Fuelpump rebuild: Bosch 0 580 463 009, Fuel pump - 1974 1.8 Options

[wonkipop]

think this is the right section of the website to put this in.
even though its a spanner job, the material is historic and possibly of esoteric industrial archeology interest. who knows?
1.

background.
i recently recommissioned my 74 1.8 after nearly 16 years of storage.
i paid for storing but i always knew i would. complete rebuild of fuel system.
we got the original fuel pump to come to life but it bled from every orifice.
flow rate was ok however and motor still worked fine - just a minor fire hazard.

2.
action.

to get the car up and running we took out the original 0 580 463 009 fuel pump and re-plumbed for a modern two port in line pump. car runs.
having done that, in some ways i felt the plumbing was a little compromised over the original given the pump needed to be repositioned to have a line in the back as well as out the front making the line out a pretty tight turn to get up into the engine bay. but it runs.

3.

delayed dream due to thoughts of it being a nightmare.
in the back of my mind was the idea of rebuilding the original fuel pump.
general consensus down here at the bottom of the world (aus) was don't bother, its a sealed unit and unserviceable.

4.

then. a young guy with a 1970 citroen DS21 IE inspired me. he had taken his similar bosch 3 port pump apart and rebuilt it proving its possible if you are determined enough.
i think the pump in the citroen was a 0 580 463 005, which the 009 replaced
not sure when the 009 came in, but its before the 010 (which is the completely different pump and fitted to the later 75 and 76 cars - amongst the first of the in line 2 port types). maybe the historians know exactly when 009 kicked in, i'm guessing it comes in with the L jetronic in 74 model year, but it could be earlier. externally a 005 is indistinguishable from a 009. i might have discovered the difference internally in what i have taken apart to date.

TAKING the 0 580 463 009 apart.

STEP 1.
undo the 4 screws securing the pump and outlet housing on top of the unit.
keep it all upright and vertical.
remove the top part of the housing.
remove the upper o-ring.
remove the metal pump vane and the five cylindrical magnets housed in it.
(bag them so you don't lose them - they seem to be weakly magnetic cylinders).
remove the vane housing.
remove the lower o-ring.

If your pump is only leaking from this upper housing its an easy fix.
just replace the two o-rings and put it all back together.

Don't need to post pics of this stuff its very simple to do.

the o-rings are 30x2mm i believe. could be 31x2mm. yet to confirm.
still to make the trip to the specialist o-ring shop here in melb aus.
i'll be looking to find the best fuel resistant o-rings i can get hold of.

suprisingly these o-rings were still in good shape in my pump and were not the source of the leaks. but i will be replacing them.

[wonkipop]

i have worked out how the pressure relief valve and check valve work.
all in one in these pumps.
one little seat valve that is slotted does both functions..
the first section of the tubular valve is circular with a small rubber teat that sits into a valve seat.

then there is a groove and a second groove.

after the first groove the tube has a flat section that will allow fuel through.

the two springs are progressive and fit inside each other.
first small spring is for the normal operation of the pump and the check valve function.
approx 35 psi or whatever is required for particular pump variant fully opens the check valve function by pushing the valve open against the first spring and opens up the port to the outlet or discharge port. the outlet is through the valve seat.

if pressure builds past 35 ibs it floods the tube with the valve in it and pushes it further until it engages with the second larger spring. at 70lbs it pushes it far enough for fuel to flood past the front circular section and into the section with the flat part and then fuel escapes into the relief port.

saab pump was good in that respect. the 009 out of the 914 took a fair bit of cleaning and even some honing by hand with 2000 grit sand paper wrapped around a drill bit to make the valve slide easily again in its cylindrical chamber. there was stubborn residual gum that even ultrasonic cleaning could not seem to dislodge.

both pumps have been tested to pressure relief - 70lbs. both opened fully at that pressure and released through the relief port.

these pumps are precision mechanisms and have 0 tolerance anywhere.
i discovered reassembling 009 914 pump that the port body had lifted very slightly by less than 1mm against the outer motor casing on one side when i had reassembled and crimped.
this was enough to bind the pump axle very slightly with the roller cell vane and cause the pump to not reach spec pressure the first time it was run.
i realligned them and got it absolutely even all round - gave the crimps a bit more of a tap.
was enough to lift the pump performance from marginal to upper end of spec.

interesting stuff germans made. no slop anywhere.
there is a bit of long axis play in the electric motor axle up and down, thats all and its designed to have it.
the rest has to be exact.

i found a cross section cut pump on the mercedes benz heritage website.
shows pressure relief / check valve though does not necessarily make any clearer how it works.
fuel moves through the tiniest of holes.
the cross section pump has the valve located in the fully open fuel delivery position and on its way to the 70lb pressure relief position.
a mercedes tech manual for late 60s models also contains tech information and specs on the three port pumps. this cutaway pump and the tech merc tech were the only source i was able to find. everything else deals with later in-line variant of the pumps.

never had problems with vapor lock with this car before recent rebuilding of the fuel system and replacement of plastic tunnel/engine bay lines with mild steel. now i do.
not major but car will on occasion require more than normal cranking to restart hot.
i believe its not the pump doing this but the lines themselves.
original plastic lines did not absorb/conduct heat like the metal ones do?
i think fuel vaporizes in the section of line from the tunnel to the pump.
a minor issue and i can live with it as the car does not refuse to restart.
also figure if i change to front pump location this problem would still be there in that section of fuel line.

will put the original pump back in the car and bag the spare saab pump with desiccant after pickling it. should easy last me to the end.
best information i can find says to pickle them with shellite (or i think its called mineral spirits in the usa) - then cap them.

still can't find anyone to rebuild the merc pump commutator. its a lost industry.
even ten years ago there were shops around that rebuild starter motors, esp, for trucks.
they have all disappeared - retired. either australia really has become a nation of soft handed screen punchers or cheap chinese parts ruined viability.

electric cars are going to be interesting.
rebuilding / reconditioning electric motors might become a sought after skill again?