Help: I need a fuel pump for 300SEL 109.056 3.5 Bosch 0580 970 002

[sjefke]

OK, I am reviving this thread. I have the exact same early pump on my 111 280SE 3.5 coupe (with the 3 hose connectors) and it is leaking from the terminals. Pump works like a champ, except the leak which is starting to drive me crazy. And given that this is a $500+ pump new, I'd like to see whether I can repair it.

Cross-sectional drawing of workshop manual (see Service Manual Passenger Cars starting 1968 - series 108-113, section 07-20/4) seems to indicate a seal in the terminal block.

First question: has anybody ever take the terminal block out and repaired the seal?

Second question: I am looking to put a replacement in for the time being. Graham indicated that replacement pump is Bosch 0 580 454 999. I found a German forum where somebody was replacing the same 3.5 pump and ordered the 0 580 454 999 pump. He stated and verified that the pump he received was actually 0 580 464 042 (see w111 280SE 3.5: Umbau Benzinpumpe früh -> spät - Technische Fragen - vdh Forum). And on Ebay a replacement pump for Bosch 0 580 454 999 is listed at $47! (BMW FUEL PUMP 75-93 UNIVERSAL BOSCH FITS MANY MODELS | eBay).

I am tempted to get this one just to try it. I know there is a relief valve issue, but $47 versus $200+ seems to be worthwhile to experiment with.

I know I need to replumb some hoses, but am I missing something here?

Thanks,

Bert

[werminghausen]

hi Bert
I had exactly the same problem: terminals leaking and not much hope to reseal.

No need to spend a lot of money.
I did exactly this in the end: I bought a cheap pump and redid some plumbing (Take this pot out and connect the return line directly). There were concerns about the higher fuel pressure of the new pump witout pressure relief...but there is actually no problem except the fuel lines...so I redid all fuel hoses using the high pressure grade fuel hose for all lines downstream up to the pressure regulator.
Martin

[sjefke]

Martin,

Do you remember which pump (brand, model) you bought?

Thanks,

Bert

[werminghausen]

Bert
I think you can buy the Bosch CIS ones for $60 to $100 on ebay.
69609

for instance: Bosch OEM
Fuel Pump, Electric
For California models with chassis serial number from 043677. For Federal (non-California) models with chassis serial number from 043640. For models with CIS fuel injection (0580254942 or 61942 pump). 1 per car.

Martin

Originally Posted by sjefke

Martin,

Do you remember which pump (brand, model) you bought?

Thanks,

Bert

[t walgamuth]

I am parting my perfectly running 84 280e at the moment. If the pump on it will work for you I am asking $100.

[sjefke]

I scored a Bosch 0 580 464 005 pump from a 350sl that was on a scrapyard. For $20 I decided to get it, whether it was working or not. I just took it apart because it was not working (to be expected...). Two of the rollers had completely gummed up with rubber residue or so. Without the rollers, motor spins again. I have a suspicion that this one may also leak on the terminals, but this may give me a practice motor to see whether I can overhaul my old one. Like in Martin's pictures, this also has the housing crimped on. Internals look the same as the 0 580 464 002, except that there is a asymetric rubber seal, rather than o-ring in the roller chamber.

Right now, I have all rollers and cage soaking in carburettor cleaner.

I have a suspicion that these pumps are bulletproof from a motor and mechanics point of view and that the seals are the weak link. If we can figure out how to put new seals in these, it might gives us a way to keep these going in perpetuity.

Bert

[sjefke]

Just put the 350sl pump back together and it runs (dry) without a problem. We'll see how it performs under the car... I suspect it will leak because one of the seals had a tear.

Bert

[werminghausen]

Hi Bert, let us know when you find a cure for leaking terminals. I have my old pump packed up and ready to resurrect if there is way. The motor itself and the mechanics don't want to die...that is for sure.

[sjefke]

No cure for the leaking terminals yet, but attached are pictures of the 350SL fuel pump in pieces. You can see the roller assembly. Disassembling further would mean prying open the main housing and I want to test this thing first (Plan A) under my car.

This pump does not have nice round o-rings but shaped seals. I measured the one that had a tear and it it as about 112 mm long. One was broken and the other looked pretty flat, so I am trying a bandaid with massive liquid copper sealant. One thing I noticed is that the pump was a bit finnicky in running after reassembly. I did not run at first anymore and I suspect a roller got a little out of place. I only had to loosen the screws a bit and it started spinning again. I tightened it while testing the operation and all is well right now. We'll see how it is this weekend...

Plan B is also in the pictures: a new CIS type fuel pump. It seems to have the right diameter and all (and was only $45). One problem: it requires the banjo fitting and the D-Jet pumps have a barb fitting. I'll call the vendor tomorrow and see whether they have an answer. They listed it as fitting 71-73 SL, so I went on that. My gut told me that the BMW style pump looked like it had a barb on it. I'll verify tomorrow and see what I can work out.

Once I have one of these in my car, I am planning to disassemble my old one and see how I can get the terminals sealed again.

To be continued...

Bert

[werminghausen]

Bert,
correct you'd need a banjo fitting. I used a banjo I found from a diesel fuel line in my scrap box and attached the fuel line.
For the hose form pump to tank I used a super thick rubber hose in order to keep the pump stable and there a two different diameters at tank and pump. There is not much space down there to install the CIS (it is bigger than the old pump) but it is possible.
Martin

[sjefke]

I spent Sunday afternoon fiddling with fuel pumps. My son and I went to the scrap yard and I found a Bosch fuel pump with banjo fitting on a 70s BMW 525i. I took the whole thing. Pump looked good (Bosch 0580 464 071 - Made in Germany), but did not work. Banjo is perfect.

I talked to the guys who sold me the fuel pump and they were very accomodating. I got the BMW pump ($47) and it has a barb connection. I lined all up and you can see how they look. From left to right: 350SL pump, BMW Bosch 0580 464 070 replacement, Bosch 0580 464 071 (from scrap yard), Bosch 0580 254 910 CIS pump replacement.

Bottomline is that Plan A worked. The Bosch 0580 464 005 that I repaired from the scrap yard is now under the car and working perfectly without leaking. I left the accumulator connections, but plumbed the return line straight to the tank and elminated the connection to the (old) fuel pump.

I also researched the various Bosch pumps and found the following pressure and flow rates for the Mercedes pumps:
- Bosch 0580 970 002 (originally under Martin's 300SEL 3.5 and my 3.5 coupe): 2 bar, 100 liters/hour
- Bosch 0580 464 005 (350SL D-jet cars, like Graham's): 2 bar, 90 liters/hour
- Bosch 0580 254 910 (CIS pumps for which I got $44 replacement): 6.5 bar, 300 liters/hour
- Bosch 0580 464 042 (some Germans got these for 0580 464 999): 83 liters/hour, 4 bar

Then I looked up BMW pumps:
- Bosch 0580 464 048: 200 liters/hour, 3 bar
- Bosch 0580 464 070 (I got the replacement for this for $47): 130 liter/hour, 3 bar

It looks like the BMW pump with the barb that replaces Bosch 0580 464 070 seems to be the best fit by flow rate and pressure for the old D-jet Mercedes pumps. Going from 2 bar to 3 bar is nothing compared to going to a 6.5 bar CIS pump. The catch of course is that the BMW pumps are smaller in diameter. I did not put the BMW pump under because I would have to create a sleeve for it. Nevertheless, I am going to return the CIS pump and keep the BMW pump as reserve. And it is a tight fit for any of those pumps in these old cars if you want to keep the fuel pump cover shield. I attached a picture with the 350SL pump under the car.

Next task: getting my Bosch 0580 970 002 apart.

Martin, how did you get the rear cover off from the pump? I pried the tabs back, but is there a trick?

Thanks,

Bert

[sjefke]

I finally have my original pump disassembled. The housing was a pain because the tabs were slammed down with "Deutsche Grundlichkeit" and it took some bending and a bit of cutting to get them clear. Once I was able to put a knife in between the housings, it started to move and revealed the big o-ring Martin mentioned. Housing pulls off easily (you have to overcome the magnetic force) and you end up with the motor assembly as in the first picture below. There is plenty of metal overlap between housing and o-ring so I should be able to bend everything back with no (leak) problem if I reassemble the thing.

Next you need to pry the 3 springclips off the board (I don't think Martin attempted this). Small watchmaker type screwdriver will take care of that quite nicely. Once they are off, you can lift the board up and you see the wiring under it (see fp_008).

Wiring is very simple. The aluminum colored wire to the left is the ground and is crimped under a ring. The copper wire is plus and is soldered to brush terminal. In the middle you can see the terminal plug where the wires stick out. I saw that there is no nut holding the terminal so I figured it was a press fit and started to pry the terminals up. And indeed they started to come out (see fp_009).

Of course I pulled a bit too hard and the terminal came out and snapped the ground wire and stretched the resistor wire a bit. Hindsight I should have cut the ground wire at the pressed ring, and the main wire at the brush solder point before pulling hard on the terminal. Now I have to rewind the wiring a bit to restore the resistor.

The terminal has indeed an o-ring which can be replaced (see fp_014). I have not measured it yet, but will do in the near future. Once replaced, the terminal block should puch straight back in. It has a bit of a conical (plastic) spring action. Note that you need to cut the wires in order to get the new o-ring on. So that means resoldering or crimping the brush wire and reattaching/soldering the ground wire, which can be interesting challenges given the size of the wiring.

So, these things should be repairable for a lot less than the $500+ that MB charges for a new one, if you are inclined to go this route.

To be continued...

Bert

[tram]

In a pinch, an Airtex E2000 pump (for a Ford Ranger) is a damn near perfect replacement for D-Jet cars. There's a little extra plumbing involved, and sometimes you might have to cycle the key a few times to build up pressure as there's no check valve, but it's cheap, it's available everywhere, and it works.

[werminghausen]

Originally Posted by sjefke

I finally have my original pump disassembled. The housing was a pain because the tabs were slammed down with "Deutsche Grundlichkeit" and it took some bending and a bit of cutting to get them clear. Once I was able to put a knife in between the housings, it started to move and revealed the big o-ring Martin mentioned. Housing pulls off easily (you have to overcome the magnetic force) and you end up with the motor assembly as in the first picture below. There is plenty of metal overlap between housing and o-ring so I should be able to bend everything back with no (leak) problem if I reassemble the thing.

Next you need to pry the 3 springclips off the board (I don't think Martin attempted this). Small watchmaker type screwdriver will take care of that quite nicely. Once they are off, you can lift the board up and you see the wiring under it (see fp_008).

Wiring is very simple. The aluminum colored wire to the left is the ground and is crimped under a ring. The copper wire is plus and is soldered to brush terminal. In the middle you can see the terminal plug where the wires stick out. I saw that there is no nut holding the terminal so I figured it was a press fit and started to pry the terminals up. And indeed they started to come out (see fp_009).

Of course I pulled a bit too hard and the terminal came out and snapped the ground wire and stretched the resistor wire a bit. Hindsight I should have cut the ground wire at the pressed ring, and the main wire at the brush solder point before pulling hard on the terminal. Now I have to rewind the wiring a bit to restore the resistor.

The terminal has indeed an o-ring which can be replaced (see fp_014). I have not measured it yet, but will do in the near future. Once replaced, the terminal block should puch straight back in. It has a bit of a conical (plastic) spring action. Note that you need to cut the wires in order to get the new o-ring on. So that means resoldering or crimping the brush wire and reattaching/soldering the ground wire, which can be interesting challenges given the size of the wiring.

So, these things should be repairable for a lot less than the $500+ that MB charges for a new one, if you are inclined to go this route.

To be continued...

Bert

Hi Bert, this is great news! You are a pinoneer
Replacing the o-ring in the terminal should be easy. Can you measure the size?
I believe this o-ring was the cause of my pump leaking but stopped concentrating on this one because my cheap CIS pump is doing a good job. But I will try and bring life back to the old pump.
Martin

[sjefke]

Finally did some o-ring groove measurements with calipers. I measured inner and outer diameters (ID & OD) of the housings or grooves the o-rings fit into. So these are the groove dimensions:

Terminal: ID = 8.8 mm, OD = 11.5 mm
Main housing: ID = 51 mm, OD = 55 mm
Outlet housing/flange: ID = 30 mm, OD = 36.5 mm

Outlet housing groove o-ring had plenty of space. Its thickness was on the range fo 1.5-2 mm. Roller flange o-ring seems to be the same size as outlet housing o-ring.

These are the various groove measurements. I have not looked into which modern o-rings would fit.

Bert