Kranzle pressure washer oil

[julianf]

At £40 a hit (x3) plus the seal kit, I'd start getting a bit bothered then. But, sure, if they're knackered, my dislike of their cost won't change them.

Will see what becomes of it.

 

[Turbo]

As carbon said, if the oil is milky you have piston or seal problem.
If it is overfilled that suggests that quite a lot of water has made its way into the piston housing.

If the low pressure seals are gone you will usually see water dripping under the pump but not if the drain holes are gunged up.

Some washers are prone to making the oil milky due to a poor seal design. The old KEW 3 piston pump was like this. You could fit new seals and pistons and in a few weeks the oil was white again!

But Kränzle is a good quality pump and it shouldn't happen under normal use.

It's not hard to take off the cylinder head and have a look at the pistons and seals.

A common cause of damaged seals is running the pump dry or leaving it running on bypass too long, the water gets hot as it circulates inside the pump and quickly damages the seals.

 

[jo1010]

Definitely not milky here either. Run your cheap oil and see if you still get the problem...
(Btw ours used mainly for agri trailers and the odd chassis clean - too powerful to let anywhere near 'nice' vehicle paintwork )
The pumps are great to work on - v well made with maintenance needs in mind

 

[Turbo]

As regards oil. I used do the service work for a Karcher main dealer.
All we ever used was a good quality mineral oil, 15/40 engine oil for single phase machines, EP90 for 3 phase. It was usually mobil or shell branded.
Some of the small hobby grade machines with sealed gearboxes used a light hydraulic oil, maybe 22 or 27 grade.

 

[julianf]

As carbon said, if the oil is milky you have piston or seal problem.
If it is overfilled that suggests that quite a lot of water has made its way into the piston housing.

If the low pressure seals are gone you will usually see water dripping under the pump but not if the drain holes are gunged up.

Some washers are prone to making the oil milky due to a poor seal design. The old KEW 3 piston pump was like this. You could fit new seals and pistons and in a few weeks the oil was white again!

But Kränzle is a good quality pump and it shouldn't happen under normal use.

It's not hard to take off the cylinder head and have a look at the pistons and seals.

A common cause of damaged seals is running the pump dry or leaving it running on bypass too long, the water gets hot as it circulates inside the pump and quickly damages the seals.

The unit seems to be a 2021 build -

I assume that's what the 07-2021 means?

It's got a pressure switch on it, so won't have been running on bypass, but may have been run dry.

They tried to deliver the oil today, but I've been out all day so no further progress.

 

[carbon]

For me always run with it connected to mains water or at least flooded suction don't expect it to suck water from below the pump. The slower motor speed versions are better at sucking water

 

[carbon]

If the pistons are ok, when fitting the seals install them into the cylinder head. Do not install them on the piston and replace the cylinder head.
Had one company deliver a machine to me after they replaced the seals and couldn't get it to work. There fitter got irate with me when I started to take the pump apart to find the fault, claiming that he'd fitted new seals and it made no difference. He'd fitted the seals on the pistons then refitted the cylinder head which cut every seal inside into at least two parts, shame he missed the crack in the back of the cylinder head due to frost damage. So seals alone were never going to sort that pump out

 

[Turbo]

If the pistons are ok, when fitting the seals install them into the cylinder head. Do not install them on the piston and replace the cylinder head.
Had one company deliver a machine to me after they replaced the seals and couldn't get it to work. There fitter got irate with me when I started to take the pump apart to find the fault, claiming that he'd fitted new seals and it made no difference. He'd fitted the seals on the pistons then refitted the cylinder head which cut every seal inside into at least two parts, shame he missed the crack in the back of the cylinder head due to frost damage. So seals alone were never going to sort that pump out

An ex car mechanic came to work with us servicing. He always fitted seals in backwards with the lip facing out of the head away from the pressure because they were easier to fit that way.
That was one of the many cock ups he did and wouldn't listen to anyone else when told the correct way to do things. Eventually the boss let Seamus go.
They did work for a while that way but eventually failed prematurely. We were regularly coming across seals fitted backwards for months afterwards and we called it doing a Seamus!

 

[hooblah]

I scored an older model for £20. I noticed that the oil was milky so I changed the seals and filled it with engine oil. The oil was still milky.

 

[carbon]

Unless you dismantle the pump completely its very difficult to drain all the contaminated oil, usually if I encounter a pump that has this problem I'll change the oil at least twice rather than dismantle the pump especially if I'm working on site as its quicker to change the oil than dismantle a pump.

 

[julianf]

The oil turned up earlier.

I drained the old and refilled. It went milky-ish instantly and hasn't got much worse since.

I guess I'll run it for an hour or so and then change it again and see what's what.

Im tempered to take the front off it and "have a look" but, unless you have experience, you never really know how much ware on parts is acceptable.

I mean, I could look at the pistons and they're not going to look brand new, as it's 5 years old, but I, personally, won't know what's an acceptable level of ware and what's too much.

And, as someone (probably) said, replacing seals on a worn face often just ends up in chewed seals.

So, yeah, I'll run it a while and then change the oil again and see what happens then.

 

[carbon]

Definitely run it for a bit to warm the oil up then change it after a short time whilst it’s still warm

 

[carbon]

Any wear on the sides of the pistons will damage the seals. For me there is no acceptable amount of wear, but I’m charging for my service and don’t want to have to go back and repair a pump a second time for nothing. But I also don’t want to charge for parts that are not required. I have to buy valves kits for a complete pump so usually six valves per kit. If one breaks I’ll replace just one or two if required and charge accordingly rather than fit the complete kit

 

[Turbo]

The oil turned up earlier.

I drained the old and refilled. It went milky-ish instantly and hasn't got much worse since.

I guess I'll run it for an hour or so and then change it again and see what's what.

Im tempered to take the front off it and "have a look" but, unless you have experience, you never really know how much ware on parts is acceptable.

I mean, I could look at the pistons and they're not going to look brand new, as it's 5 years old, but I, personally, won't know what's an acceptable level of ware and what's too much.

And, as someone (probably) said, replacing seals on a worn face often just ends up in chewed seals.

So, yeah, I'll run it a while and then change the oil again and see what happens then.

The piston will usually be chrome plated steel or solid stainless steel or ceramic sleeves on a steel centre.

They don't really wear out but the plated ones can get chips in the chrome plating which will be fairly obvious.

The stainless ones can get scored along their length, again fairly obvious though it rarely happens. If you can feel the scoring with your fingernail you need to replace them.

The ceramic ones are the hardest wearing and there is only 1 reason you would ever need to change them. If the pump freezes it will often crack the ceramic sleeve and the damage will again be obvious plus the water will be running out underneath the pump.

 

[carbon]

The stainless ones can get scored along their length, again fairly obvious though it rarely happens

Used to see that a lot possibly 30 years ago, some looked like there were spined shaft’s.

 

[carbon]

The piston will usually be chrome plated steel or solid stainless steel or ceramic sleeves on a steel centre.

The kranzle ones have a thin black ceramic coating maybe 0.5 mm thick that can chip some of the karchers have a very similar piston. But I have seen some more recent karcher’s without the coating again.

 

[Turbo]

The kranzle ones have a thin black ceramic coating maybe 0.5 mm thick that can chip some of the karchers have a very similar piston. But I have seen some more recent karcher’s without the coating again.

It's hard to beat the thick ceramic sleeves used on commercial grade Karcher and Interpumps.

 

[julianf]

update -

I changed the oil again, and i dont think the stuff i put in was much better than the original, so i figured it was time to take a look.


The gap between the motor and pump was full of, i assume, old emulsified oil, or hard water deposit or something - just junk.

The pistons are discoloured, but i can neither see nor feel any other defects on them at all -

The carriers were fairly jammed in with more of the white grime. Similarly they are discoloured but seem ok -

I dont think anyone has ever been in there before.


I cleaned it up and put it back together again, and now, sure enough, there is dripping from the gap between the motor and pump.



Again, the pistons are discoloured, but i could really find no surface defects (i realise that fitting new seals to ropey pistons is false economy) -

Can someone who knows more than me confirm that this is just a seal kit job?

Thank you.

 

[Turbo]

Hard to tell but the coating may be worn off the pistons. Try polishing them with metal polish to see if the hard chrome is still there.

Was there high pressure seals stuck in the cylinder head? This is the main one to check. Take it out and check how tight a fit it is on the piston. It should be a tight sliding fit. If loose you need seals.

The low pressure or suction seals are inside the carriers and should also be a sliding fit.

The position of the small holes on the carriers can be important. On the old Karcher pumps they have to be uppermost otherwise the pump doesn't work properly.
The position of the holes varies between pump brands.
The hole is normally to let out water that leaks past the hp seal. It needs to be kept clear.

 

[julianf]

edit - ive just watched the video again, and, no, i did not take the hp seal out

Im watching this video -

snip -

I removed all the seals, apart from the last one on the motor side (which is just a flat washer)

I get the impression that the the bits that do the work are in the brass carrier -

The one i left in would be #33.

I think its probably #32 that does most of the work?

In the videos ive watched, #31 seems to be hard to get in/out of the brass carrier. I could just slide it in by hand, without effort.

But, whatever - i know the seals are stuffed, its just a question of the pistons really, BUT...

Looking at the video i just linked to, ive spotted something that i had not noticed before -

The pistons in that one are discolored similarly. And, i think, the chap says he is demonstrating with a brand new machine.


The thing is all back together again now, and ill need to be using it until whatever parts im ordering turn up. Im somwhat reluctant to pull it apart again to do further tests, but i will if i have to.

I put the carriers with the holes at 12/6 oclock. Im not sure what they were at when i took it apart.