Author Topic: cold start valve leaking  (Read 7153 times)

gnj588d

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cold start valve leaking
« on: March 09, 2011, 21:37:21 »
when I start the engine I have a fuel leak at the base of the start valve it stops once the engine is running,looks like a leaking gasket or seal ring?problem if so can I buy the gasket or seal on its own.its not coming from the small screw.Many thanks Mike

ja17

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Re: cold start valve leaking
« Reply #1 on: March 10, 2011, 02:16:04 »
Hello Mike,

You should make sure the CSV is not leaking all the time. Turn the ignition on, (electric pump running) engine off, and remove the small 7mm bolt. If fuel leaks more than an occasional drop. The unit is faulty. Just because it is not leaking when the engine is running is not valid, since the suction from the engine will draw leaking fuel into the intake and cause a rich idle.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

gnj588d

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Re: cold start valve leaking
« Reply #2 on: March 10, 2011, 10:17:52 »
Hi Jo done as you suggested and there is no fuel leaking when I remove the 7mm screw,with the pump running its leaking from the joint between the magnet and the body its screwed to {between the two faces] any ideas?Cheers Mike.

jacovdw

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Re: cold start valve leaking
« Reply #3 on: March 10, 2011, 10:38:48 »
There is a small (and very expensive) o-ring that is responsible for a seal between the CSV body and the solenoid.

Part number A001 997 75 40 I believe.
Very easy fix if you can get over the pain of the price (13 Euro) for such a small o-ring...

dseretakis

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Re: cold start valve leaking
« Reply #4 on: March 10, 2011, 12:34:05 »
If I remember correctly there us a paper gasket where the CSV mounts to the manifold. This is also very expensive for what it is. Next time I will remove the old gasket and trace it on some paper gasket material to make my own.

Naj ✝︎

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Re: cold start valve leaking
« Reply #5 on: March 10, 2011, 13:07:30 »
If I remember correctly there us a paper gasket where the CSV mounts to the manifold. This is also very expensive for what it is. Next time I will remove the old gasket and trace it on some paper gasket material to make my own.

The gasket is used on later (70/71) 280s with a smaller CSV.

Early ones use a rubber 'O' ring.

Naj
68 280SL

dseretakis

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Re: cold start valve leaking
« Reply #6 on: March 10, 2011, 14:37:04 »
Thanks for the clarification. I was getting confused!

gnj588d

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Re: cold start valve leaking
« Reply #7 on: March 10, 2011, 16:02:51 »
I have taken the c.s.v. off and found the little rubber seal has disintergrated,what running problems would that have caused. thanks to you all for the input, you saved the day again.Take care Mike ;D

gnj588d

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Re: cold start valve leaking
« Reply #8 on: March 19, 2011, 12:31:05 »
Fitted the new o ring and no more leaks,job done, thanks again everyone, especially Naj