300SE Fuel Pump

[OM618]

Is there a good fuel pump replacement guide around? I haven't been able to find one...

[tinypanzer]

W126 or W140?

[Ivanerrol]

This is a straight forward job. What's the problem? Joints corroded up?

[OM618]

It's W126...

Yeah I guess it is pretty straightforward...

But, I still can't find something: one of the guys at the auto-parts store said it also needed a strainer that they didn't sell or have in their system. He showed me an example of a strainer from a GM vehicle, it was a white cylindrical thing with a fine white mesh in it.

Thing is, I don't see anything on my 300SE except the pump and filter...

Does the 300SE require a strainer?

Also, I'm wary of expensive aftermarket parts, because it seems to me that expensive parts would warrant just going with OEM or premium brands. What is you all's take on it? Would an Airtex pump be sufficient over a Bosch?

Thanks.

[tinypanzer]

The strainer goes inside the tank and is a separate job from the pump.

Here's the gig:

Tools you need -

2 hose pinchers, or C-Clamps you can use to pinch off the rubber fuel hoses.
A set of open end wrenches, various sizes
Nut drivers for the fuel pump terminals
Fire extinguisher at arm's reach

Parts you need -

A Pump, and a complete set of copper crush washers for the job. You need 4 if I recall correctly. Might want to get those from the dealer, I have had bad luck with aftermarket ones being the wrong size. It's wise to do the filter at the same time

Job -

1) Disconnect the battery
2) Open the gas cap to release tank pressure.
3) Open the air filter and push the meter plate down. This will flood the motor, but will also release the stored fuel system pressure. Besides, that extra gas in the manifold will be useful when you try to dry start with a new pump.
4) Remove the plastic pump shroud, and the 2 power lines to the pump. You can get those rubber booties from the dealer if they are shot.
5) Use the hose pinchers to pinch off the rubber hose feeding the pump, and the one on the fuel accumulator. This will keep leakage and spray to a minimum.
6) Now you just have to remove the banjo fittings from the pump and filter. Beware of the spray, and use goggles. Hold the thing well, don't bend up the banjo fitting, and don't nick or gall the mating surface.
7) Loosen or open completely the clamp holding the pump and filter
8) Take out the old filter and pump, put in the new ones, installing new copper crush washers in the appropriate spots.

The rest is just reverse of removal. I don't think I've forgotten anything.......

[Ivanerrol]

While you are there, change the fuel filter.

There is another fuel filter in the lead in into the the fuel distributor.

[pawoSD]

Originally Posted by Ivanerrol

While you are there, change the fuel filter.

There is another fuel filter in the lead in into the the fuel distributor.

What? There's only one fuel filter on a gasser, aside from the tank strainer, but that is not really a filter.

[OM618]

Just a quick question:

I can get a Bosch fuel pump for $215 or a (re-branded house brand) Airtex for $152...

Is it worth it to just go with the Bosch?

[Ivanerrol]

Originally Posted by pawoSD

What? There's only one fuel filter on a gasser, aside from the tank strainer, but that is not really a filter.

Check this



And it's location

[OM618]

Well, I've attempted to replace my pump and filter, and here's what's happened:

My bolts are fused. The pump bolt in the fuel line and the filter bolt in the feeder hose are completely fused. I've been soaking them in WD-40 to try to loosen them up, with no luck.

I was just going to leave them in there and screw the pump and filter to the old bolts. However, some brilliant engineer decided it would be a good idea to change the fitting specs, so my brand new Bosch pump isn't compatible with the bolt from the original Bosch OEM part. Absolutely brilliant.

I'm at a loss to how to resolve this insanity. Should I start thinking about removing the fuel line to get better leverage on the bolt? What about the filter bolt on the feeder hose? Are there any products that any of you have had great success with loosening bolts with?

Much appreciated.