Fixing old high pressure washer

[DennisCA]

I tried that this morning but same behaviour. It's not like when the unloader valve activates though, just a rythmic vibration to the whole machine, but the powerwash jet is steady.

There's some slight dripping I see from cylinder 4 but I doubt it can be a cause since it's so slight. Most of the leakage is before the DIY nozzle however and there is some slight leakage on the intake hose. Perhaps all these combined.

I am thinking it might also just be how this washer is. Or maybe inaccuracies in how I made the repairs to the pistons, slight discrepancies in height and thus volume per cylinder might be introducing the issues.

 

[carbon]

With four cylinders it should be fairly smooth. Check valves for debris but some pumps can be like that.

 

[DennisCA]

I'm taking each cylinder valve and checking, checked one cylinder so far and it seems to work. I am checking the high pressure side since I think errors there would be more noticeable.

 

[DennisCA]

I tested one cylinder but I think my test wasn't good enough. The 2nd cylinder was tested and it seems to let water through, but I cannot tell if it also lets some water back. I removed the cylinder top for easier access, then I tried blowing into the removed valve and it didn't feel entirely air tight. So perhaps that's the reason. Might be a good idea to replace all the valves. But the question is if I can find valves that will fit. It's 24 x 17 mm in size anyway.

 

[carbon]

If you can remove the plastic cage from the back of the valve. I use a knife blade to separate the two halves. Inspect the valve and seat for damage. Possibly the spring has become weak.

 

[DennisCA]

On that one I noted that the seat doesn't seat properly sometimes, like it wants to seat crooked.

I have been looking for check valves but as I feared this particular size does not exist. From china I could order 14x14mm sized check valves. Possibly I could get these to work by machining a 10mm reducing sleeve.

 

[carbon]

If you have one dismantled, take some pictures and add dimensions and I’ll see if there is anything that will fit

 

[DennisCA]

I got it apart but it all looks pretty simple, the spring is kinda weak though. Maybe I'll try and lap the two parts together and see about a new spring.

Piston face still looking good, of course it has barely run:

 

[DennisCA]

"Plunger" is 12.7mm thick and 12mm in diameter. Interesting half an inch exactly there.
The face is 8mm thick and diameter 24mm, center hole is 14mm.
Whole assembly is 24mm diameter and 17mm thick.
Spring is 15mm diameter and length is 8mm and some extra.

 

[carbon]

As a temporary measure you could try stretching the spring a bit and see if that improves how the valve seats

 

[DennisCA]

Doing that, and lapping the mating surfaces on the lathe. Will do all cylinders.

 

[DennisCA]

Took a video, in the video you can't hear the pulsing I do, looks and sounds more steady than it is. I've only managed 3 out of 4 cylinders so far too.

Of course soon after this, the whole front end that the nozzle is attached to came loose from the pipe. Looks like the ring that goes around the pipe came loose from corrosion and the whole thing came of. The ring seals the joint and I think maybe the pipe is expanded at the front so it cannot come off. I tried putting it back after grinding off the corroded end but I think I didn't get the pipe mouth expanded enough as it came loose again.

 

[carbon]

Usually the pipe isn’t flared for these fittings it’s parallel and the nut is secured tightly. The pipe has to protrude beyond the cutting ring before being tightened

 

[DennisCA]

I see, well that matches up with the others, the ring was sitting a bit back, though I wasn't able to remove the ring even if I could move it slightly so I assume there was some slight flaring to retain it.

In this instance I wasn't able to force the ring on any further here, probably needs some sanding down.

 

[Turbo]

I see, well that matches up with the others, the ring was sitting a bit back, though I wasn't able to remove the ring even if I could move it slightly so I assume there was some slight flaring to retain it.

In this instance I wasn't able to force the ring on any further here, probably needs some sanding down.

It works much like a compression ring on a brass plumbing fitting, as you tighten the nut it crimps the ring down on the pipe & also reduces the dia of the pipe slightly where the ring sits, stops it blowing off under pressure. The pipe is not flared, just looks like it is.

Normally the rings are single use, once you've crimped it the internal dia is smaller than the od of the pipe & it cannot usually go back on. You may get away with sanding it slightly so it goes on the pipe. Might be best to anneal the ring before assembling it.

If its a steel ring on a steel pipe grease the threads & tapers before assembly, that will give you a fighting chance of being able to tighten the fitting enough to crimp the ring again, it can take quite a bit of force on the spanners! Sometimes its easier to remove everything & use a vice to hold one half while you swing on the spanner.

BTW I used to install pressure washer pipework in factories & I'm very familiar with fitting steel compression fittings.

 

[DennisCA]

Moving it back on the pipe helped, so far it hasn't come loose. I finally made the last component, an adapter 1/2" BSP to M22x1.5 (Kränzle) and look at that it works!

It feels very powerful, at least as powerful as my my dads old 3-phase Kärcher that he once accidentially removed the paint from the shed with, along with some wood. This one came with a 050 size nozzle however so it's too small, I will look for some 075. But I wanted to test it anyway. I regret buying such a short hose now. But they should be extendable.

In the long run I do think I want to get rid of the metal pipes and manifold, when I set it up rusty water was running out... That's no good.

Replace the hard metal pipes with hydraulic hoses instead, they have been plated but that's broken in places.

I am not sure if aluminium would work for a new manifold though I could possibly have some suitable stainless.

There's the rhythmic vibration mentioned earlier, but it's not noticeable when using the lance, only when it's idling. But I guess the valves will need replacing eventually.

 

[carbon]

Avoid aluminium

 

[carbon]

when I set it up rusty water was running out

If it hasn’t been used for some time then that’s a usual thing to happen.

Replace the hard metal pipes with hydraulic hoses instead

Even these will eventually rust at the ends where the steel fittings are crimped into the flexible hose

 

[DennisCA]

They can't be had with stainless fittings? Or maybe thats €€€ (or £££/$$$ depending)

 

[Guzrik]

They can't be had with stainless fittings? Or maybe thats €€€ (or £££/$$$ depending)

Made my own, could have made it in stainless as well, but I couldn't be arsed and reused the old rusty hosepillars. I have my own but many
agrimechanical oriented companies often have hydraulic hosecrimpers some even in a van. If necessary I would even dare to use a decent hoseclamp for a pressurewasher, pressure is gone the moment it pops off.