Looking at buying a Lavor Hotbox with issues

[JOEPRO]

Update, 3 hours in now and I just changed the acid again. Black water coming back through almost immediately.



But, its getting cleaner. I checked the fitting in the picture and the bore of it is very well cleaned up but there is still some rust scale visible.

So I'm currently adding all the acid I have left with kettle water again and I'll let it run until 9 or 10pm then flush it all well with clean water to get the acid out.

 

[brightspark]

what is the pressure before trigger pulled and then after its pulled. blocked pipes will keep the pressure up not lower it in use

 

[JOEPRO]

what is the pressure before trigger pulled and then after its pulled. blocked pipes will keep the pressure up not lower it in use

Good point I will do more checking tomorrow. I live in a town and it's dark outside so I'll not fire it up tonight.

I will do flow tests etc tomorrow also just concentrating on getting the coil as clean as I can tonight.

I have used 2.5kg of Citric acid today. I ordered another 5kg there now it is great stuff.

 

[carbon]

what is the pressure before trigger pulled and then after its pulled. blocked pipes will keep the pressure up not lower it in use

As this machine has a syphon injector fitted after the pump the pressure on the gauge even with the nozzle removed from the lance will still be reasonably high due to the restriction in it. It also depends on if the unloader valve that is fitted is flow sensitive or a trapped pressure one.

 

[JOEPRO]

As this machine has a syphon injector fitted after the pump the pressure on the gauge even with the nozzle removed from the lance will still be reasonably high due to the restriction in it. It also depends on if the unloader valve that is fitted is flow sensitive or a trapped pressure one.

I did get more photos of this earlier. There are 2no clear hoses going onto the high pressure parts after the pump and before the coil.

The one with the red arrow on it goes from the detergent tank:




The other one just drops below the machine. Nothing seems to come out of this pipe either maybe its an air inlet of sorts?



Should I disconnect the tank one and blow it through with air to ensure it is clear?

 

[carbon]

The one you have marked as you said is the detergent one and as such will have a restriction inside the pump outlet. The other is a safety device that dumps excess pressure. When operating on hot for long periods the tube in burner coil will store a lot of heat. When you release the trigger and walk away from it the heat in tube still continues to heat the water. As the volume of water is fairly small the extra heat will increase the pressure trapped in the burner coil and hoses. The safety valve should release the excess pressure before damaged the hoses or the burner coil and possibly the thermostat sensor if it’s not externally mounted.

 

[JOEPRO]

Flushing done and its put away for the night. This metal part is on the pump outlet side. It started out like this with about 1 - 2mm thick coating inside:



Now it is completely rust free and clear:



It's discoloured inside but totally clear through. This part was at the very end of my Flushing line so given it is now completely clear it bodes well for the coil itself.

Connecting the mains water to the pump gives a nice clear flow:



It's all well flushed through with clean water and I washed the machine chassis incase some citric acid spilled on it. It definitely benefitted from this, the guys water must be pretty dirty stuff he did live in the middle of nowhere so it could have been well water supply.

I will try it out in the morning, fingers crossed it runs better!

Edit: worth noting also that the PO had said he was using a "£250" quick connect lance and foam cannon etc. In preparation for the sale he had refitted the original Lavor lance. The lance itself looks clean inside. The nozzle at the end was loose so I think he also swapped that over. So in any case I think the lance itself has seen very little use so should be clear.

 

[Turbo]

I removed the original nozzle and the only numbers on it are 15035.

View attachment 430969

I ordered one of the above which with that code comes up as a specific Lavor Missouri part so it's correct for this machine. When I checked it out on ebay it came in below £20 so not too bad.

Those 1/8" nozzles tend to be more expensive than their more common 1/4" cousins.

Looking at a nozzle chart would indicate that an 035 nozzle might be a bit tight for that pump.

https://www.pressure-washing.co.uk/nozzle-chart.php

Your pump puts out 9.5 l/m. To get the 13mpa (130 bar) working pressure the ideal jet size is between a 035 & an 04.
Use a 035 & your working pressure goes up to 150 bar which might overload the motor.
Use an 04 & your working pressure drops to 100 bar.

The 035 might work fine but keep an eye on the pressure gauge. Even better if you have a clamp meter & check the motor amps with the pump going & jet fitted, gauges are not always accurate.

I've converted all my washers to these quick release nozzles.
https://www.ebay.co.uk/itm/272098939181?hash=item3f5a5c512d:g:sZoAAOSwkHxcB7Xy

To use low pressure detergent you'll need this nozzle.
https://www.ebay.co.uk/itm/272102638529?hash=item3f5a94c3c1:g:jbsAAOSwpppcB~uz

Depending on the setup on the end of the lance this adapter should allow you to screw the quick release into where the current jet fits.
https://www.ebay.co.uk/itm/291374162872?hash=item43d740e3b8:g:JqcAAOSwRDpb7Whb

That will give you 5 different nozzles for less than the price of 1 of the original type ones. Ok they will not wear as well as the expensive one but for hobby use they are ok & cheap to replace.

 

[Turbo]

As regards the washer, I'm not familiar with that model. Besides, @carbon has covered most things already. Just a couple of things to check.

When you are checking the flow rate make sure there is detergent in the tank. If the detergent control valve is faulty you could suck in air if the tank is empty.

Check the plastic inlet pipe where the water mains connects to. It's not unknown for them to crack from frost or a knock or leak at the joints, causing an air leak.

A simple one - check to see if there is a pressure adjuster not screwed up fully! It can be missed! It could be part of an external pressure unloader, between the pump & boiler.

If you decide to sell your big washer I'd definitely be interested. I've a couple of interpumps here, I just need a working boiler unit!

If you don't get your new one sorted I could take a look if I call up that way.

 

[carbon]

Looking at a nozzle chart would indicate that an 035 nozzle might be a bit tight for that pump

In some of the charts I have there is listed an 037 which at 130 bar seems to have a flow of 9.6 litres which is a lot closer than the 035.

A simple one - check to see if there is a pressure adjuster not screwed up fully

I’ve been out to a few machines lately that have been down on pressure only to find exactly that problem. But from the pictures it doesn’t seem to have an external pressure control

 

[JOEPRO]

Those 1/8" nozzles tend to be more expensive than their more common 1/4" cousins.

Looking at a nozzle chart would indicate that an 035 nozzle might be a bit tight for that pump.

https://www.pressure-washing.co.uk/nozzle-chart.php

Your pump puts out 9.5 l/m. To get the 13mpa (130 bar) working pressure the ideal jet size is between a 035 & an 04.
Use a 035 & your working pressure goes up to 150 bar which might overload the motor.
Use an 04 & your working pressure drops to 100 bar.

The 035 might work fine but keep an eye on the pressure gauge. Even better if you have a clamp meter & check the motor amps with the pump going & jet fitted, gauges are not always accurate.

I've converted all my washers to these quick release nozzles.
https://www.ebay.co.uk/itm/272098939181?hash=item3f5a5c512d:g:sZoAAOSwkHxcB7Xy

To use low pressure detergent you'll need this nozzle.
https://www.ebay.co.uk/itm/272102638529?hash=item3f5a94c3c1:g:jbsAAOSwpppcB~uz

Depending on the setup on the end of the lance this adapter should allow you to screw the quick release into where the current jet fits.
https://www.ebay.co.uk/itm/291374162872?hash=item43d740e3b8:g:JqcAAOSwRDpb7Whb

That will give you 5 different nozzles for less than the price of 1 of the original type ones. Ok they will not wear as well as the expensive one but for hobby use they are ok & cheap to replace.

That is a great help thank you for that! I was able to cancel the eBay order for the original nozzle so I will order these items you mention they look good.

Unfortunately this morning the washer "feels" better but it's still not right. I made sure the detergent tank was full and carried out a 60 second flow test:



So little not even worth measuring it! Likely about 2 or 3L.

So I think there is nothing else for it now but for me to carefully take the pump apart and see what condition the seals and valves are inside then order a fresh set of replacements. There is a faint rattling sound from the pump at times which could be clogged or faulty valves I guess.

I paid £380 for this washer so I really don't mind if I have to spend a few quid on a fresh set of pump seals for it then with the little use I will be giving it, it should be good for many years.

 

[carbon]

With those pumps the pistons are returned with a spring. These can break and cause problems. But check valves and seals first. With the cylinder head off, try to pull the pistons. If one moves more easily than the rest it likely the spring is broken. You will need to rotate the pump to check each one

 

[carbon]

Does the motor sound like it’s under load when running with the existing nozzle in place?

 

[Turbo]

With the hose off is the flow from the pump steady or pulsing? If pulsing it would indicate that the pump is off a cylinder - stuck valve or piston or bad seals.

 

[JOEPRO]

"Ran when parked"



It appears I have a 1x piston special the others have left the party

 

[JOEPRO]

Upon taking it all apart the castings and pistons are in good condition. There is no damage that I can see apart from the 2x broken springs and the water / oil mix. Pistons are nice and tight and free moving.



Now I need to order up the new springs and seals. That appears difficult enough as I can only find Italian websites who have terrible diagrams and links.

I am glad that I found the real problem though as once I get the parts it should be an easy fix.

 

[carbon]

There must be no damage to the coated part of the pistons for them to be serviceable

 

[carbon]

One of my suppliers list some seals for lavor but they don’t list any models only the dimensions of the seals but no springs.

 

[carbon]

From the state of the oil the pressure seals have given up

 

[roofman]

I call these 5 minute pumps Ok for the sunday morning driveway blast but dont even consider this type of pump for industrial use. My 21L Interpumps and Cat pumps work 8 hours a day non stop sometimes on roof cleans without a single complaint. Look on Ebay for spares or repair Karcher washers, the place is flooded with them and any other pump/motor integral type. If it was me i would put it back together and get it pumping then move it on as "needs looking at" type of sale.