450 and 6.9 fuel pumps

[adamb]

I've been putting my 6.9 to a lot of use recently. The weather has been good so why not. Yesterday I noticed that the fuel pump is making a loud whine. Sounds like it's on its way out; need to replace before I get stranded.

I have an old pump removed from a 450 which is Bosch 0 580 464 014. I don't know if it would be the same as my 6.9 but I suspect that it's likely given that the 6.9 has virtually the same K-jet set-up as it's smaller sibling. This pump appears to be obsolete. A quick search reveals that there are replacements sold on eBay etc. Any recommendations for a replacement?

[TJ 450]

Yes there probably have been a few revisions. It is the same pump for both 6.9 and regular 450SEL though, also 1st gen W126, W201 etc.

Tim

[adamb]

Do you think that an aftermarket pump may supply a different volume which could result in different pressure?

[koan]

Don't think 450 and 6.9 are the same.

6.9 pump takes a larger diameter non return valve on the output - which are hard to find.

[motec6.9]

Hi guys I always though it was the same as a Bosch 040 model pump http://www.boschfuelpumps.com/

[adamb]

Hmm, sounds like I'll need to take out the existing pump to compare against the 450 item. In the worst case I'll be looking for a confirmed compatible item from the Bosch list. Does anyone have the 6.9 fuel pump part number at hand?

[KenM]

Acording to the epc there are 3 versions of fuel pump, Benz part No. 002 091 09 01 up to chassis 345, also used on 032 and 033, seems to be obsolete now, second one is Benz number 002 091 13 01, up to chassis 2468, Bosch number 69513 still available, third version Benz number 002 091 97 01, Bosch number 69609, available but may also have been superseded (check AutohausAz for details).
All these pumps used on 032 and 033 at various times also, depends on chassis number.
Cheers,

[WGB]

From memory I think there were updates on the accumulator and one way valving at different stages.

With a final revision in late 1978 or early 1979.

The differences should be shown in the workshop manual

I am sure the pump pressure would not have changed but it is possible that there were different fittings at either end.

It is possible that that these fittings are removable and interchangeable anyway.

Here is the pump, filter and accumulator in a December 1978 build 6.9 #5554



And the same view from the other side before hose replacement and with the rear axle and subframe assembly removed



Bill

[TJ 450]

This is the first I've heard about any physical differences. I have previously interchanged pumps, and the check valve assy was the same on all K-Jet pumps up to gen 1 W126, that I have seen. I guess it's possible that the early versions were different.

Tim

[koan]

Early versions of the pump had an internal check valve in the output connection, later version didn't have the internal valve and uses the external valve. Don't know of any others.

Early 6.9 pump setup had an accumulator with two ports and used lots of rubber pipe and fittings, later version had an accumulator with only one port and a three way metal "spider" to connect components together. Thers is a third setup which I've never seen which throws in some sort of compensating valve to help with cold starts.

The pump on my 6.9 died many years ago, don't recall which version its was, think it had the external check valve. Replacement from MB came with an external check valve in the box.

Recently I ordered a new check valve from a US supplier, was the wrong one - too small diameter, went to my local parts supplier, he tried to look up the check valve but it's not listed in the EPC. He had a few of check valves in stock, all were small ones.

I finally got one from MB Spares in Canberra, they seemed to know the differences.

I have both valves here, I can take pics to show the different diameters

[WGB]

The workshop manual under CIS fuel system shows the different types

http://handbook.w116.org/Engine/107/M117_45/073-283.pdf

This shows the differences between two types with scematics but I think there was a later one for US emission cars as well.

http://handbook.w116.org/Engine/107/M117_45/073-275.pdf

Bill

[koan]

Maybe there are only two arrangements of fuel pump connections, I thought there were three.

And about 450 and 6.9 pump check valves (and fuel pump outlet sizes) I may be confusing 280 vs. 450/6.9 pumps.

[WGB]

I think thge third version was US only froim memory Koan.

Bill

[oversize]

So to clarify are 6.9 and regular 450 pumps the same if they're from the same version?

[robertd]

From experience they are totally interchangable