Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-21-2002, 11:03 PM
EstebanSPI
Guest
 
Posts: n/a
300E Fuel Pumps and Filter Leaking

I just finished replacing the fuel injectors and fuel filter on my 89 300E.

As expected, it took more than the usual cranking time to start it after servicing, but it appears to be idling properly.

I left the fuel pump and filter cover off so I could check for leaks, and there appear to be several. The leaking is mostly from the banjo fittings on the end of engine-facing end of the fuel pumps and the new fuel filter. The fitting on the rear-facing side of the filter also has a slight leak.

The lower fuel pump and the plastic housing below it had a bit of residue from fuel and grime prior to changing the filter, so I think there may have been a small fuel leak previously.

Is it that the fittings on either end of the fuel filter just need to be tightened? How tight do they need to be? I was concerned about distorting the fittings if I overtorqued them.

I have a copper seal ring inset on either side of the fuel filter, and I am assuming that is correct.

In reference to the fuel fittings on the end of the fuel pumps, do they just need to be tightened, or are there seal rings, seals, or washers that need replacement?

Apologies for the length of this post. Any and all advice would be welcome. I really need to get this car back on the road (And not as a potential fuel bomb)
Reply With Quote
  #2  
Old 06-22-2002, 12:09 PM
Mike Murrell's Avatar
Registered User
 
Join Date: Feb 2000
Posts: 2,351
Hopefully you used new copper washers on the end of the filter. I had one begin to leak after replacing it and found that it needed more snugging up. I thought I had it tight enough , but didn't.
__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"
Reply With Quote
  #3  
Old 06-22-2002, 01:07 PM
csnow's Avatar
Registered User
 
Join Date: May 2002
Location: Mass
Posts: 1,127
There should be a copper washer on each side of those 'banjo bolt' fittings, one on the head side, and one on the other side.

Tightening really should work. The copper washers do all of the sealing here, though they must be flat and clean. This is not a place where you can add sealants, or teflon tape, or the like...

See image at:
http://www.eccentrix.com/computer/csnow/images/MBFP.jpg
__________________
1986 300E 5-Speed 240k mi.

Last edited by csnow; 06-22-2002 at 06:56 PM.
Reply With Quote
  #4  
Old 06-22-2002, 03:38 PM
EstebanSPI
Guest
 
Posts: n/a
An update from this morning..

On closer inspection, the copper seal rings on both fuel pump banjo fittings look old and tired. I am going to remove the entire filter and pump assemblies next week, and replace and retighten all fittings on the workbench. I have had enough of laying under the car with fuel dripping on me.
Reply With Quote
  #5  
Old 06-22-2002, 03:43 PM
EstebanSPI
Guest
 
Posts: n/a
Speaking of fuel pump and filter removal - Does anyone have a recommendation for disconnenecting the fuel supply hose from the tank before I pull out the fuel pumps?

Unfortunately, I have about 3/4 tank of gas. Do I need to drain the tank before this project?

Thanks guys for the replies so far.
Reply With Quote
  #6  
Old 06-22-2002, 03:47 PM
Registered User
 
Join Date: Feb 2001
Location: jErZeY
Posts: 514
This thing happen to me when i tried changing my fuel filter,I need to crowled under the car the gas smell terrible i didn't fix the leak so i had to bring to mechanic to lift the car for better access.It cost me $30.
Reply With Quote
  #7  
Old 06-22-2002, 04:19 PM
Mike Murrell's Avatar
Registered User
 
Join Date: Feb 2000
Posts: 2,351
You don't need to drain the tank, but you will need to clamp or plug the fuel line(s).

The previous poster mentioned an access problem. Fuel pump work on cars that have a rear-mounted pump is more easily achived if you first back the car up on ramps. You don't have to back up all the way, but enough to give you added crawling space. Afterwards, set the parking brake and block the front wheels. I always pull the ground strap off the battery too. If you create a spark by unintentionnally grounding something, you and the car may be unintentionally gone.
__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"
Reply With Quote
  #8  
Old 06-22-2002, 05:41 PM
pmizell's Avatar
Benz Zealot
 
Join Date: Jun 2001
Location: Houston, Texas
Posts: 838
I recently changed my fuel filter..

and was surprised to find that the new filter came with only one copper washer. You can buy these at Fastlane under the category 'tools and hardware'. Washer is what you're looking for for future reference.

Good luck

~Paul

__________________
'91 300E, 213K miles
Reply With Quote
  #9  
Old 06-22-2002, 07:12 PM
csnow's Avatar
Registered User
 
Join Date: May 2002
Location: Mass
Posts: 1,127
It's much easier if you can drain the tank.
15 gallons is a lot to contend with.
I was fortunate enough to have an oil extractor that worked fast on the 5 gallons I had in there.
If you got a cheap $10 siphon pump and 3-4 5-gallon gas cans, that would work too.

It may be possible to pinch off the rubber portion of the supply line. They make special hose-pinching tools just for this purpose, though you can use a big pair of visegrips and 2 pencils, chopsticks, or equivalent. The idea is to clamp it off without damaging the hose. Place one chopstick on either side of the hose, and squeeze them together with the visegrips.
__________________
1986 300E 5-Speed 240k mi.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 09:51 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page