Air in fuel lines

[merc convert]

Less than 12 months after having all the seals changed in my C250TD I am suffering againg from air in the fuel lines. You can see the fuel run back when switching the engine off. After speaking to my reliable Indy garage he has informed me the seals are no longer available from MB and the lines should be replaced.

1. Does anyone know where the "o" rings can be purchased?

2. Is there anything he could have missed? 11 rings changed last time.

 

[simon_wall69]

Changing the lines is not a great deal more hassle than changing the o rings and the lines aren't massively expensive.

Does your car have a fuel tank strainer, as this could be getting blocked creating the vacuum to pull the fuel back down the lines, this happened on my w123.

 

[merc convert]

Simon where would the strainer be?

 

[simon_wall69]

Mines as the fuel line comes out the tank. The nearest line to the fuel filler cap. Yours could be different though.

 

[robs-mbz]

I just had the same problem on my E300TD, fuel running back down the feed pipe to the filter (engine stopped) and air bubbles (while the engine is running) in the suction fuel line from the filter to the injection pump. Not wanting to strip off the manifold to change every seal I worked out that the leaking seal had to be the connection on the suction line from the filter to the injection pump. My local dealer had the O rings in stock but it was not much more expensive to buy the complete tube (£6.41 inc VAT!). Fitting the new part completely cured the problem.

 

[angry]

little bit fiddly but take your time remove inlet manifold (replace oil seals )change all pipes as they go brittle . also change o ring in unit on block above fuel pump (mb parts man will know what i mean) approx cost of parts from 60.00 quid and 2.5hours taking ones time

 

[merc convert]

Well my indie has had the car for more than a week rechanged all seals and the tank sender and now cannot start the car, seems it is airlocked. Has any got any advice.

 

[Bolide]

Just keep turning it over till it fires. It'll go in the end

Some people seem to make heavy weather of this problem. There is a finite number of places air can leak in - deal with them all and the problem will go away. If it doesn't go away you've missed one

Nick Froome
www.w124.co.uk

 

[SilverSaloon]

if you can measure one of the existing o-rings then just buy some aftermarket ones. Viton ones ideally.

this is what i did.

 

[merc convert]

After 9 days it is back and cured. All seals changed, a couple of fuel lines, coldstart valve and tank sender unit. It had to be a process of elimination starting with the cheapest parts replaced first. Now - £260