Medium
30-60 minutes
Genuine Karcher replacement part, this item is sold individually.
The purpose of the Grooved Ring is to keep the oil in the pump and the water from mixing together.
The piston does move through this part.
This is a wear part, it will need to be replaced ASAP once it is worn.
Oil Sealing 12x20x4/6 6.365-393.0
OEM part for: Karcher
Part Number: 6.365-393.0
$5.49
In Stock
Ships within 1 business day 
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Product Description ?
- Dimension: 12 X 20 X 4/6
- Classification: Part
- Weight: 0.01 lbs.
- Also Known As: Groover Ring, Oil Seal, Stopper Lip
- Shipping: Ships Worldwide
Frequently Purchased Together ?
Compatibility
This Oil Sealing 12x20x4/6 will fit the following 149 machines. Confirm this part works with your model, and view the detailed model diagrams and repair help we have to offer.
Karcher
Show More Compatible ModelsThis item works with the following types of products:
- Pressure Washer Parts
Repair Videos ?
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Oil Sealing 12x20x4/6
Customer Part Reviews ?
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The oil seals were a little more challenging than the water seals. I found the best way to remove them, wish to get a nail with a thin head and put that in the gap between the seal in the the case and tap them out. They were not going to be pulled out.
Parts were as ordered fit perfectly.
Guest -
April 10, 2023
Verified Purchase
OIL seal for Karcher pressure washer
Arrived quickly. Did not install it.
Guest -
June 12, 2020
Verified Purchase
Online repair video was invaluable.
Karcher pressure washer pump was leaking oil. Reviewed the online repair videos. Was able to determine what parts I needed. Trouble free ordering and delivery process. All parts were a perfect match for those that needed replacing. Even though the video was for a slightly different model pump, it was so well done that I was able to replace a seal set that was not even mentioned in the video. Tip: The new split seal O-rings appear to be too large for their openings but that is the design. They need to be compressed to fit into the seat. This takes a bit of finesses and a bit of elbow grease, but slow and easy does it. My 12-year-old pressure washer is now working like new and has no oil leaks.
Guest -
April 15, 2020
Verified Purchase
Worked as expected
Arrived quickly
Mike -
July 15, 2019
Verified Purchase
Perfect fit
Seal matches perfectly
Guest -
April 30, 2019
Verified Purchase
Received these parts but haven't had a chance to work on the power washer
No comment at this time.
Guest -
December 29, 2023
Verified Purchase
Correct part.
Parts were fine, shipping was expensive for such a small light item.
Guest -
September 24, 2019
Verified Purchase
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Customer Repair Instructions ?
All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part.
Leaking
Renee - July 16, 2016
👍 3 of 3 people found this instruction helpful
Tool Type
Pressure Washer
Difficulty
Easy
Time
Less than 15 minutes
Tools Used
, None
Changed a few o-rings and everything is fine now.
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Pressure washer pressure pulsing very fast with high pressure
William - August 22, 2017
👍 1 of 1 people found this instruction helpful
Tool Type
Pressure Washer
Difficulty
Medium
Time
More than 2 hours
Tools Used
Screwdriver, Pliers, Socket set, Wrench Set
1. Purchased all most likely parts likely to cause problem: valves, seals & springs.
2. Disassembled pump. No oil in wobble plate housing - only some water. (Probably piston seal?)
3. Cleaned housings, reused parts with carb cleaner. Added 15-40w oil. Reassembled & installed.
4. Works better than when I bought it, (was rebuilt unit.)
5. I found seals a little tricky to install as they are flared out & you'll probably try to use a screwdriver to install - careful, easy to damage seal.
6.Also, check the spill valve before you remove pump - it can cause erratic (as well as low) pressure.
2. Disassembled pump. No oil in wobble plate housing - only some water. (Probably piston seal?)
3. Cleaned housings, reused parts with carb cleaner. Added 15-40w oil. Reassembled & installed.
4. Works better than when I bought it, (was rebuilt unit.)
5. I found seals a little tricky to install as they are flared out & you'll probably try to use a screwdriver to install - careful, easy to damage seal.
6.Also, check the spill valve before you remove pump - it can cause erratic (as well as low) pressure.
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Water leak
carlos - July 14, 2016
👍 2 of 3 people found this instruction helpful
Tool Type
Pressure Washer
Difficulty
Medium
Time
30-60 minutes
Tools Used
Screwdriver, Wrench Set
1. Disassemble pump
2. Inspect pieces and parts
3. Found some seals broken and dried
4. Order the parts
5. Clean and put the new spare parts per diagrams and videos
6. ensemble pump per pictures and hand sketches
7. Put new oil pump
8. Test pressure washer
2. Inspect pieces and parts
3. Found some seals broken and dried
4. Order the parts
5. Clean and put the new spare parts per diagrams and videos
6. ensemble pump per pictures and hand sketches
7. Put new oil pump
8. Test pressure washer
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Unit was leaking oil and pulsating when spraying.
David - August 20, 2023
Tool Type
Pressure Washer
Difficulty
Easy
Time
15-30 minutes
Tools Used
Screwdriver, Socket set
Took unit apart. Replaced bad parts and re-installed.
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Karcher G 2650 HH pressure washer leaking water between the two bronze plates (piston guidance and cylinder head) on the pump. Pressure washer was also pulsating.
William - May 24, 2023
Tool Type
Pressure Washer
Difficulty
Medium
Time
1-2 hours
Tools Used
Socket set
1 Break the cylinder head bolts (do not loosen or remove the bolts since pump oil will leak out)
2 Remove the bolts attaching the pump to the engine.
3 Slide the pump off the keyed engine shaft.
4 Place the pump upright and remove the cylinder head bolts.
5 Separate the two bronze plates (piston guidance and cylinder head)
6 I replaced the three "grooved rings" and the three oil seals. One of the "grooved rings" was obviously damaged and is presumably the cause of the water leaking. I thought this was the most difficult part of the job. The seals are pretty tight and putting the new ones in also requires patience. Removing the oil seals was assisted by a small weep hole on the back side of the piston guidance plate. I poked a small nail thru these weep holes that helped pop-out the oil seals. The new oil seals went in fairly easily. The "grooved rings" were easy to remove but difficult to install the new ones. Had to squeeze the edges to get the seals in which took some effort.
7 I changed the pump oil. The old oil had a milky appearance which I assume is due to some water mixing. Be sure to hold down the wobble (swash) plate as you tip the pump casing to drain the oil. There are ball bearings under the wobble (swash) plate that might dislodge from its retainer plate. The new oil (Karcher 10-40) was clear and looked like normal engine oil.
8 Reassemble the two bronze plates and place them on the pump casing. Note that pressure springs provide resistance and so you have to press the reassembled plates pretty hard as you reinsert the cylinder head bolts. Tighten the bolts so the oil doesn't leak out during reassembly.
9 Slide the reassembled pump on to the keyed engine shaft and tighten the pump mounting bolts. Snug up the cylinder head bolts. I put some grease on the engine shaft first.
10 The repair was successful. No leaks and no pressure pulsations. (Note that I had replaced the overload valve previously which had no effect on the pressure pulsations). In retrospect I would also replace the large o-ring between the pump casing and the piston guidance plate.
2 Remove the bolts attaching the pump to the engine.
3 Slide the pump off the keyed engine shaft.
4 Place the pump upright and remove the cylinder head bolts.
5 Separate the two bronze plates (piston guidance and cylinder head)
6 I replaced the three "grooved rings" and the three oil seals. One of the "grooved rings" was obviously damaged and is presumably the cause of the water leaking. I thought this was the most difficult part of the job. The seals are pretty tight and putting the new ones in also requires patience. Removing the oil seals was assisted by a small weep hole on the back side of the piston guidance plate. I poked a small nail thru these weep holes that helped pop-out the oil seals. The new oil seals went in fairly easily. The "grooved rings" were easy to remove but difficult to install the new ones. Had to squeeze the edges to get the seals in which took some effort.
7 I changed the pump oil. The old oil had a milky appearance which I assume is due to some water mixing. Be sure to hold down the wobble (swash) plate as you tip the pump casing to drain the oil. There are ball bearings under the wobble (swash) plate that might dislodge from its retainer plate. The new oil (Karcher 10-40) was clear and looked like normal engine oil.
8 Reassemble the two bronze plates and place them on the pump casing. Note that pressure springs provide resistance and so you have to press the reassembled plates pretty hard as you reinsert the cylinder head bolts. Tighten the bolts so the oil doesn't leak out during reassembly.
9 Slide the reassembled pump on to the keyed engine shaft and tighten the pump mounting bolts. Snug up the cylinder head bolts. I put some grease on the engine shaft first.
10 The repair was successful. No leaks and no pressure pulsations. (Note that I had replaced the overload valve previously which had no effect on the pressure pulsations). In retrospect I would also replace the large o-ring between the pump casing and the piston guidance plate.
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Pressure washer (Model 2650HH) was spewing out water between halves of valve housing
Daniel - May 4, 2023
Tool Type
Pressure Washer
Difficulty
Medium
Time
1-2 hours
Tools Used
Screwdriver, Pliers, Socket set, Adjustable Wrench, torx #30
1) watched several (multiple times) You Tube videos to understand the inside workings.
2) worked at removing the Actuation Housing. I realized that the key was probably rusted, and with some lubricant removed the housing.
3) Had to get Karcher USA to email me the owners manual and parts lists. (very timely/responsive).
4) three different orders placed, after realizing parts needed replaced.
5) Did not understand when replacing shaft seals (pt no 6.365.393.0) if the groove was to be oriented up or down.
6) Same thing for groove ring (pt no 6.365.394.0)
7) Assembled with new parts, but water still spews out between the 2 housing halves.
8) Water mixed with oil is still present. I will need to disassemble, clean, and consider other part replacement. The PW worked fine with wand activation at the startup, but the water side seems to be leaking into the oil reservoir and forcing oil out. I was surprised to see behind the swash plate (wobble plate). May have to disassemble the to place the seal ring (pt no 7.367-018.0).
2) worked at removing the Actuation Housing. I realized that the key was probably rusted, and with some lubricant removed the housing.
3) Had to get Karcher USA to email me the owners manual and parts lists. (very timely/responsive).
4) three different orders placed, after realizing parts needed replaced.
5) Did not understand when replacing shaft seals (pt no 6.365.393.0) if the groove was to be oriented up or down.
6) Same thing for groove ring (pt no 6.365.394.0)
7) Assembled with new parts, but water still spews out between the 2 housing halves.
8) Water mixed with oil is still present. I will need to disassemble, clean, and consider other part replacement. The PW worked fine with wand activation at the startup, but the water side seems to be leaking into the oil reservoir and forcing oil out. I was surprised to see behind the swash plate (wobble plate). May have to disassemble the to place the seal ring (pt no 7.367-018.0).
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Pump was leaking oil
Thomas - April 22, 2023
Tool Type
Pressure Washer
Difficulty
Medium
Time
30-60 minutes
Tools Used
Socket set, Wrench Set
Followed your YouTube repair video to every detail. After re-assembly powered up pressure washer and the pump still leaked oil.
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rapid pulsation
arthur - June 26, 2020
Tool Type
Pressure Washer
Difficulty
Medium
Time
1-2 hours
Tools Used
Screwdriver, Wrench Set
found 1 bad check valve
replaced all 3 check valves
replaced all 3 oil seal rings
replaced all 3 grooved rings (lip side out using a small screwdriver to get it in)
cleaned swash plate and bearings
put new oil (karcher 15 w 40 )
reassembled
cleaned and lubed unloader valve
replaced all 3 check valves
replaced all 3 oil seal rings
replaced all 3 grooved rings (lip side out using a small screwdriver to get it in)
cleaned swash plate and bearings
put new oil (karcher 15 w 40 )
reassembled
cleaned and lubed unloader valve
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water leaks from pump
joel - May 11, 2019
Tool Type
Pressure Washer
Difficulty
Medium
Time
1-2 hours
Tools Used
Socket set
Invert pressure washer and remove four bolts (there's oil in the upper section to lube the bearings)
Split the pump halves and replace the seals.
Reassemble the halves and reinstall the pump to the bottom of the engine (ensure the upper section of the pump is still about 3/4 full of motor oil).
Snug up the four pump bolts.
Turn pressure washer right side up and allow time for the engine oil to drain back into the lower engine.
Connect water hose, pressure wand, and turn on the water.
Start engine (it may smoke a lot for a few minutes) and check for water leaks. Mine dripped some for the first few minutes then stopped after running the washer.
Split the pump halves and replace the seals.
Reassemble the halves and reinstall the pump to the bottom of the engine (ensure the upper section of the pump is still about 3/4 full of motor oil).
Snug up the four pump bolts.
Turn pressure washer right side up and allow time for the engine oil to drain back into the lower engine.
Connect water hose, pressure wand, and turn on the water.
Start engine (it may smoke a lot for a few minutes) and check for water leaks. Mine dripped some for the first few minutes then stopped after running the washer.
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I had fluctuating pressure. It would run fine for several seconds that the pressure would drop significantly.
Theodore - July 29, 2017
Tool Type
Pressure Washer
Difficulty
Easy
Time
1-2 hours
Tools Used
Socket set, Wrench Set
I rebuilt the pump with the parts you suggested. Be careful with Karcher pumps. If you replace the nozzles with standard big box store nozzles they can cause this surging. That is what I recently did. Make sure you have the correct capacity nozzles before you rebuild a pump.
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All our customer repair instructions are solicited directly from other customers just like you who have purchased and replaced this exact part. While we moderate these reviews for profanity, offensive language or personally identifiable information, these reviews are posted exactly as submitted and no alterations are made by our team.
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