Hello All:
It's been about 2 years and 10K miles since the fuel filters have been changed on my sons '84 300D. This will be the first time I've done it myself. I figured I do it this weekend before the weather turns too cold. Any things to look out for when doing this? Any trickes? I'm planning on changing both the in-line & spin on filter. After the new filters are in place - do I just use the manual thumb pump to remove any air in the system?
Thanks in advance,
Kbike

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01 VW Passat 4motion
99 VW Eurovan
84 MB 300D
93 BMW K1100RS

The in-line filter is a no brainer. The spin on filter, loosen the big nut on the top of the housing, then spin the filter off. Install both filters leaving the big nut a little loose. Then turn the hand pump counter clockwise and pump till the air bubbles go away. Should take 5 -6 pumps. Then tighten the big nut. Also tighten the hand pump clockwise. Start car and check for leaks. It's easy.

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1984 300D Turbo Sedan (Hilda) 272,115 miles.....
Anthracite Gray/Palamino Leather, I am 3rd owner

2001 Dodge Stratus (Silver) (wifes) 55814 miles...

1982 280TE Wagon Astral Silver Metallic/
Anthracite Velour
260,512 miles (Eva)

1969 230 Sedan Olive Green/Black MBTex
4 Speed Manual
84,213 miles ????
Haus Frau


2004 Boreem Ninja Pocket Bike
Highly Modified 49cc (Ling Ling)

Einigkeit und Recht und Freiheit

Takes about 15 minutes.

The bolton the filter is 24mm, and make sure you fill up the new filter with fuel from the old one...makes for less pumping on the manual pump. I usually have my wife crank on the engine will I pump the manual pump to primer the engine, seems to work faster that way.

Good Luck.

As has been said, this is really easy. The only thing I'd add is to be ready to plug the fuel line when you remove the inline filter, otherwise fuel will leak everywhere.

I would recommend removing the main fuel line where it enters the inline filter FIRST, plug the line, THEN remove the filter from the pump. If you do it in this order you won't be stood holding the inline filter with fuel gushing from the end.

I did both mine in the dark for the first time a few days ago, and it was a 10 minute job.

Kevin

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'85 300SD

When you do the in-line filter, purchase 2, one for a spare to keep in the glove box or trunk. A one time incident with dirty fuel can leave you stranded without a spare.

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Sam

84 300SD 350K+ miles ( Blue Belle )

My hand pump leaks so bad it doesn't work so I filled the new spin on with diesel , cranked it up and as soon as it fired started pumping the throttle. It was wanting to die on me but I just kept pumping the throttle and it cleared up in a minute or so.

Benzzy-I'm gonna try your method next time.

Cheers,

Bill

Bill:

Replace the hand pump with the "thumb" pump (no more unscrewing) -- it will leak air in if it leaks fuel out while pumping, and sooner or later the IP will run dry.

Take fuel filler cap off before opening the lines -- not too much of a problem this time of year, but if it's warm the tank will be slightly pressurized and fuel will pour out all over the place. Smelly at best...

Do the change with the engine warm, too. That way it will start right up and pump fuel for you, helping to purge the air out of the fuel filter. If you don't get all the air out on a cold engine, the battery may go flat before it starts!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter I don't think the IP can run dry due to leaking primer pump because when you screw the pump "handle" back down doesn't that close it off like turning off a faucet? My Iveco box truck had a Bosch IP. It leaked too when using it to prime and once I left it open. Took off spraying fuel all over the place. It never ran out of fuel.

What is a thumb pump and where can I get one?

Thanks...

Cheers,

Bill

You can get the thumb pump at fastlane, its a great price, and it will never leak.. (Fastlane is at the top of this page, there is a banner that says "New and much improved FASTLANE" ) It is under "diesel injection" Then "primer pump" (after you enter your car.)You will not need the whole Primer poum assembly, just the pump itself. (I just did this on my 300SD) You will probably need a crows foot wrench, and I fairly sure it is a 17mm.

Thanks Sady. before I do my next filter change I will surely get one.

Cheers,

Bill

Peter,
If the tank is pressurised then you have a problem with the tank vent. Clean it and you will not have a pressurised tank.
Another issue is when you have a full fuel tank, the fuel level in the tank is higher than the fuel line outlet and fuel will flow out under gravity pressure. If this is the case, you can park facing up a hill to change the prefilter.

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Tony from West Oz.
Fatmobile 3 84 300D 295kkm Silver grey/Blue int. 2 tank WVO - Recipient of TurboDesel engine.
Josephine '82 300D 390kkm White/Palamino int.
Elizabeth '81 280E, sporting a '79 300D engine.
Lucille '87 W124 300D non-turbo 6 cylinder OM603, Pearl Grey with light grey interior


Various parts cars including 280E, 230C & 300D in various states of disassembly.

It's normal for the tank to hold minor pressure (hence the instructions in the owner's manual to vent it before removing the filler cap), so do yourself a favor and take the cap off. Keeps the mess down.

As to the hand pump, the seal on the piston is also the closing seal -- if it leaks fuel out while pumping, it will definitely leak air IN while running. If you get any restriction in the line or tank screen, you will "run out of fuel" when it sucks in enough air, and it will be a HUGE PITA to get started again. BTDT.

The replacement is a sealed version that you just push down on, no unscrewing, etc. Take a look on Fastlane on this site.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

What is the hand pump? Is that something I have to buy? Can someone post a pic?

Thanks.

If you have a w123, it is on the injection pump. 2" knob, towards front of the pump. Unscrew it--counter clockwise---and pump up/down. Don't forget to tighten it back down. Then tighten the bolt on top of the filter.

BUT, if yours is anything like mine, it probably doesn't work. You'll know it doesn't if fuel starts squirting out around the stem of the pump. You can buy a replacement pump [aftermarket] or just fill your filter with fuel, install the filter, and crank it, being prepared for stall. I keep mine revving to keep it from stalling because if it does [stall] you'll wear your starter out cranking it. Takes a lot of cranking to pressurize the system again.

Hope this helps...

Cheers,

Bill