64 Riviera fuel filter with return line

[5632]

What happens if I eliminate the fuel filter that has a return line to the fuel tank with a single outlet only?  I understand these were used on motors with air conditioning only.  I don't even understand what was the purpose of them or what the benefit was.

[NTX5467]

Some engine applications used the return-line filter and others did not.

 

Inside the filter is a drilled orifice that sends a certain amount of fuel back to the fuel tank, after the carb has all that it needs.  Used before the "three-line" fuel pumps and the return line, in later years.

 

Keeps fuel circulating in the system.  Which can also keep it cooler, which can decrease the possibility of vapor lock in some situations.

 

Some GM brands used such a system, but not universally.  Chrysler Corp did too, usually on some 4bbl HP engines.

 

IF GM or others put those more expensive items on the car, there's a reason they spent that money!  Find the correct filter and be done with it.

 

NTX5467

[5632]

I assume the rest of you don't know anything about Riviera's with A/C like I don't.  I see no purpose for a return line after anymore.

[JohnD1956]

Good assumption.  Can't speak for others but I have never had a 64 Riviera, thus no real life experience.  Also I don't have a 64 Service manual to look it up, so I'd rather not venture a guess and have it lead someone to an incorrect conclusion.  If you think you won't need it, then go with your own conclusion.  But we do know that cars with, and without,  AC have these lines today, so somewhere, somehow, they must have a benefit. 

Edited May 24, 2019 by JohnD1956 (see edit history)

[Bloo]

I guess if it doesn't vapor lock, then you don't need it.

 

Current Internet wisdom about vapor lock suggests this wouldn't help anyway. On the other hand, back in the 80s before we had the Internet, I added one of these Buick filters (and a return line) to a Ford and almost cured an aggressive vapor lock problem. It went from vapor locking even on cool days to only vapor locking if the outside temp was 98F or higher.

 

Can't you buy it anymore? If you can't, one from a carbureted Chrysler K-Car will substitute. It won't look right, but it will fit.

[Bill Stoneberg]

You can buy the, our local auto parts house has them.  Why change what the factory put in ?

 

 

 

[RivNut]

Buick only installed the return line on air conditioned cars.  For a reason.  Through testing and research.  I'm not one of those Buick engineers.  I just live with what they engineered. Probably even a better idea now that we're in the age of unleaded fuel. 

[5632]

Every ones views are helpful.  I just won't turn on the A/C even though my wife won't go with me when it hotter.

[Frank DuVal]

On 5/16/2019 at 11:37 PM, NTX5467 said:

Keeps fuel circulating in the system.  Which can also keep it cooler, which can decrease the possibility of vapor lock in some situations.

 

I saw NTX's reply and didn't think any more information was needed. Yes, return line was installed for vapor lock issues. 

 

You can go without it, but for what reason?, and be sure to plug the fuel line you are no longer using. If you develop problems you did not have before, then you will know why it is there!☺️

[RivNut]

On 5/27/2019 at 9:00 PM, 5632 said:

Every ones views are helpful.  I just won't turn on the A/C even though my wife won't go with me when it hotter.

If that's the case, then remove the condenser as well.  Not running the a/c doesnt improve the air flow through the radiator, that condenser is still blocking a lot of airflow.

[60FlatTop]

On 5/16/2019 at 11:37 PM, NTX5467 said:

IF GM or others put those more expensive items on the car, there's a reason they spent that money!  Find the correct filter and be done with it.

 

Read On A Clear Day You Can See General Motors . It will help answer a lot of similar questions.

[NTX5467]

I read the book when it came out I the earlier 1980s.  Plus the Lee Iacocca book which came out a year or so later.  MANY questions answered!  Great reading.  Then Lutz's book "GUTS", in the later times, pre and post-Daimler eras for Chrysler.d

 

In the DeLorean book, there's a chapter where he talks about when he was at Pontiac, specifically in the earlier 1960s.  For example, they'd done the '63 full-size cars and GM Financial approved their production//assembly costs.  So, for the '64 cars, being the good engineers they were, they did what they could to improve upon them at the same price/expense level.  Ample tire size, good interior fabrics for great wear/durability, and other thing which would lead to the cars coming back in on their first trade-in cycle and being in better shape than some other brands, thereby boosting trade-in values and motivating current Pontiac owners to buy another one.  So they went into the financial approval meeting feeling pretty good, UNTIL the GM Financial operatives said the cars cost too much and that they had to get "$25.00/unit OUT" of the car.  ONE month before production was to start!

 

So, they went back and juggled tire brands/models, removed some chrome trim and made it optional, juggled interior trim fabrics, and looked for other things they could delete without causing too much chaos in the procurement cycle at that late date.  Things which would be easy to change, enough so that the new cost targets were met.

 

When I discussed some of these things with my machine shop operative, who was a long time Chevy guy, he mentioned how one model year's interior would be "gone" after one year of ownership, yet the next model year's interior would wear like iron.  We had a '61 BelAir that needed driver's seat position repair in its second year of life, yet the '62 Impala wagon my uncle bought was much sturdier.

 

On the 2009-2005 Impalas, the base cars had a nice seat fabric, but didn't appear to be quite as durable as it might be.  BUT if you bought the upgraded split bench seat, THAT interior had the "wears like iron for 20+ years" velour fabric on it.  Put the "good stuff" in the optional equipment category, to cover the additional cost.  Which is why most of the former rent car Impalas had the split bench seat option!  About the only thing that'd "kill" that interior was a cigarette butt.

 

Not unlike the differences in the '77+ Caprice standard velour interior and that of the same year Pontiac Bonneville.  The Caprice was "heat seamed" whereas the Pontiac was "sewn".  Put the two bare fabrics side by side, same general look and color, but the Pontiac fabric was about twice as heavy, for $1.00/yd more money.  Again, "wore like iron for many decades."

 

As for the vapor return fuel filters?  Engineering could specify them for production, but if the money "got tight", that was one things what would be easy to delete and nobody would really know it was gone . . . UNTIL they had a vapor lock issue in certain weather conditions.  The dealers heard the complaints, Engineering might send out a TSB on some things to try, etc.  But those who mandated the production cost increase never heard any of this, as the people "in the field" got an ear full.  Then the next year, the vapor return system might return as other "space" was found in the production cost battle.  THEN, they probably discovered they could decrease production complexity by using a three-line fuel pump, putting the return feature more out of sight to inquiring eyes.

 

The fuel pump on my '77 Camaro 305 2bbl, factory a/c car, uses the same fuel pump as the '69 Z/28 302 (non-a/c) car.  The same '77 Camaro, but with a 350 4bbl factory a/c car, has the three-line fuel pump.  Same car platform, same options, different engines.  One got the three line pump and the other one didn't.  Both my friend and myself had added a few degrees of timing into the stock settings.  His would surge at the top of 2nd gear in a two-lane blacktop pass.  Mine didn't.  Somebody advised him to put the base timing back to stock, and it stopped doing that.

 

The engineers might design the powertrains to operate well in some very extreme heat situations, but only about 20% of buyers will ever see those conditions, so when push comes to shove on production costs, they might down-engineer things to be more correct for the other 80% of buyers who never see these conditions.  Making the deleted items a part of an option package.  Many scenarios of how that juggling/balancing act can happen!

 

NTX5467 

[5632]

I am not an engineer but I learned in the mid 50's I could stop having vapor locks by placing 2 cloths pins on the fuel line.  Later I started using electric fuel pumps and have never had a vapor lock.  I do live in Arizona where it gets very hot in the summer and when pulling up a hill a vapor lock can occur if you were not prepared.  

[old-tank]

Where did you place the clothespins?

[5632]

On the fuel line 2 to 4 inches from the carburetor.

[old-tank]

Vapor lock occurs on the suction side of the fuel pump so clothes pins in that location will have no effect.  

[NTX5467]

(Put clothespins on the bottom and sides of the fuel tank for added heat dissipation surface area?)

 

(Chrome plated fuel tanks for heat reflectivity?)