What is the seal on the pipe going into the back of the power steering pump

MS5931 IS THE ONLY FLUID THAT CAN BE USED FOR THE POWER STEERING SYSTEM. NO EXCEPTIONS!

Important note: The factory fill power steering fluid for all 1999-2004 Grand Cherokees is a unique fluid, MS5931. ATF+4 (MS9602) should not be mixed or used as a “topping off” fluid on the Grand Cherokee WJ. All WJ models should be serviced using ONLY the special MS5931 fluid. ATF+4 is NOT an approved Power Steering Fluid and should never be used under any circumstances. Note that all fluids will darken in color with usage and fluid color is no longer an indication of fluid condition.
The 'foaming' you describe is almost certainly air getting into the system. The power steering pump will cause a suction effect in the pump and then pressurize the system. Look for loose hose clips, damaged piping, and leaking seals on the pump body between the pump and its fluid reservoir

There may or may not be a ororinon the hoses but regardless it in itself will not cause any moaning. Low fluid from the oring leaking or a pump going bad will make a noise. Now there are orings inside sealing the pump inside the reservoir tank. I guess it is possible for them to make a noise.

it should be in as new condition
there is a special method of fitting power steering hoses and if the procedure as per the manual is not followed ,then has every possibility of leaking
best take it to an accredited power steering shop and have it done correctly

If the fuel is leaking into the car you will need the replace the seal on the top on the pump assembly not the seals on the pump itself but before changing the seal just double check the fuel lines are tight and the leak is actually from the fuel splashing out of the tank. The seal your after is referred to as the pump assembly oring ( big rubber oring around the top of the assembly a smear of silcone can be used as a temporary fix but erge you to get it fix properly as soon as possible and fuel fumes in the cabin can be extremely deadly)
Hope this helps

M62 ENGINE TURN OFF RADIO FIRST. YOU NEED TO INSTALL A MEMORY SAVER BEFORE DISCONNECTING NEGATIVE BATTERY CABLE. TO KEEP FROM LOSING PCM MEMORY. TO REMOVE OIL PUMP.YOU NEED TO LOWER OIL PAN.REMOVE THE LEFT AND RIGHT ENGINE MOUNTS AT THE BOTTOM.REMOVE POWER STEERING PUMP AT THE HOLDER.REMOVE OIL PIPES AT THE POWER STEERING PUMP ALSO ON AUTOMATIC TRANSMISSION, REMOVE BANJO BOLT FOR THE OIL RETURN PIPE FROM THE OIL FILTER AT THE OIL PAN.REMOVE THE MOUNTING BOLT ON THE SPROCKET FOR THE OIL PUMP AND REMOVE THE SPROCKET ALONG WITH THE CHAIN,REMOVE 3 OIL PUMP MOUNTING BOLTS AND REMOVE THE OIL PUMP.REMOVE THE OIL PIPES OUT OF THE CRANKCASE. BEFORE INSTALLING NEW OIL PUMP, CHECK SEALS ON THE OIL PIPES AND REPLACE IF IT NECESSARY.LUBRICATE THE SEALS WITH OIL AND THE OIL PIPES.CHECK THE SEAL IN THE OIL PUMP AND REPLACE IF NECESSARY, SCREW THE HEXAGON ADAPTER BACK INTO THE OIL PUMP UNTIL IT STOPS.INSTALL OIL PUMP AND 2 RIGHT SIDE OIL PUMP MOUNTING BOLTS .TORQUE BOLTS 14 - 17 FT LBS. POSITION THE CHAIN ON THE PUMP AND SPROCKET AND INSTALL THE SPROCKET.TORQUE BOLT TO 35 FT LBS VERIFY THAT THE CHAIN IS POSITION CORRECTLY. ADJUST THE CHAIN SAG TO 0.315 - 0.472 INCHES 8 - 12MM BY TURNING THE HEXAGON ADAPTER IN THE OIL PUMP, THEN INSTALL THE LEFT SIDE MOUNTING BOLT. INSTALL OR CONNECT THE FOLLOWING. INSTALL BANJO BOLT FOR THE OIL RETURN PIPE FROM THE OIL FILTER AT THE OIL PAN, INSTALL THE POWER STEERING PUMP AND CONNECT THE OIL LINES IF EQUIPPED.INSTALL LOWER OIL PAN, INSTALL THE ENGINE OIL.INSTALL THE NEGATIVE BATTERY.

Go to your local parts Auto Zone and they should be able to print you up one ,,,if not your local Ford dealership will have a parts counter and they will print you one for sure.

the main one is the feed which is pressurised and the main cause is the flexible rubber pipe ,they perish and go porous ,take this pipe off and have the rubber part replaced in a hydraulic type place that does industrial type work ,might cost 20 euros if that

You can do one of two things: the easiest of the two is to replace the p/s pump assembly with a reman unit.
The other way is to install a pump reseal kit. you'll have to dissasemble the pump to install a series o-rings and the front pump seal. This can be quite difficult. I recommend getting a service manual to help you with this process.

what year? what engine?

Installation

1. NOTE: If a new power steering pump is to be installed, the unions that are supplied fitted to the pump should be removed and saved for future use.
   Using the special tool, install a new O-ring seal.
   1. Push the new O-ring seal onto the special tool.
   1. Locate the tool over the union and ease the O-ring seal onto the union.

Before you replace the pump, check the filter located inside the oil tank. This filter cleans the oil before going to pump. REMEMBER that Audi uses a special oil!!! Not your normal power steering fluid! Mixing them could cause damage to the entire system!