Hi all
The Superb Mk3 AWD is fitted with a 5th generation Haldex. Regarding VAG Group, and Skoda in particular, it also equips: Octavia 3, Superb 2, Karoq, Kodiaq.
It may also apply to Scala and Kamiq, unless they're equipped with 6th generation. I actually don't know for these latter.
Since I have limited trust in garages in my neighborhood and because I like 'DIYing' on my car, I've decided to change the oil of my Haldex system on my own.
If one follows Skoda recommendations, workshop manuals (see cardiagn.com) only mention a simple oil replacement every 3 years and that's it!
But when you start diving into documentations or in youtube videos about 5th gen Haldex, you can notice that the oil pump has an intern strainer, which trends to get really dirty, whereas it's never cleaned !
Hence, here is this humble tutorial ! I apologize, if there are any vocabulary issues... I'm French.
Firstly, here are all elements, that we're going to look at:
#13 : Bleeder screw (M10x30) - P/N N 910 827 01 (tightening torque 38 Nm for Superb Mk3, but on other VAG model it may be 32Nm - Have a look to the workshop manual corresponding to your car. See cardiagn.com)
#14 : Filler screw (M10x1x10) - P/N N 902 818 02 (tightening torque 15 Nm)
#3 : Retaining screw (M6X35) for the Haldex Control Unit - P/N N 105 540 05 (tightening torque 9,5 Nm)
#11 : Retaining screw (M6X35) for the Haldex hydraulic pump - P/N N 105 540 05 (tightening torque 9,5 Nm)
#9 : O-rings for the pump - P/N 0CQ 598 305 (⚠️Note : This P/N is a kit, which includes both O-rings, but also both retaining screw #11! Don't by these screws twice!)
Gear Oil :
According to ifinterface.com:
P/N G 065 175 A2
or
According to what dealer sold me:
P/N G 60 175 A2 - 850 ml (~29.9 fl oz)
By the way, don't forget to check that the oil can actually contains 850ml through the gauge on the side of the can. Indeed, just for the short story, the oil can I had bought only contained 750ml, though brand new and still crimped . I had to go back to the dealer to exchange the oil can.
The requested volume for the maintenance operation is usually around 700-720 ml (24.6-25.3 fl oz), thus it leaves little room for error (and even less if the can is not filled correctly).
The total bill was ~75 € for all parts (without screws #3, which you don't need to change).
- Difficulty : 2
- Time needed : 1h30 approx.
- Number of person needed : 1
- Necessary tools :
¤ Screws #3 and #11 : Torx T30 or 10mm Hex socket, if you don't have Torx
¤ Screw #13 : 8mm Hex
¤ Screw #14 : 5 mm Hex
¤ For Hydraulic pump strainer screws : Torx T10
¤ Ratchet or classic wrenches for disassembly
¤ Torque wrench(es) to apply specified torques: (9,5 / 15 / 38 Nm)
¤ Short and intermediate extensions for ratchet or torque wrenches to enable easier access to screws
¤ A small flat screwdriver
¤ Oil drip tray
¤ Rags
¤ 1 wooden toothpick
¤ Lifting means
¤ Syringe for oil filling
Dealing with the syringe, I've bought this one for 20-25€ on Amazon. It makes the job perfectly!
Step #0 : Preparation
You need to lift the car high enough to get under the car and to get enough space to move your arms comfortably. In my case, 370mm (~14.5") of ground clearance were enough.
Note: Though you've lifted the car, it needs to remain horizontal to make a proper filling with right oil level (see step 5).
If this case, I had to compensate the natural slope of the ground.
Step #1 : Oil draining
Start with the filler screw (#14 / blue square) removal for more safety. Indeed, if it's stuck, you won't be "snooked", with a completely empty Haldex oil tank and no way to refill it.
Once you've removed the filler screw. Don't get rid of it immediately. You'll need it again temporarily for Step #4!
Now, you can remove the bleeder screw (#13 / red circle).
There's no difficulty to remove these 2 screws.
There are 2 good news for this step:
- The drain screw is long enough, so that you won't get surprised, when the thread gets totally disengaged from the housing.
- Even if the drain screw has an horizontal axis, there's only a small quantity of oil, and since it is very fluid, it flows well vertically from the edge of the hole. Little chance of getting trapped with the oil, which flows suddenly and farther than the drip tray. Phew!
However, it takes several minutes to really let all the oil drain:
Step #2 : Hydraulic pump removal
Whereas oil is still dripping, start removing 2 retaining screws (#3) for the Haldex Control Unit. They are quite easy to access with a small 1/4'" ratchet.
After that, you can rotate the Haldex Control Unit, to bring the connectors on the top upside down. This simple operation will help you saving a huuuuuuge amount of time ! But this tip is explained / told nowhere!!! Otherwise, you will have to disconnect the pump connector 'blind'... And if you do this operation for the first time, You hardly understand how to proceed. Decency leads me to shut up the time that I spent trying to remove this µ%£$@&# connector before I changed my mind on the operating process.
Pump connector before Control Unit removal :
Once the 2 retaining screws of the Control Unit have been removed, you can easily access to the connector:
Now simply insert a small screwdriver in the notch (red circle) and push in the arrow direction. Very simple...
Then, you need to unclip the black plastic wire protection, which keeps the pump wiring away from the propeller shaft. It's clipped in 2 locations on each side of the shaft,
You just need to pinch the 2 lugs at their end to make them go back through the hole in the housing.
Left side (Control Unit side) :
The upper red circle in the mirror shows what you hardly see in the lower dotted circle... It's clearly the circled part, that has to be pinched and then pushed/pulled in the arrow direction.
Right side (pump side), just proceed the same way :
The pump wire is now fully free. You can now remove the 2 retaining screws (#11) of the hydraulic pump (#10). Very easy too.
Warning from this point, it will be 'Apocalypse pump' ! Please keep children and sensitive souls away from following pictures!
Pull in the pump axis direction, while rotating it around its axis in one direction and then the other to ease the removal. Be very careful, when the pump is about to get out completely, not to strike the contact surface of the housing, nor to strike the pump strainer. FYI, the strainer is not sold alone. It's sold with the pump, which approximately costs 180-200 € (w/o VAT) !
And there, under your dumbfounded eyes , here is the sinister spectacle that awaits you:
A strainer almost entirely clogged with sh**t!
And the pump housing is not even better...
FYI, this Haldex is only 2.5 years old and has only 45000 km (~28000 mi) on the clock. And considering the way I use my car, I don't think the Haldex faces a heavy duty use.
Therefore, as I already mentioned somewhere on this forum, one can only notice that the oil replacement process in the maintenance manual for the Haldex 5th generation is clearly incomplete !
By the way, look at this video below from ~28 mn, you'll see the impact of the strainer cleaning on the pump demand signal ... It's clearly a proof that w/o a strainer cleaning, the pump unnecessarily faces severe conditions and that sooner or latter there's a risk of pump failure...
Step #3 : Pump cleaning and reassembly
Since the pump is now removed, you need to remove the strainer. Use a Torx T10 for both screws:
Then wipe the pump dry with a rag, being careful not to get the dirt into the ports.
Fort the strainer, a cleaning with some white spirit and a soft paintbrush. But be careful, not to brush to hard to avoid tearing the strainer mesh, which is very thin!!! Eventually, a simple soaking in a small glass of white wine ... sorry , I mean... White Spirit should help removing most of the dirt and finishing finely with the paintbrush.
Let the strainer dry, while you remove both O-rings around the pump, using a wooden toothpick as a lever. It will avoid hurting the grooves.
You can now, clean the area between both grooves with white spirit.
Once everything is clean, you can mount the strainer back onto the pump. Be careful ⚠️ ! I didn't find any information about their tightening torque.
Thus be sure to tighten enough to firmly place the strainer on the pump body (to make a good seal against dirt), but not too hard to avoid risks of cracking the plastic. Shall I remind you the price of the pump, just in case ?!?
Now, pour some drops of fresh oil in a small container. By the way, FYI :
Haldex used Oil 2.5 years old & 28000 mi on the clock / Haldex fresh oil
Put few oil drops on both O-rings to lubricate them and install them onto the pump. Keep using the wooden toothpick if needed.
The pump is now ready to be mounted back onto the car :
Now, you can clean the housing with rags before putting the pump back in place:
Don't forget the bearing surface, where the threads of the retaining screws are located. Here you can see some dirt left, that I removed right after taking the picture...
You can now put the pump back into the housing. Be careful, not to pinch both O-rings .
Once there's only 5-6mm (1/5 -1/4") between bearing surfaces of the pump and the housing, it gets a bit harder to push in by hand. This is probably caused by O-rings, which may act as a slight "bead" to efficiently seal. You now realize how clever it is, to lubricate both O-rings to prevent them from rolling inside out and to make this operation even more difficult.
When the pump stops into the housing, you can put 2 retaining screws back in place (#3 - tightening torque = 9,5 mm)
Put the black palstic pump wire protection in the correction position and clip it into both holes. Be careful, you still work 'blind' (unless you have a small mirror) .
Reconnect the pump connector on the Haldex Control Unit and rotate the Haldex in its normal position. Watch out to rotate the Control Unit in the correct direction not to twist unnecessarily the pump wire.
Put both retaining screws to fix the control unit (#3 - tightening torque = 9,5 Nm). For the lower screw, the propeller shaft flector is slightly in the way and leads you to put the bit with a small angle. But you can still manage to have enough grip with the bit to tighten.
You can now install the new bleeder screw (#13 - tightening torque = 38 Nm).
Step #4 : Oil filling
According to the workshop manual, the filling shall be performed with an oil temperature between 20°C and 40°C (68°F / 104°F). If the ambient temperature is to low, put the oil can in a bucket filled with hot water for a while to bring the oil at the right temperature.
You can now inject fresh oil in the filling hole (see blue square, on the 5th picture) with the syringe. You have to fill with oil, until it overflows. This should be approximately 650ml (~22 fl oz).
Put the OLD filler screw back in place temporarily and tight it slightly. Yes, you've been told to keep it upon removal at step #1! Do you remember? !
Etape 5 : Oil level adjustment and ending
Start the engine and let it run for ~1mn, to let the hydraulic pump fill with oil correctly.
Shut the engine down, then remove the old filler screw again (#14 / still the blue square on the 5th picture ).
Top up with oil until it overflows again, and you can put the new filler screw to finalize the operation (#14 - tightening torque 15 Nm).
That's it!
Fresh oil! Clean pump strainer! Happy Skoda owner! ... You can put the car back onto the floor now !
Now it's up to you!