2.7 CRD fuel leak at high pressure pump

[OffroadSpike]

I ended up buying a remanufactured HPFP from Germany, tested before shipping with a Bosch test bench. Replaced it and easy enough the car fired and working again.

Originally Posted by JoergM

Since we are looking at fuel lines here. I want to change my fuel filter from stock to one with a primer pump since the CRD does not really have one, I think it is one for a Toyota Hilux. I got this tip from a CRD driver back in Melbourne. Had this filter for ages on my bench but did not think to install it ever, until now since i am working in that area anyway.

Now the outlets of the new filter are a bit different compared to the stock. for the fuel in I am not worried since it is a regular rubber fuel hose which I can replace if I have to, but for the outlet it is pointing downwards and I wonder if I can replace the clear fuel lines with a good OEM part which is more flexible. The stock ones seem to be really stiff. Not sure if this supposed to be like this or if it is just age and the diesel fuel cause them to become inflexible.

I wouldn't bother to replace all that. The car is "easy" to prime when everything is working as it should, adding an electric fuel pump to lift the fuel from the tank won't fix the bubbles in the fuel lines, it's just masking a pre-existing problem.

The fuel hoses on the 2.7 CRD are stiff and not easy to bend, they are shapped like that so they easily fit through the designed empty spaces. Fuel lines are usualy not a problem unless they are cracked, the problem is in the orings on each end, replacement is cheap and easy.

If you still have probems with bubbles/air in the lines, the problem should be in the fuel filter. I just replaced mine for a MAHLE ORIGINAL KL 188 because I was having water in fuel sensor problems (no actual water inside the filter), which got corrected after changing the filter (it may have been a bad connection or faulty filter). This filter comes with new orings except for the water in fuel sensor, you MUST REPLACE this oring, I was also having bubble problems on top of the fuel filter hose, the oring on the sensor was flattened and didn't look in good condition. I'm having no bubbles after replacing this oring.



Just a tip to prime the car after replacing the fuel filter. Buy yourself a hand pump like pic related:



Unscrew the bleed plug on top of the fuel filter. Fit output hose of the hand pump in the bent pipe on top of the filter, this is the entry inlet from the tank. Place the other end hose in a diesel container and pump the diesel inside the filter until you see it pouring out the bleed plug. Close the plug and connect the hoses. It should take a lot less time to prime (around 20 seconds) contrary to the up to 2 minutes some Mercedes Sprinter guys tell if you don't fill the fuel filter (and could actually wear injectors and fuel pump from lack of lubrication)

[MuzzaWA]

My solution was to simply install the inline bulb pump inline permanently upstream of the filter...

[JoergM]

Originally Posted by MuzzaWA

My solution was to simply install the inline bulb pump inline permanently upstream of the filter...

Not a bad idea. However, I had the new fuel filter for ages (was one of the first things I bought) in my garage already and I have a primer pump on my W123 which just works great. And my Fuel system was already hacked and the return line did not go into the filter but straight to the return line.

So I might have done a bit too much but now I know I have a properly working fuel system and I do not need to worry about air bubbles in the fuel lines anymore.