Takid455

Want to replace the fuel pump on the 56. Current one is a dual pump and is leaking. Rather than rebuild it as I dont need the vacuum pump portion any more, I'd like to replace it with a simpler / newer design . Does such a part exist or interchange with the 303, 324, 371, 394 engine family? Newer SBO units work?

redoldsman

It may not be what you want to do but I have an electric pump on mine. It is mounted back near the tank. I used a block off plate for a big block chevy that fit the Olds block perfectly. There are some safety provisions you will need to make if you use an electric pump.

Tedd Thompson

I'm not sure why you don't still just rebuild or replace the original pump. The vacuum pump poses no problem if you don't use it, they last for years and years and you don't have to re invent the wheel. Cost would be about the same with no additional plumbing or wiring needed. Any later model Oldsmobile fuel pump 57- 60 would have the same dual action diaphragm if they would or could be adapted and the later second generation engines styles would be complexly different in design and not apical to this adaption. Electrical is a cheaper alternative but in my experience (some years ago) they have a short life and all the ones I've known sound like woody wood pecker is under the seat. They may have changed for the better in the last 10 years I don't know but original has always been good for me.....YMMD....Tedd

Takid455

Both are viable options. Did ponder the electric pump setup. I'd probably do an in tank setup if that was the choice.

Current pump was rebuilt a when I got the car several years ago and has seemed to have an issue. Leak started small and has progressively become a steady drip/ flow from the vent hole. Perhaps diaphragm ripped. Car still runs great. Pump is on the bench so I'll need to dig into it.

Doesn't look like there is a newer style replacement so its either rebuild or OE or electric.

54oldsmobile88RW

Tedd, still just plugging along with the engine. I'm going to go the smart route and eventually get an electric wiper and I've already wired for an electric washer pump. Question is, can the vacuum connections be plugged without any adverse effects?

Tedd Thompson

Not a issue. I still have the vacuum lines headed under the dash just for appearances, the judges like that but they are plugged off.... Tedd

54oldsmobile88RW

I can only guess where the lines went, most feel away from rot and the steel line was cut and pinched off. No matter tho, I'm just making a driver. Show quality requires $$$. I'm sticking with make it work and drive... rust dust we must

Ozzie

I'm assuming that your leak is a fuel leak, and not an oil leak, though the pump can leak oil also through the "vent hole". You probably will not be able to find a single diaphragm pump (fuel only) that will do what you want. In 1959 Olds started using some electric wipers. That year there were multiple fuel pumps. The ones without the vacuum diaphragm were part numbers 5594726 and 5594538. However, the pump's rocker arm also changed from the 1958 engines to the 1959 engines. Hence, a direct exchange is not possible. The single and dual diaphragm pumps for 1959 will interchange, but not with earlier years. I've never tried to transplant an earlier year pump rocker arm into a '59 single diaphragm pump, so I don't know if it would work. If you do that, please let the rest of us know how it "comes out". I don't know of any newer Olds engines that used a pump which would do what you want. (The aluminums and SBO & BBO 2nd generation won't work.) But, if you want, you could rebuild your pump and omit the vacuum portion. The fuel section should work properly even with complete absence of the vacuum portion.

54oldsmobile88RW

Tedd... if you're still out there.... I'm rebuilding my dually. I got the kit from Fusick and all seems to be correct. Except! There are apparently 6 small gaskets that are the same size as the check valves, 1 small red rubber seal, and a steel barrel sleeve. None of the above have i found on the original. Although, the original had red rtv around the diaphragm rather sloppily making me think i was rebuilt once perhaps bad in the 70s or 80s before she was stored away for all these years. Are there any links too reference or advice? My first time going this route as in the past i haven't had a dual operation type and new was the cheaper way. Thanks.

or anyone else that wants to chime in! LOL

Tedd Thompson

Probably that kit is a universal kit and will work on many years of fuel pumps and you end up with extra unused parts when that happens. I don't remember a steel sleeve or small gaskets but it's been quite a few years sense I did the last one.

There is a you tube on rebuilding this fuel pump that was helpful for me the first time I did one, I'll see if I can find it and I'll leave you a link.... Tedd

I did a quick search and found one for a 55 Buick, couldn't find the one on the Oldsmobile pump. It looks to be the same style as the Oldsmobile and should come apart and together about the same. This may help in you getting it back together ......

54oldsmobile88RW

thanks Tedd. I never would have thought of staking in the check valves. He did some part changes with 3 different pumps but very good info. Thanks again. Stop by and help pull the engine anytime. Lol

Ozzie

Look in the Oldsmobile Shop Manual. There should be a rebuilding procedure there with photos. Be sure to check the castings for distortion where it seals against the diaphragms. Lay it on a piece of glass. It must be "true" or you will get a leak. That's probably why the red RTV was there.

Tedd Thompson

Also just as a after thought when replacing the vacuum dome use a couple of 8/32 x1 1/4 machine screws Which are longer than what you just took off to help take the tension off the diaphragm spring. Once the dome is secured replace with the original screws. It makes aliening the dome a lot easier. A vice is a handy gadget also unless you have more than three hands.... Tedd

54oldsmobile88RW

thanks. I've been reading the shop manual. It's great to have but i like pestering you guys as well lol. What you said makes total sense. Thanks

54oldsmobile88RW

saw the long screw steps in the manual. The sleeve barrel ous the new inner shaft for the lever. Also, what i thought was a washer on top of the dome cover turns out to be the red rubber seal in the kit. It was just that old, black, and hard. Lol

I'd appreciate you experienced guys to move to north Idaho so i wouldn't have to write so much lmao.

thanks again