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CE 230 on LPG;SLK 230COMP;Nissan Z 300TT
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3 Posts
Discussion Starter #1
Hi merkypeeps. This is my virgin first query, but a biggie.

I have a recurring petrol leak from my pump. It has been repaired twice using new washers, but keeps coming back. The symptoms are unusual ( to me at least).
1. Leak from front of pump.

2. Have also had overflowing from charcoal filter in wing into engine bay.

3. Re-start when hot often problematic, as if not enough juice getting through.

NB car was converted to LPG some years ago, using a smaller petrol tank. Works fine tho apart from this leak, and switches between the two systems fine.

Questions:

1.Is there a pressure relief valve somewhere which is causing an over-pressurisation of the petrol system?

2.Why would the charcoal filter overflow? Never had this on any car before.

3.Could the smaller tank be the problem, increasing the pressure INTO the pump and thus the system, and causing the higher level of petrol pressure/washer / union failure?

My wife is now refusing to travel in the car due to the constant pong... my view is that it won't go boom just yet as the leak into the undertray and engine bay is sporadic and not near the exhaust!!!!!

I am baffled by this one. Any helpers out there who've experienced similar leaks/pressurisation of systems????
 

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2008 E320 Bluetec, 1988 560SL totalled unto death). 1997 Dodge Ram 1500, 1983 300CD
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1,342 Posts
Assuming the washers

(actually gaskets) were the right size and of the correct copper material, the leak can be from a cracked banjo fitting. The fitting can be cracked or distorted by overtightening, possibly in frustration at trying to stop the leak.

Pull it apart once more and carefully inspect the banjo fitting and the mating fuel pump surface. Reassemble with NEW gaskets and tighten firmly. If new copper gaskets are not available, the old ones can be annealed by heating to red hot on your kitched stove, then cooling slowly.

You my also want to inspect the fuel hose where it is swaged or clamped to the banjo fitting. If anything looks hinky, replace hoses and fittings. May be due anyway at that car's age.

BTW, change your charcoal canister and yes, there are check valves at the output end of your fuel pump but they are unlikely to cause this problem.
 

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CE 230 on LPG;SLK 230COMP;Nissan Z 300TT
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Discussion Starter #4
Many thanks for that. I think the pump's fine - it's a new one.

Another chap has suggested a cracked bajo link - will get the garage to take a look, and replace the charcoal fliter while they're at it.

Kind regards

RM
 

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CE 230 on LPG;SLK 230COMP;Nissan Z 300TT
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3 Posts
Discussion Starter #5
Thanks.

Think I'll vote for the banjo connection!

Will take it back to the garage next week and ask them to do it all again... for the third time.

Also going to buy a new tank cap just in case it's that plus the leak filling the car with fumes, as the boot stinks too.
 
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