Here's my payback! Diesel Primer Pump Replacement - Page 2 - PeachParts Mercedes-Benz Forum

nhdoc · #16 02-27-2006, 01:10 PM

If you don't care about saving the old pump you can simply grab the body of it at the top with vice-grips to break it loose, then unscrew it and replace it with the new pump which has a body slim enough to fit a crow's foot wrench past to tighten. The whole job can be done in under 2 minutes if you do it this way...

stevo_61 · #17 02-27-2006, 01:18 PM

That job has worked its way to the top of my list. I will reference your pictures for sure. This is why Al Gore invented the internet.

1983/300CD · #18 02-27-2006, 01:32 PM

After looking at the pictures, I swear I can almost smell diesel.

dougand3 · #19 11-10-2006, 10:18 AM

Super "How To", pwogaman. Another question...

I see the Monarch brand - Cream colored gear on top and the Bosch brand - black cylinder. Is the Bosch preferred over the original part? Thanks, Doug

mobetta · #20 11-10-2006, 10:27 AM

the replacement is a nice plunger assy that doesn't seem to devolope leaks as much. also, you just pump it, no screwing around. however, if you are greasing, the old style will pull veggie better.

macdoe · #21 10-05-2007, 07:32 PM

Hello, This is my first post to your forum.
I have been reading the DIY links for about a week now.
I purchased my first Mercedes Diesel car about two weeks ago. It did not run when purchased. The guy I bought it from said it had a dragging starter however upon investigating a clicking noise when turning the key,found out the battery clamps needed to be tightened and a re- charge via trickle for a day or so. turned the key and found the starter to be fine, but would not fire.
Found out the car had been sitting for a while, spoke to a friend at work who showed me where the primer pump should be using one of our international diesel delivery trucks as an example. I gave that a try and cracked open the injector line at the injector to release air in the system as my friend advised. This did not work to release the air as after trying this the car still did not start. I got my brother to turn the starter over as I cracked the lines at the injector. He killed the battery probably because the glow plugs kept coming on every time he stopped cranking. At one point I noticed the glow plug relay was glowing orange. I put the charger back on the battery for the night and picked up a new primary and secondary fuel filter after work the next day. Changed them and primed the pump again. Got my brother back over to turn the motor over while I crack the injector lines. Started at the front of the motor and worked my way back to I think the third injector and whoola It started. I was very happy, and very dirty but it was worth the extreme happiness that this non running car I had purchased was not someone elses junk.
I let the car sit and idle for a while in front of my parents house and cleaned up my tools before heading out on the highway for the drive home.
I went back to check the guages about 5 minutes later and was surprised to see my car sitting in a puddle of diesel. I carefully turned it off to check where the leak was coming from? Turned out to be a small line that runs from the trunk to a hard line right above the rear differential. The small hose clamp broke off at some point in time and the fuel must have been coming from there. I put a new one on for now as this hose and the ones next to it do not look good.
After reading the forums I think I should replace these hoses but it looks like it would be alot easier to remove the fuel tank.
Is the manual lift pump something that will come apart for replacement of o-rings or something? This pump works but leaks fuel everywhere, The MB dealer does not stock this part in my region. I am cheap and have o-rings on hand besides it still works but I would like to fix the leak.

KAdams4458 · #22 10-05-2007, 07:41 PM

Quote:

Originally Posted by joro

Do yoiu guys think this may solve a problem with air in the system i have?
my 300d running on veggi has been leaving me stranded 5 or so miles into a trip,i have to get out and hand prime to take off again,but when i hand prime(older style primer) its loose and almost no suction,if this is the case can air be getting in thru there???
huge thanx

It seems to have solved mine. With the old pump, I primed and primed. I had a puddle of fuel under the car to show for it, and tons of tiny air bubbles showing in the clear fuel lines. I installed the new pump, pumped it a few times, and voila! No bubbles! No puddle! It can definitely be a source of air leakage in to the lines.

nickofoxford · #23 03-25-2009, 06:57 PM

Quote:

Originally Posted by KAdams4458

It seems to have solved mine. With the old pump, I primed and primed. I had a puddle of fuel under the car to show for it, and tons of tiny air bubbles showing in the clear fuel lines. I installed the new pump, pumped it a few times, and voila! No bubbles! No puddle! It can definitely be a source of air leakage in to the lines.

Especially because the WVO goes no-mercy on rubber seals.

BTW very nice write up! I will be using this.

toomany MBZ · #24 03-25-2009, 10:55 PM

Quote:

Originally Posted by macdoe

After reading the forums I think I should replace these hoses but it looks like it would be alot easier to remove the fuel tank.
Is the manual lift pump something that will come apart for replacement of o-rings or something? This pump works but leaks fuel everywhere, The MB dealer does not stock this part in my region. I am cheap and have o-rings on hand besides it still works but I would like to fix the leak.

I had a mechanic install the two rubber lines at the bottom of the tank. Unless you want to clean it out, leave the tank alone.

Can you determine just where the lift pump is leaking? Are you referring to the primer pump? If so, replace it. No "O" rings.

mbrl93 · #25 03-26-2009, 09:42 PM

Quote:

Originally Posted by mplafleur

I replaced mine a couple of months ago as well. I think it was a $17 part. I did not have to disconnect the fuel line though.

I have a 93' E300D-turbo with a self-primer,hard cranking. Where did you install the pump and how? Did not have much success running wvo, presently running bio. Thanks

mbrl93 · #26 04-02-2009, 08:39 PM

What are the pressure ratings, also the model #. Checked at NAPA, so many choices, starting at $65. Can you be specific about the install area and procedure.
RLL

Hosenpants · #27 04-04-2009, 05:57 PM

Thank you to the OP for taking the time to post the replacement procedure. Lord only knows why I didn't find this thread 2 years ago when my replacement pump showed up (and I became stuck as to how the heck are people getting a wrench around the installed one!?!?) The replacement pump soon went into long term storage as our kiddo arrived 21 months ago. Just like the cats, messing around with Putty took a back seat to our new life.

Until today! Just this morning I swapped out both fuel filters and replaced the damn pump. Simple work sure, but VERY satisfying.

Never would have had the guts to remove the fuel line fitting without reading about it. Thanks again.

fruitcakesa · #28 04-04-2009, 10:32 PM

This has come at the perfect time as I am expecting the new pump on Monday. The oldy leaks so much when in use it gets all over the motor mount, makes a big mess and wastes my precious fuel!
Thanks for the writeup.