Peugeot 508 RXH HYBRID4 De-airing

[Alex CaraYman]

Hi everyone, I have changed the rear reducer (differential) on my 508 RXH, now I have to do the airing on the cooling system, and I was told that there are like 4 or 5 points where to bleed the system, 2 under the hood, 1 on the electric motor and one on the inverter.
Has anyone done this before? or does anyone know the steps to take to bleed the entire cooling system?
Thank you.
Peugeot 508 RXH - VF3**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

Sorry, can't help you with this as work on the traction battery system requires special training given the nature of these things.

[mr-white]

Yes done it a few times remove the oil filter pipe and engine cover, you will see a bleed nipple on top of the alternator, crack this open, take cap off just keep filling the header tank with normal water until all air has been pumped out then add coolant.
There is one on the motor but we didn't bleed it from there

To be fair the hybrid cooling system runs off the main water system so would bleed itself, back to the expansion tank, as long as you kept an eye on the water level.

Bleed it whilst running and in 4x4 mode as this ensures the hybrid water pump stays active.

You can also activate the hybrid water pump in actuator test in either hcu1 or hcu2 ecus in diagbox

Hope this helps

[Selbis1]

Thnx. What about air bleeding spot on rear electric differential?

[impaelas]

Did you manage to do this? I've bled 3 valves in the engine bay (thermostat, radiator/alternator and heatcore).
Apparently there's one in the back of the car on the electric drive. Mine is overheating now...

[Doom]

I bleed whole system a few days ago after I fixed rear differential. To do it properly you need diagnostic tool. You should start electric water pomp, open bleeder on the electric motor and inverter one by one, when you see water you should close it. Once done you should be good. I did it with open cooling reservoir under the hood. You shouldn't drive with air on the system, inverter could damage. I spoke with guy who is fixing only 508 rhx and DS5, he said that this is main reason or damaging inverter - don't bleed correctly after differential change or water pump replacement (mechanical or electric). When you replace rear differential remember to clean everything really carefully. Metal pieces from old broken differential will damage new one.

[impaelas]

For the life of me I cannot find inverter bleeding valve. is there any chance it's under the battery from the inside of the car? I only have two lines IN/OUT.

It just got back from Peugeot center with no avail. They know less than I do...

P.S. How much did the differential change set you back if I may ask?

[Doom]

Sorry I made a mistake, one bleeding point is on the electric motor, second on the battery not inverter, my bad.

In my case cost was minor, I fixed broken differential on my own. Issue was caused by one of the bearings that broke, it's always the same bearing, I received 2 additional broken rear differentials from local workshop. All 3 were damaged exactly the same way. Fix is cheap but time consuming. Original parts costs 25Eur + sealant and oil. Full cost was ca 50Eur. But it took 2 days to clean all metal pieces attached to the electro magnetic clutch . The reason why they break is lack of the oil change.

[impaelas]

thank you!

would you mind terribly taking a photo of it? Dealership is at it for two days now and I got a replacement car to drive.
Bu any chance do you have schematic or part numbers for the differential? I'll have to do it myself as they won't repair, only replace with new one and quoted 2.150eur for the part alone.

Again, thank you!

[Doom]

I have differential parts on my desk, I can make some photos and explain you what's wrong, how to fix it. If you want to do it on your own it's possible but you have to have good manual skills and tools to remove bearings. It would be better if you wait till tomorrow. I left full differential in my country house.

You will need:
1. Bearings removal tool,
2. cleaner - break cleaner is ok, IPA or other pure alcohol will be also ok,
3. paper towel,
4. Sealant - I used Loctite 5980
5. Metal tweezers and strong magnet
6. A lot of time and patience
7. 2x FAG 6009C3 bearings
8. 2x FAG 6207C3 bearings

These bearings are used in the original differential. In my case they lasted 409k km - quite long. That's why I used the same parts.

Long story short:
Inside differential you have 2 gears and electromagnetic clutch attached to one of them. In all cases that I saw, broken was one of the bearings (because oil was not changed). You have to take this differential apart, clean it very well and replace bearings - that's it

If you don't feel too confident to do it on your own, You should be able to ask workshop that is rebuilding gearboxes to do this work for you. Most of them are doing exactly the same everyday with gearboxes. But you have to tell them to clean electromagnetic clutch really well - this is most important.

My way is to clean everything using break cleaner from oil, then most of the metal pieces will fall off, only these one on electromagnetic clutch will stay. To clean them I'm using twizzers with strong magnet attached - then metal pieces are attaching to the twizzers and I can remove them from clutch. I will provide you some photos soon. You can also contact me via PM if you need.

[impaelas]

i have no words. thank you. beer is on me.

[Doom]

Differential contains 2 gears:

1. Electromagnetic Clutch - bearings are already removed:

2. Reduction gear - it's between electric motor and electromagnetic clutch:

Reduction gear is easy to clean. Problem is with Electromagnetic clutch - there are tones of metal pieces

Here are parts of electromagnetic clutch:

1. Electromagnet and twizzers with strong magnet attached:

Metal pieces removed from electromagnet:

Clutch with gear:

Copper ring that is placed between clutch and electromagnet:

You have to take differential apart, remove bearings and clean everything very well. There are plenty of metal pieces (metal powder) in electromagnet and clutch. You have to remove as much as you can, if you see even one metal splinter you have to remove it. It can attach between electromagnet and clutch and clutch will not be able to work properly.

I'll make more photos later. Missing are: both cases, sensors, spacers. Tomorrow morning I'll mount new bearings. I'm heating bearings ( to 120C) in the oven and freeze whole night gears in the freezer. This way I can just mount them together without hammering bearings - IMO it's even better than hydraulic press. I can put them in place by hands.

[Doom]

Part 2:

This is full differential with electromagnet adapter and clutch position sensor:

Adapter:

Clutch position sensor

First view when you open the cover:

Same:

Cover itself:

Bottom cover with spacers:

Small gear:

Here you see issue, broken bearing that was smashed:

Bigger gear with electromagnet, clutch and a lot of metal pieces:

Bottom side of the bigger gear:

Here you see a lot of metal pieces between clutch and electromagnet.

I'll add comments once I'll back home.

[Doom]

Guide:

When you start removing electromagnet adapter and clutch position sensor you cannot use any tools, plastic is fragile, you should remove them by hands, pull and wiggle.

You can use pry bar to separate covers but you shouldn't use any tools to remove gears - you can remove them by hands. They are fit in the covers without too much space, if you pull them strait and evenly it will be easy. Usually I pull first a few millimeters, then second and so on. You can't remove only one, they are overlapping.

When you mount gears to the case, there is whole in the electromagnet that have to go to the pin in the housing.

[impaelas]

So after two PSA shops gave up I did it myself with BSG vacuum pump kit (130eur on ebay).
I would like to thank @doom once again for all the help and ideas. You know more than licenced mechanics!