Check your Haldex pump people...

[Trevor M]

Kevin; I do not have a full answer to your question, but the initial running of the Haldex pump from VCDS is to 'push out' the filter to aid removal. I do not see why this can not be done by starting the engine, as I believe the pump should run initially. However, the procedure also involves running the pump for a period from VCDS after changing the filter and oil, presumably to avoid air locks in the system. I do not know if this is essential, but I have read somewhere on this forum (maybe further up this thread,) where someone thought their Haldex engagement was 'jumpy' after the service, but had not run the pump with VCDS afterwards.

[KevinGill]

Thanks so much for the prompt response Trevor M, the cynic in me suspects that if I go to a service centre, they will charge me for a ‘Haldex Service’ but may just change the oil and not replace the filter. I suspect it’s impossible to know unless I stand there and watch (which I’m guessing they won’t allow). It’s a tricky one. If the VCDS is not critical to the procedure then I would like to do it myself. Again, many thanks 😉

[ejstubbs]

6 hours ago, Tech1e said:

However the stability system has to recognise wheel slip before the Haldex is engaged?

 

My understanding (based on little more than past threads on here, and very possibly incorrect) is that the Haldex is always engaged a little bit i.e. there is always a small percentage of drive going to the rear wheels.  Even if that's not the case, it's still my understanding that Haldex is a gradual system: it doesn't suddenly dump 50% of engine torque to the back end, it feeds it in as required.  So it's a bit misleading to talk about it being "engaged" as if it were an on/off thing.

 

From my reading the of the user manual, TCS/ESC is something that gets involved when the on-board sensors indicate that intervention above and beyond the normal operation of the car is required (AIUI TCS reduces throttle input in response to wheelspin while ESC brakes individual wheels if the car's attitude becomes unstable).   The Haldex doing its thing is normal, so although it may use the same sensors as TCS e.g. for wheelspin (which AIUI is detected for the purposes of the Haldex within a fraction of a revolution of the driving wheels), the Haldex sending drive to the rear is not an intervention by the TCS so the light on the dashboard doesn't come on.  (If it did then, in certain road conditions, it would be flickering on and off practically all the time.)

 

Basically: TCS only gets involved if redirecting torque via the Haldex doesn't cure the wheelspin.

 

Stands by to be shot down in flames...

[muddyboots]

6 hours ago, Tech1e said:

 

However the stability system has to recognise wheel slip before the Haldex is engaged?

Not necessarily, the Gen 4 Haldex does pre-empt slip by engaging when you pull away from standstill and also under harder acceleration (even if no wheel slip is detected).

There's some info on it in the self-study guide.

 

[KevinGill]

Hello to the Haldex-interested. I quizzed my local service centre today as to exactly what they do when they undertake a service on a Gen 4; it was an interesting response; ie: 'we just drop the oil and then replenish it'. So I asked; 'what about the filter?' They said that they never replace the filter as its a waste of time. Is this correct?

[kenfowler3966]

It’s not correct but you won’t get Skoda to admit that.

Once filter blocks life expectancy is very limited and changing oil does not help.

Even the latest ones without the replaceable filter should be opened and the mesh screen cleaned

[KevinGill]

Thanks Ken, the price of the filter here is a crazy $160 AUD but I suspect it’s a cost I will have to bear in order to avoid premature wear/damage. The main problem for me is the lack of a VCDS but I suspect I might be able to do the job without one.

[kenfowler3966]

Even just cleaning and reusing the filter would be better than soloey replacing the oil. Indeed the Haldex 5 has been modified with a built in filter that just needs clearing of debris.

 

Could you not source one abroad and posted to you. I can't believe a small scree filter should cost very much? Not sure how much $160 is in real money terms!!

[KevinGill]

Thanks again Ken, $160 AUD is pretty close to 90 GBP. I will look overseas but as you can imagine, postage becomes a factor.

Do you think its possible to clean a used Gen 4 filter? Regardless, I will keep researching and keep briskoda abreast of any solutions I find 😉

[idleness]

6 hours ago, KevinGill said:

Thanks again Ken, $160 AUD is pretty close to 90 GBP. I will look overseas but as you can imagine, postage becomes a factor.

Do you think its possible to clean a used Gen 4 filter? Regardless, I will keep researching and keep briskoda abreast of any solutions I find 😉

Mine has been cleaned twice according to the garage, I will change it next time.

[GerrardUK]

So, I have only just got around to this (a few months' later than planned...) and I am having trouble with geting the connector off. It probably didn't help that access was a bit tight as I was doing it under a trolley jack. I couldn't feel the what I assumed to be the latch moving at all. I am not sure if it is a 2 stage connector (although why it would be, I don't know) but it's probably more likely just filled with crap?

 

I also thought about removing the whole control panel thing it was on but it seemed again annoying that I couldn't quite get a socket or spanner on the lower 10mm head in order to at least maybe rotate it.

 

And even if I do get it disconnected, looks like I am going to have mess around with the clipping points. Shame I don't have access to an inspection pit or 4-poster as that would no doubt make life easier!

[jonbenj]

I’ve been off this week and plucked up the courage to do my rear discs and pads, and the Haldex drain and clean. I found this guys video really helpful, along with the other info on this thread. 

https://youtu.be/CqvRLbwT7yY

 

My cars now on 64000 miles. The Haldex was done by the dealer once, I think about 40000miles but obviously the screen in the pump was never changed. 

I had the car up on axle stands at the back, and access was awkward but not too bad (unlike the rear calliper carrier bolts🤬). 

Quote

On 15/10/2019 at 21:53, GerrardUK said:

I am having trouble with geting the connector off. It probably didn't help that access was a bit tight as I was doing it under a trolley jack. I couldn't feel the what I assumed to be the latch moving at all.

 

Like the previous poster, the harness connector was tight but came off ok with perseverance. As the tech in the video I’ve linked says, it helps to push the clip in first and then you can ping it off with your finger. If you have a look under your bonnet you might see the same style of connector on the back of your headlights that you can practice on. 

[GerrardUK]

Thanks for the link to the video. Turns out you have to push the whole connector in first and then use the clip to release. I've had my car serviced and oil changed now (mainly for the service history) so will wait a while before attempting it again.

[Bingodalton]

On many forums I was reading about cleaning Haldex Pump Gen 5 and guessing about O-ring size.
What is strange that even those that have changed O-rings did not measured or wrote their dimensions. One guy even made a picture of both o-rings where you can see difference in size, but no dimension, just guessing and some info from adds on ebay. Like nobody wants to help.

 

I have bought 8 sizes with inner diameter from 39mm to 46mm, 2.5mm thickness, so we will see which one suits best. Will measure them.

[widdershins]

Did you find out which size was correct?  I'm looking to get my haldex done soon, so doing my homework just now.

[Martinb100]

This Gen 5 service kit is a bit expensive but problem solved on O ring sizes etc. Good customer service from supplier, very helpful on phone, with any queries. https://www.awesomegti.com/genuine-vw-haldex-gen-5-service-kit/

Edited 13 June, 2020 by Martinb100
Insert extra detail

[rover220]

Contact matt at haldex repairs based in Crewe. He's very helpful with info and stocks the necessary spares. 

[Sno_monsta]

I was just looking on Haldex Repairs.

 

Pretty sure I have a blocked filter. Skoda dealer serviced the Haldex last year and the fault still shows on my Carista. TBH I only got the Carista when my engine took a dump.

Anyway Skoda don't have the Haldex filter, Gen 4 listed as a spare part, even though it shows it on the schematic. So all the y did was change the oil for £69.

I'll probably buy filter and oil and see if the pump is still OK.

[Sno_monsta]

https://www.haldexrepairs.co.uk/shop/filters/generation-gen-4-filter-kit-vw-audi-seat-skoda/

 

 

[idleness]

On 15/06/2020 at 19:56, Sno_monsta said:

I'll probably buy filter and oil and see if the pump is still OK.

If its a fault showing on Carista its 99% certain the pump has gone.

Don't ask me how I know this.........twice 😞

Luckily first one was done under warranty but they didn't change the filter only cleaned it......... 😞

 

 

[Sno_monsta]

I've been quoted £470 to replace the pump and another £160 to fit and service the system.

 

I think I'll buy the pump kit and do it myself. There's a set of ramps I can use or do you think I'll need an inspection pit?

[idleness]

22 minutes ago, Sno_monsta said:

I've been quoted £470 to replace the pump and another £160 to fit and service the system.

 

I think I'll buy the pump kit and do it myself. There's a set of ramps I can use or do you think I'll need an inspection pit?

That seems expensive to me. First one was £350 or so in 2017 second one was £451 inc vat last November, new pump, filter fitted and oil.

 

Edited 16 June, 2020 by idleness

[Sno_monsta]

5 minutes ago, idleness said:

That seems expensive to me. First one was £350 or so in 2017 second one was £451 inc vat last November, new pump, filter fitted and oil.

 

 

The whole kit from Haldex Repair is £240ish. 

 

As soon as I know the status with my engine repair I might just order that.

 

https://www.haldexrepairs.co.uk/shop/repair-and-service-kits/gen-4-vw-audi-seat-skoda-haldex-pump-kit-0ay598549a/

[idleness]

If DIY you will need VCDS or similar to run the pump, can't remember whether its to get the pump out or sort the oil level when its in. plus top up the oil once its done.

[J.R.]

I may have screwed my diff bearings through making a stupid mistake with the drain plugs, so I have a couple of saved E-bay listings of complete diff assemblies with Gen 5 Haldex pump & controller included and they were all around the £250-300 mark inc delivery.

 

If the pump alone is that price it might be worth looking around, buying a complete unit using what you need & selling on the rest, you would still need the oil though, I re-used the old O rings, its easy to judge if they are serviceable, parts not so easy to find here and delivery costs can be prohibitive, if they had been damaged I probably have the right sizes amongst my stock of random O rings otherwise I have a splice tool for made to measure ones.