As promised: Changing the electrohydraulic roof pump!

[DMcCook]

Thanks.
ive been doing similar searches for weeks and I’ve seen lots of pictures of the pump, but don’t recall seeing details of an extra switch to operate the pump.

 

[TripleBee]

Small update:

It looks like I found the reason why my roof lowered wonky. The emergency hydraulic pressure reliever for emergency roof lowering wasn't as tight as it had to be.

I tightened the screw, and now the roof closes even again. Now I can't "shake" the roof anymore, pushing the oil from the left side to the right and back.

I haven't had the time to test the roof's ability to stay up for more than 24 hours without having the need to pump the roof up again, but I have full confidence that it will be alright now.

 

[aidanic]

Thanks for the useful thread and pictures... some beginner questions following an emergency roof closure...

A friend has a 2015 T5 with the electrohydraulic roof. It apparently got jammed in the open position, and the roadside rescue used the bleed screw to close the roof to get the 50 miles home. (What Velcro?) I looked at it yesterday.

Should we be able to lift the roof manually? Just pushing it up? We managed to raise it about 6 inches, although it appeared hugely heavy and maybe we were pushing against the hydraulics.

If we get the roof up, is there a recommended order of checking things - disassembling the cabin looks to be only if we're changing the pump. I'd like to verify all the simple stuff first.

Is it even possible to lower/raise the roof manually?

Thanks in advance - Aidan

 

[hamed]

Anyone have old damged pump? I can try to repare it with local workshop. My company is responsible for many pump, GT, ST and blower design and we have experience with this type of equipment.

Hiya, i have a 2008 California which has a leak from this bolt. Wondering if anyone knows the issue and repair suggestion. Thanks

 

[sidepod]

So when you tried tightening it I assume it didn’t stop leaking?

 

[hamed]

Some more pictures of the pump.

Still in the California with all the hydraulic tubes attached.
View attachment 54911
The left bottom an most right top tube ar for the right ram/piston, the other two are for the left ram/piston.
I released the pressure first (with roof closed) by turning the bottom center srew, near the thumb. Then I took out the bottom left and top left tube. No oil was spilling out. Then I unscrewed the top right screw, near the yellow dot. By turning loose, there was still some pressure in the tubes, so they popped out, but were held by the not yet completely loosened screw. Saved me some prying like the other two. So I guess those two top right tubes are filled with the oil for lowering the roof, meaning, oil is pushed on the side of the piston/ram.

On this pump I will have to check everything that has to do with the tube on the top left position. This is the pushing up side of the cylinder(?). If there is an internal leak, then the pressure drops on the pushing side, making the roof sag at that side.

All the parts of the valves I will have to research:
View attachment 54913 View attachment 54914 View attachment 54915
View attachment 54916

Plugs for the tubes
View attachment 54917

View attachment 54912

I have some oil leak from the centre nut next to the thump when is fully tighten. Is there a seal inside that might need changing. The roof works fine but after sometime need to refill the oil because of the leakage

 

[hamed]

So when you tried tightening it I assume it didn’t stop leaking?

Correct, still leaking. Pump works fine though but oil needs topping up because of the leakage. Trying to take the bolt out to see if there is washer that needs changing, not easy as the bolt is secured with a tiny pin

 

[hamed]

So when you tried tightening it I assume it didn’t stop leaking?

 

[sidepod]

Does that pin (or grub screw?) gave a hex head to it? Not easy to tell from the pic.

 

[hamed]

Does that pin (or grub screw?) gave a hex head to it? Not easy to tell from the pic.

It seems the only way is to drill it, which is not easy. Wondering if the there is O ring that might gone bad inside, i think that bolt is for pressure release but is it just to release air or oil as well?

 

[WelshGas]

It seems the only way is to drill it, which is not easy. Wondering if the there is O ring that might gone bad inside, i think that bolt is for pressure release but is it just to release air or oil as well?

Is it not the Manual Release to lower the roof if it fails in the Up position, as described in the Handbook.
When used in an emergency I've never heard of it leaking hydraulic fluid.

 

[WelshGas]

It seems the only way is to drill it, which is not easy. Wondering if the there is O ring that might gone bad inside, i think that bolt is for pressure release but is it just to release air or oil as well?

This might help.

Official factory blueprints or internal engineering drawings for the Volkswagen California electro-hydraulic roof pump (VW Part Number: 7H7875791 / 7H7959705A) are proprietary and not publicly published by Volkswagen. However, comprehensive technical system overviews, fluid routing schematics, and community-sourced reverse-engineered block models provide the exact information needed for diagnosis and rebuilds. [1, 2]

️ Official System Diagram & Layout
The fundamental layout of the electro-hydraulic system is documented in Volkswagen's Self-Study Programme (SSP 329): Volkswagen Motorhome California 2004. [1]

• The Core Unit: Located centrally above the front cabin headlining, the assembly integrates a 12V electric motor, a dual-direction hydraulic gear pump, an oil reservoir, and an integrated valve manifold block. [1, 2]
• Actuation Lines: Two high-pressure hydraulic lines route from the central pump manifold across the roof structure directly to the left and right hydraulic rams (cylinders). [1, 2]
• Control Feedback: The system relies on senders (microswitches) integrated into the roof hydraulics to communicate "roof open" and "roof closed" status back to the central camper operating panel. [1, 2]

Reverse-Engineered Manifold Drawings
Because original valve schematics are kept private by the OEM manufacturer (Power-Packer), members of the VW California Owners Club have mapped the manifold block using 3D CAD modeling. [1, 2]

• The Manifold Circuit: The pump operates on a dual-path circuit where reversing the electric motor's polarity switches the fluid direction to either extend (raise) or retract (lower) the roof. [1]
• Emergency Release Screw: Located directly on the pump block, this manual bypass valve drops system pressure, allowing fluid to return to the reservoir so the roof can be manually lowered in a power failure. [1]
• Internal Failure Points: Flow errors, unbalanced lifting, or "sagging" are usually caused by degrading internal O-rings or check valves inside the drilled channels of the manifold block, rather than a failure of the electric motor itself. [1, 2]

 

[hamed]

This might help.

Official factory blueprints or internal engineering drawings for the Volkswagen California electro-hydraulic roof pump (VW Part Number: 7H7875791 / 7H7959705A) are proprietary and not publicly published by Volkswagen. However, comprehensive technical system overviews, fluid routing schematics, and community-sourced reverse-engineered block models provide the exact information needed for diagnosis and rebuilds. [1, 2]

️ Official System Diagram & Layout
The fundamental layout of the electro-hydraulic system is documented in Volkswagen's Self-Study Programme (SSP 329): Volkswagen Motorhome California 2004. [1]

• The Core Unit: Located centrally above the front cabin headlining, the assembly integrates a 12V electric motor, a dual-direction hydraulic gear pump, an oil reservoir, and an integrated valve manifold block. [1, 2]
• Actuation Lines: Two high-pressure hydraulic lines route from the central pump manifold across the roof structure directly to the left and right hydraulic rams (cylinders). [1, 2]
• Control Feedback: The system relies on senders (microswitches) integrated into the roof hydraulics to communicate "roof open" and "roof closed" status back to the central camper operating panel. [1, 2]

Reverse-Engineered Manifold Drawings
Because original valve schematics are kept private by the OEM manufacturer (Power-Packer), members of the VW California Owners Club have mapped the manifold block using 3D CAD modeling. [1, 2]

• The Manifold Circuit: The pump operates on a dual-path circuit where reversing the electric motor's polarity switches the fluid direction to either extend (raise) or retract (lower) the roof. [1]
• Emergency Release Screw: Located directly on the pump block, this manual bypass valve drops system pressure, allowing fluid to return to the reservoir so the roof can be manually lowered in a power failure. [1]
• Internal Failure Points: Flow errors, unbalanced lifting, or "sagging" are usually caused by degrading internal O-rings or check valves inside the drilled channels of the manifold block, rather than a failure of the electric motor itself. [1, 2]

Thank you, my guess is also a failed o ring, problem is getting the screw out

 

[hamed]

This might help.

Official factory blueprints or internal engineering drawings for the Volkswagen California electro-hydraulic roof pump (VW Part Number: 7H7875791 / 7H7959705A) are proprietary and not publicly published by Volkswagen. However, comprehensive technical system overviews, fluid routing schematics, and community-sourced reverse-engineered block models provide the exact information needed for diagnosis and rebuilds. [1, 2]

️ Official System Diagram & Layout
The fundamental layout of the electro-hydraulic system is documented in Volkswagen's Self-Study Programme (SSP 329): Volkswagen Motorhome California 2004. [1]

• The Core Unit: Located centrally above the front cabin headlining, the assembly integrates a 12V electric motor, a dual-direction hydraulic gear pump, an oil reservoir, and an integrated valve manifold block. [1, 2]
• Actuation Lines: Two high-pressure hydraulic lines route from the central pump manifold across the roof structure directly to the left and right hydraulic rams (cylinders). [1, 2]
• Control Feedback: The system relies on senders (microswitches) integrated into the roof hydraulics to communicate "roof open" and "roof closed" status back to the central camper operating panel. [1, 2]

Reverse-Engineered Manifold Drawings
Because original valve schematics are kept private by the OEM manufacturer (Power-Packer), members of the VW California Owners Club have mapped the manifold block using 3D CAD modeling. [1, 2]

• The Manifold Circuit: The pump operates on a dual-path circuit where reversing the electric motor's polarity switches the fluid direction to either extend (raise) or retract (lower) the roof. [1]
• Emergency Release Screw: Located directly on the pump block, this manual bypass valve drops system pressure, allowing fluid to return to the reservoir so the roof can be manually lowered in a power failure. [1]
• Internal Failure Points: Flow errors, unbalanced lifting, or "sagging" are usually caused by degrading internal O-rings or check valves inside the drilled channels of the manifold block, rather than a failure of the electric motor itself. [1, 2]

Failed O rings on the pressure release screw

 

[WelshGas]

Failed O rings on the pressure release screw

View attachment 148714

How did you get it out?

 

[hamed]

How did you get it out?

Just gave it to local machine shop, I think they drilled out the pin. O Rings are hard and falling a part