My mechanic wants me to replace the fuel pump on my '73 450SL (~80k mi.) due to a sticky check valve for ~$800. Is this something an experienced amature can change out (does not look too difficult)? Also, I notice the part price varies from ~$100 to $700, why?

 

Hi!
The fuel pump stays at the rear (in front of the huge fueltank. You will need a jack and put both rear wheels up in the air. You will need to drain all the fuel before doodeling with this. Then the exchange should be easy unless very rusty...
Well, my experience is that US part is the cheapest . for all kind of parts! (and/or on ebay,,,)
But you will defently need to rise up the car, and climb under it!

The check valves to the fuel, stays near to the fuelpump, but as a separated part!
What is the problem with your car, exactly!


Arildo, Norway
(and I also got a 1973 450SL, and need to do the same work) - Get a Haynes Book, -like me!)

 

Arildo, I recently purchased this (beauty, always wanted one) and took it into my trusted European Auto mechanic (works on all my Audis) to "baseline" it (full inspection, fluid(s) & filter(s) change, and immediate mechanical repairs) to make it roadworthy. In the process he stated that the fuel check valve was bleeding off line pressure making it hard to start (never really noticed it nor bothered me) and it best to just replace the fuel filter ($800 P&L), even though the fuel pressure is OK. The car is still intermittently sputtering, but my feelings are that this is spark plug wire related (he said they were OK). Beyond that I love the car and will slowly repair the other wear and tear an original 40 yrear old car would have. Thank you for the recommendation on the Haynes Book. The '73 allows me to do alot of work myself (have rebuilt cars in the past, but the '90's Audi's got way too complicated).

 

Hi again! I haven't been loggend on since spring, but that is because m whole garage burned down in autumn 2010.. Now its being rebuilt, and I can start work on my "new"450, 1973 model! (jepp, I still want the electronic injection system, and high power!)
I saw on a video clip, that this engine really need "Bosch W8DC" spark plug (and not the wr8dc, ngk or any crap the sellers will sell you) - The difference between "R" plug is that they got a built in resistor which make the engine to run "rough" on idle, and even worsh at high speed (but you cannot hear it then). I've just bought 16pcs W8DC plugs on ebay, and adwise you to do the same! (don't let the salesman say: "this is the same" for a different brand)!!

Arild