to get some of the bits and pieces outside of the club.

If it isn't bad *** when it's finally done, I'll be a bit miffed.

 

[danski0224]

Why did you go with the K7 unloader?

Supposed to be less kickback.

Flow unloader vs pressure unloader.

I've only used it a few times for an extended period (before it broke), and it's exhausting. I don't like the kickback on a ladder, either.

Extended period for me = just about a full 8 hour day using the pressure washer, including moving it around and such. Not dragging it out for a 1 hour job.

It'll be relatively easy to switch to something else if I don't like it or it doesn't work as expected, as there are plenty of "ready to go" plumbing setups for standard unloaders. Doing the K7, with the right fittings, has been a pain. But, almost there.

Seems like almost all of the hydraulic fitting places online drop ship from the same places, and you don't find out about backorders until *after* the order is placed. They almost always claim to "have it in stock", but nope.

 

[danski0224]

So far this build seems like you're taking the hard route.

Maybe, but it's what I wanted. Or, I think it's what I wanted.

I suppose I could have just whipped out the plastic and got a new one...

Won't know until it's up and running.

The difficulty has been getting some of the parts.

I almost threw in the towel, but was too late to send stuff back, so gotta get to the end.

 

[MileHighRover]

You'll have a really nice unit when you're done. It's easy to pull out the plastic but where's the fun in that? Going back to the start of this project, think about all the fun you've had!

 

[danski0224]

Closer.

 

[MileHighRover]

What else do you need to do?

 

[danski0224]

Not much.

Got the drive aligned yesterday.

Been busy.

Almost afraid to put water in it and see what happens

 

[danski0224]

Got it running, and it is bad ***.

Absolutely no kickback or pulsation. Starts super easy, don't have to hold the trigger.

Pressure is a bit lower than expected, but have 4.5 nozzles instead of 4.0... 4.0 are coming. Will probably order a 3.5 to see what happens.

I don't know if the other setup was cranked super high, I didn't have a gauge on it. But honestly, it was a bit much.

The K7 seems to be a 3,000 or 3,500 psi rated unloader, so maybe that's just what it's gonna be. Mine doesn't have the sticker on it, so it may be 3,000 psi. I didn't know about the sticker when I bought it.

I wouldn't be surprised if stuff is over rated, like stereo amplifiers.

Drive pulleys should be spot on, but I may dig out the strobe and check pump/engine RPM. Swapping pulleys around will get super expensive unless I can find them on eBay again.

 

[mike93lx]

No surge must be amazing

 

[danski0224]

I can one hand it.

Had to use both hands and be ready for it before.

Night and day difference.

Well worth the aggravation of getting it put together.

 

[MileHighRover]

Well, I'd say that was a job well done, sir.

 

[danski0224]

Drive side. There is a cover, obviously not installed yet.

Going to need to cut some of the engine shaft off in order to get the cover installed.

 

[danski0224]

Got the strobe out, engine was only 200 rpm high, which made the pump a little high.

Got everything set, and the drive ratio is pretty much dead on with the pump just over 1450 rpm.

Running 2500 psi with a 4.5 orifice nozzle.

Have 4.0 and 3.5 orifice nozzles on the way.

This pump is "only" 3,500 psi and the previous CAT was "4,000", both claim to be 4 gpm.

I'll have to see what the different nozzles do for pressure.

My K7 doesn't have the sticker on it, so those seem to be 3,000 vs 3,500 psi.

The 3,500 might be nice, but if it means another unloader, I'll have to see how it works for a bit first. Have a couple of small jobs to do with it.

Kinda wish I had a gauge on the other one, just for reference.

It feels different, ignoring the kickback. There definitely was more "backpressure" coming from the other setup while in use.

Maybe I'll put a gauge right on the head (temporarily) just for grins. I've got some fittings between the head and unloader, hopefully not too many.

 

[MileHighRover]

You do have quite a number of fittings but it makes virtually no difference in pressure loss, certainly not enough for you to notice.

Cat Pumps has a great reference library. You can read up on pressure loss due to fittings, valves, metal lines, hoses, etc., among other things pertaining to pressure setups. Cat Pumps Reference Documents

 

[danski0224]

I really doubt that the few 90 elbows are knocking off ~1,000 psi, based upon published specs for the pump.

However, I can see 3,000 vs 3,500 based on descriptions of available K7 unloaders.

The pump i have should be generating 3,500 psi at 4 gpm. Those are the specs.

I have new nozzles coming.

 

[MileHighRover]

The smaller nozzles will increase the PSI but will lower your GPM. You can use a 5 gallon bucket and a lid with a hole cut in it large enough to stick the nozzle through to measure the GPM of each nozzle.

 

[danski0224]

I took the nozzle off, and it nearly filled a 5 gallon bucket in a minute. Certainly 4 gallons of water.

The 3.5 nozzle only moved the psi up 250 to ~2,700, but I didn't readjust the unloader.

Given that the pump is claimed to be 3,500 and an "unmarked" K7 is rated at 3,000, I'm guessing that the machine is "right there".

I'm almost positive that I ordered a 4,000 psi and 4 gpm pump, but the number on the pump crosses over to 3,500 psi and 4 gpm. The seller could have shipped the wrong one by accident... or on purpose. They all look the same within the same class and manufacturer, and the only way to be sure is to check the unit part number.

Whoever may have messed up, it's way too late to send anything back. I had a lot of stuff going on at the time and certainly didn't think to verify the part number on the pump itself. Pressure Pro has/had a "4040" pump that's supposed to be 4,000 and 4.0 gpm, and that's what I ordered. But it's not what I got from the vendor.

Changing a working pump is an option, and an expensive one.

I did look into a "marked" unloader and ordered one. I verified that it's supposed to be "marked", and if it isn't, it's going back. I can re-use the plumbing parts.

Just got the crank snout cut yesterday so the belt cover can be installed, then I can use it and see how it works.

At least the engine RPM and drive ratio are spot on.

So that leaves the unloader (which could be defective), fitting loss or a defective pump (also probably not likely).

From what I have seen, these unloaders get adjusted until there is a dribble of water at the by-pass during operation (wand trigger pulled), and that's it. Still waiting on new 4.0 nozzles.

 

[MileHighRover]

You need to have the nozzle on when checking GPM. With a 3.5 nozzle and 2,700 psi you should be around 2.9 GPM. The 4.5 nozzle at 2,500 psi should put you around 3.6 GPM.

 

[danski0224]

I'll have to dig it out and check it again.

Same engine.

Used it for about an hour today, and for what I was doing, it's working mostly all right. Certainly nice not having the kickback or "spike".

The difference in output was only really noticeable when attempting to blast off the dirt from the edge of gutters. The other one seemed to work a little better.

It may also be the fittings, especially the tee right off the head.

I found some stuff that should work better.

And the "unmarked" vs "marked" K7 has a stated 500 psi difference in ratings.

But at least it was running for the job. Mom is happy.

 

[danski0224]

So there is/must be an issue with the pump. The pump should be putting out 3,500 psi, and it's about 700 psi off. Pump is a General TSS1511.

I picked up another unloader, and the pressure readings have been nearly identical no matter what I have done to the plumbing. My other one was "marked", just didn't look closely enough. *******.

Continuing to turn the adjustment bolt once the water discharge at the bypass stops with the trigger pulled does not result in an increase in pressure.

In order to bring up the output psi based on pump RPM, it would need to go from ~1,400 to ~1,900. The 67 tooth sprocket needs to be 51. I don't need to draw from a tank, but that is almost a 30% increase in RPM... and GPM will also go up.

Unfortunately, any kind of return window is long closed, and they only have a 90 day manufacturer warranty.

Otherwise, it works, and I am in no rush to blow more $$ on a different pump. A 59 tooth sprocket would split the difference, at least in theory... but it's either 60 or 56.

I sent an email to the vendor I ordered the pump from. I am certainly not expecting them to take it back, but if they have any suggestions, I'm open to them.

I had a bunch of BS going on that prevented reasonably quick assembly of this project (besides a hurricane wiping out a major parts distributor and my order), but the takeaway here is to not order stuff that can't be installed/tested/used right away, unless one is OK with possible problems later that are now on your dime.

 

[danski0224]

For anyone still following along, I did email the vendor I purchased the pump from, and honestly had zero expectations.

Surprisingly, they replied to my inquiry, and told me that the pump I have is the same as the private label one I ordered and that it is capable of 4,000 psi at 4 gpm at 1400 rpm.

The K7 unloader was described as "finicky", and after a couple of emails, it was suggested that I try a 0 orifice instead of the 1 orifice that ships with the unloader I bought- which "should" have worked based on specs.

Part is on order (I ordered it through them), so hopefully this will be resolved.

Based on the description, I am actually getting what is called out as the "nozzle" on the exploded parts diagram, and there is a part called an "orifice" behind it. I asked about the "orifice" on the diagram and was told that I don't need it. I suppose I could try that before throwing in the towel

If that doesn't do the trick, or if it doesn't get me to at least the published spec for the model pump that I have (3,500 psi), then I will have to try the old unloader from the previous pump. might do it anyway, if there is time to mess with swapping stuff out.

The pump protector stuff that I have purchased in a can has not only been cut in size, but the price has almost doubled since I bought some.

 

[Milton Shaw]

When I was a teenager, 60 years ago now. I saw the biggest pressure washer I have ever seen. It had a Ford industrial V8 engine on a 8" four belt drive to a 5' pulley repeated to a 8" pulley 6 belt pulley to 5 foot pulley on the pump. It was rated at something like 14 gallon a minute at better than 20,000 psi. It would wear out two men and a diamond nozzle in 30 minutes or so, and then a repeat. They used it to clean paint booths at car assembly plants. We were working on the trailer at a summer welding job. I built one myself on a 1 hp lifting brush motor, two piston pump I picked up some where. It worked and the pressure I was running it was rating the motor at better than 3hp output. The brushes were not lifting often. I finally got a Northern pressure washer with a 270 Honda motor, still have it.

 

[mike93lx]

When I was a teenager, 60 years ago now. I saw the biggest pressure washer I have ever seen. It had a Ford industrial V8 engine on a 8" four belt drive to a 5' pulley repeated to a 8" pulley 6 belt pulley to 5 foot pulley on the pump. It was rated at something like 14 gallon a minute at better than 20,000 psi. It would wear out two men and a diamond nozzle in 30 minutes or so, and then a repeat. They used it to clean paint booths at car assembly plants. We were working on the trailer at a summer welding job. I built one myself on a 1 hp lifting brush motor, two piston pump I picked up some where. It worked and the pressure I was running it was rating the motor at better than 3hp output. The brushes were not lifting often. I finally got a Northern pressure washer with a 270 Honda motor, still have it.

I wish I took a picture of the rig that we hired to clean out a chemical tank a couple years ago. It was either 30 or 40k psi, no idea on flow rate, and had a massive diesel powering it. It was at least 20' of trailer.

I think they're normally called hydroblasters

 

[Milton Shaw]

I wish I took a picture of the rig that we hired to clean out a chemical tank a couple years ago. It was either 30 or 40k psi, no idea on flow rate, and had a massive diesel powering it. It was at least 20' of trailer.

I think they're normally called hydroblasters

When I saw that one cell phones had not been thought of even in SiFi. Film camera's weren't much better than Brownies.

 

[danski0224]

Probably a final update to this.

I received the "0" orifice for the K7 unloader, and it did 2 things. Brought up the pressure to about 2700 instead of 2500, but if I put a 3.5 nozzle on the lance, there was no pressure.

Took the unloader off and hooked the gauge and hose right up to the pump (kept trigger pulled) and it can easily do 4000 psi.

Installed a K1, and it's running 3200 full open. Have a little more with the 3.5 nozzle (but I know that this isn't "right"). I have to re-check engine RPM under load, but I have a feeling that this is it, unless I go back to a pressure activated unloader.

Unless I am missing something painfully simple, there seems to be no way to get the rated output from this with a flow activated unloader. At least the 2 that I have tried.

The K1 is rated to 3600, so it's close to that.

 

[danski0224]

Well, this is it.

It was suggested to try running it without the unloader to verify pump operation, and the pump will quite easily put out 4,000 psi pretty much where the idle is set at. Of course, you can't let off of the lance trigger while doing this.

Put the unloader back into the circuit, and the best it will do is 3,200- with the screw backed all the way out on the ZK1 unloader. I ran the screw in a little bit and have 3,000 psi on the gauge.

This one did better than the K7 unloader. Either is rated for 3,600 psi, but there seems to be no way to get that out of it. There's only two 90 degree fittings, one is the brass mounting block. It's quite a bit of extra weight to hang off of the brass pump head, not to mention about 10" of lever arm without an elbow in it.

I actually tried radius JIC fittings, but they would not stay tightened with the vibration and I didn't notice an appreciable difference.

There is a smaller 3/8" BSPP outlet ****** for this unloader (the center hole is a bit smaller), and it just caused problems with pressure spikes with the lance trigger released, so I put the original 1/2" BSPP outlet back on. Oddly enough, the installed 1/2 to 3/8 reducer does not cause the same issue.

All of these unloaders have British threads, and SAE NPT fittings will only engage with about 2 turns. Mine has the BSPP adapters.

I had to run something other than braided vinyl hose and worm drive clamps on the bypass hose because it was blown off of the barb fitting.

Also had one of those popular garden hose inlet strainers with the clear plastic held in place with o-rings, that didn't work out so well, it came apart. Junk.

It will fill a 5 gallon bucket about 3/4 full with a 4.0 tip, so it is close to 4 GPM. Somewhere between 3.5 and 4, without actually measuring it out.

Next is to get a few hours behind the machine and see how it does. If I need the higher pressure, I will have to put a regular unloader on it.