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2008 XC90 3.2 HALDEX GEN 3 pump replacement

Help, Advice, Owners' Discussion and DIY Tutorials on Volvo XC90s. The XC90 proved to be very popular, and very good for Volvo's sales numbers, since its introduction in model year 2003 (North America).
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Posts: 4
Joined: Mon Feb 14, 2011 8:14 am
Year and Model: 2008 XC90 3.2
Location: Boulder, CO

2008 XC90 3.2 HALDEX GEN 3 pump replacement

Post by jnormandeau »

I had the dreaded "Anti-Skid Service Required" .
After searching and reading numerous articles and watching videos I got at it.
This is by no means a detailed repair, just a supplement to what I read and watched and what was left out for me.

NOTE: This is when you bring your car in and have the codes read... which I didn't do.

The easiest recommendation was to replace the clock sping. So I bought a used one from a reputable reseller and installed it... did not fix the problem... $125 wasted.....

Brought the car in and the codes indicated it was a faulty AOC pump. (Note: Code read = $65 at indy shop).

It is a pretty straightforward repair.

Parts were $220. I opted for an aftermarket DORMAN pump. The Indy repair wanted $1000 to do the job.

It took me a while to get it repaired. Maybe 4-5 hours over the course of a couple days. Mostly trying to figuring things out, removing rusty parts in awkward positions.... note including time spent getting tools I didn't have to start with.
If I had to do it again it would be a 2 hour job if everything is on hand.

What added to the time was that I followed some instructions on testing the components.
1. You can test the DEM to see if it is putting out voltage
2. you can test the motor to see if it operates while it is still in place
What I found was that the DEM outputted voltage AND the motor works.

So I thought I could get by by just replacing the filter (it was clogged like nobody's business) and fluid thinking it was creating too much strain on the motor and thus blowing the fuse.

Getting the filter replaced was a royal pain in the butt due to its location.
Anyway, after doing all this the fuse still blew.... so time to replace the pump.
NOTE: I wished I spent more time diagnosing the pump. See how much current it drew, etc. This would have saved a lot of time as I would have gone straight into replacing it.

Notes: I backed the SUV on to a pair of car ramps. I uses a floor jack to get the driver side wheel off the ground.

  • Tools that helped that you may not already have:
    Vise-Grip 27 9-Inch Locking Chain Clamp. (best $25 investment for this job)
    24mm Socket
    8mm hex socket (get a spare or two as they can bend/snap)
    Three 8mm x 1.24 x 40 harden steel bolts
    PB blaster
    8" steel punch with a pointed tip
    slide hammer (Oriely auto parts loan center)
    Torque wrench (Oriely auto parts loan center) - need one that goes to 180....
    air tool: impact driver
    RED and BLUE thread locker (don't assume you have some handy, it could be dried up)

Also, the $16 LED work light at HomeDepot are the best....

Lessons learned/suggestions (besides actively maintaining the AOC)

1. It is a pretty straightforward repair.
2. Rusty parts suck and PB blaster is you friend.
3. GEN 3 requires you to remove the prob shaft.
- remove all muffler and center bearing supports
- the tail end muffler support is removed last, slide entire assemble to the passenger side and support it with a milk crate
- tag the flange (sharpie) and drive shaft so you know the orientation when you put it back together
- remove the 6 bolts holding the driveshaft to the flange. (with he car in neutral you can spin the front wheel to rotate the shaft.
- the shaft will most likely be rusted to the flange.
- there are two holes on the back of the flange. Spray PB in to the holes and the other six to get some between the face of the drive shaft and flange. *** Let it sit and do it's job. Preferably over night.***

- Cut one of the bolts to 20mm, insert it into one of the holes in the back and using the punch and hammer gently, but firmly give it a couple wacks. Rotate flange 180 and do the same on the other hole. With patience it will pop free. Wiggle it out and place it to the side above the exhaust pipe.

- Use the chain clamp to secure the flange and have at the nut with the impact wrench and 24mm socket.

- Using 2 8mm bolts and the slide hammer you will be able to get the flange off.
****** BEWARE: oil will start pouring out. Be ready with a pan. This fluid is the worst. ******

- Replace the AOC filter.
- Replace the pump.
- replace the AOC transmission fluid
- Note: by now if you had codes and warning lights they should all go away before you put it all back together.

Good luck!
using the 20mm long bolt
using the 20mm long bolt
Using punch on 20mm long bolt
Using punch on 20mm long bolt
the trusty chain clamp
the trusty chain clamp
Last edited by jnormandeau on Sun Mar 22, 2020 10:23 pm, edited 1 time in total.
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Year and Model: XC90 05-2.5T, 08-V8S
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Re: 2008 XC90 3.2 HALDEX GEN 3 pump replacement

Post by ggleavitt »

While there's no substitute for a VIDA/DICE when you're reading the codes, this link may help someone with troubleshooting in future- https://xemodex.com/us/diagnostic-flow-charts/
2005 2.5T AWD-201k
2008 V8 AWD Sport-132k
Posts: 4
Joined: Mon Feb 14, 2011 8:14 am
Year and Model: 2008 XC90 3.2
Location: Boulder, CO

Re: 2008 XC90 3.2 HALDEX GEN 3 pump replacement

Post by jnormandeau »

^^ Yes. This is how I learned how to test the pump and DEM while it they were still in place. The VIDA said I has a bad pump, but the pump still worked. Lesson learned is to trust the VIDA.....
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