View Full Version : R1 fuel pump rebuild proceedure - w/pics!

09-21-2006, 05:38 AM
Updating picture locations so I can show my dad all that I do here.
You guys are supposed to message me when you find the red x's.;)

Here is the disassembly proceedure for the R1 fuel pump, I will add
text where it will be helpful, but the pictures should be sufficent.
The stock Studebaker fuel pump is similar, so most of this will apply
to that unit as well. If you have dialup, this might be a little bit
for you, hit the red X or the "Stop" button on your browser. If you
want to see a certain picture, right click it, and hit "show". I am
using a rebuild kit from Studebaker International, with a different
stem seal that is included in the "Cellar" kit :

Here is the pump, off the car, and cleaned :




Closeup of the plug holding the pivot pin in :


Put in a vice (carefully) pinched on the "nose", and the plug hit with
a center punch a few times to make a ridge. The material is pretty
soft, I found that a screwdriver would "grind" it away :


I used a flat blade screwdriver and tapped around the edge, creating a
bump to pry against :


Again with the flat blade, I chiseled (by hand) material away to gain
better access to the plug, and get it out from under the "stake" :


Plug popped out. The plug has a MUCH longer tip on it, the one in the
kit is very stubby, and will allow the pin to move back & forth more.
I think I will tap the hole and modify a screw to plug the hole :


Pin comes out with a little cleaning of the hole :



Once the pin is out, the arm comes off :


Down inside the housing :


Remove the screws from the bottom :


Crack it open :



Was happy to find the diaphram cracked (needs replacement) :



Assembly slides out :


Apart :


New di

09-21-2006, 05:39 AM
Modifications : I decided to go through with the tapping of the plug
hole and creation of a filler screw, I started with a brass 5/16 pan
head screw 1/2 inch long :


Turns out the pin is .250 diameter and the minor diameter of a 5/16
tap is .257, since its aluminum - you dont have to enlarge it. I ran
the tap down approx. .250 inch :


Here is the screw, turned the head down to .380 diameter, removed all
but the first .250 of thread, shortened to leave some pin movement :


Cleaned up the seat with the dremel and a file :



Comparison between new theaded plug and original soft plug :


Comparison to the stumpy plug supplied with the S.I. kit :


Proper installation of the stem seal :



My fuel pump is actually an R2 pump, which is why it has that boss for
a 1/8 pipe fitting. The R1 has roughly a 3/16 diameter vent hole. I
didnt want to drill the housing, so I decided to make a vent that wont
allow water or dirt to get in (that easily). This is what I did :

1/8 male NPT to 1/8 female NPT 90 degree fitting from Home Depot, and
a square 1/8 NPT pipe plug :


Drilled the hole deeper in the plug, and screwed the pipe plug into
the 90 degree angle fitting to find out which "flat" faced down to
drill a hole to the center hole :


Hole goes through :


90 degree angle screwed into the housing :


Plug (which 3/16 through hole) screwed in - you can see the hole is
facing down and in.


Decided to label it for the next owner :



09-21-2006, 05:40 AM
I could just be like a Chiltons manual, and say "installation is the
reverse of removal" - but how often is that REALLY true??;)

Here is the correct way the valve goes together. I had to look at my
OWN picture above to make sure I had done it right![:I]


The mushroom shaped deal gets pounded in until its flush with the top
of the hole (or bottom), you CAN go too far - so dont!


I used Loctite in the hole, just a little bit. You dont need much :



Wipe off the excess :


Hammer it in. I used a wood block, that way I didnt harm my table, or
have to remove the fittings I just redid :


Make sure you put this gasket on correctly. If you do it right, you
can blow through the assembly, if you put it on 180 degrees, then you
will "seal" the input, and no gas will get through. Thats bad.



I used a VERY light film of permatex on both sides of the gasket, I am
paraniod about fuel leaks. After looking at the way the diaphram goes
together, I realized that I COULDNT use permatex there. If you cant
use it both spots, its pointless to use it at all. If I had to do it
over, I would NOT have used the permatex on the fuel bowl :





Then tighten the screws, I read that one thing to do to insure that it
doesnt leak after, you take the parts and use sandpaper or emery paper
and place it on a glass surface, then run the part back & forth until
you get a smooth uniform shiny part. I didnt want to do that since it
has a nice rough texture to the sealing surface, which seemed like it
would seal better then a smooth surface. Food for thought.


You can see what oozed out - even though I used a little bit!


Here is the stem seal installed on the old higher pressure spring :



Fits into the housing :


This picture is deceiving, I first thought it would go together better
if I did it this way, but the instructions say to put the arm on first.
They are right, if you push the top of the shaft through the housing
and then stick the "fork

09-21-2006, 08:40 AM
I'm at work, so I can't see your pics :( but just thought of something worth mentioning - when replacing the check valves, drive the mushroom-shaped metal bits in only far enough so that they are flush on the other side. I remember disassembling a "freshly rebuilt" R1/R2 pump once that wouldn't pump, only to find that the check valves were driven in all the way!

Also, you forgot the part about drilling out the seized screws holding it together, and also the scrubbing all the caked-on grease off with a toothbrush :/

As a side note, the screws holding the valve body to the bowl are the same on an R1/R2 pump as on a standard late V-8 pump. This is a Good Thing as I had to drill one out, and was unable to find a suitable replacement, even at the local fastener supply place that generally has everything.


55 Commander Starlight

09-21-2006, 12:23 PM
Luckily this pump "seemed" to have been rebuilt already, though the
kit used must have been a factory type. The housings were already
marked according to the shop manual - with a file. The screws inside
had the wear you would expect from someone trying to break them loose
with a blade not wide enough. It came apart rather easy. I bought a
set of stainless "allen" head screws from Home Depot which I got so I
would have them on hand IF I needed to replace one. Since it all
came apart so easy, I think I will pass on the new screws. I was going
to reuse the stock mushrooms, since they came out without damage. Do
you think it would be worth while to use some "Loctite" on them? I'm
also tempted to use a VERY light film of permatex on the gaskets when
I put it back together. I KNOW that the instructions say they will
seal just fine, but I have NEVER had anything I put together with No.2
leak on me ... and I HATE leaking fuel!![xx(]


09-21-2006, 02:48 PM
Tom; I noticed something about this 3508S pump that you have, it has been modified to an R2 by drilling & tapping a hole in the top cover for a Supercharger pressure equalizer tube. So:
(1) You want to check to see that the vent in top has been securely plugged.
(2) Be very carefull of that fitting, I wouldn't even think about removing it, as the cover is weak there, since it has no thick boss to support it!
I have an original factory equipment used one, that is a 3509S and it is an R1, no boss or hole.
Thanks for the great pictorial of the proceedure, I love it!

Studebakers Northwest
Ferndale, WA

09-21-2006, 03:16 PM
The 3508S pump was made for an R2. It has the housing drilled and tapped for the boost reference fitting, (1/8", NPT). It looks like the atmospheric vent is cast and partially drilled. You can see the small hole inside the housing, next to the recess for the spring.
The 3509S pump was made for an R1. I converted one for my R2. The boss for the boost reference was there, on the inside of the housing. The Chrysler pump, and others, have the boss too. It's more often on the outside of the pump. Marine applications require that the vent go to the engine air filter; and that's why it's there on most pumps. You don't want gas fumes in the bilges!
I tapped the atmospheric passage; and put a set screw in it from the inside as part of the R1 to R2 conversion.
Mike M.

09-21-2006, 03:27 PM
The fitting threaded into the 1/8 NPT has a .094 hole through it, my
plan was to leave it in, and add a bent tube to it, curving downward.
Is the .094 hole sufficient for the vent? Its been on the car this
way (no tube - just upward facing hole for crap to get in) for as long
as I have had the car. Who knows when the R2 pump was installed.

Also, I assume that the "Cellar" seal is installed with the metal side
against the spring, not the rubber side. The metal is tapered, & so
is the pocket for the spring/seal.



09-21-2006, 05:45 PM
Thanks Mike for the correction, I've seen so many of those Carters with the thick boss on the OUTSIDE, that I thought they were the only ones equipped to properly except the R2 fitting! Now that you mention it, I see in Tom's excellent Pics, the reinforced hole on the INSIDE of the housing top ! [^]

quote:Originally posted by Mike

The 3508S pump was made for an R2. It has the housing drilled and tapped for the boost reference fitting, (1/8", NPT). The boss for the boost reference was there, on the inside of the housing. The Chrysler pump, and others, have the boss too. It's more often on the outside of the pump. Mike M.

Studebakers Northwest
Ferndale, WA

09-21-2006, 06:06 PM
The fitting you have will probably be OK; but stock was a little bigger. The R1 vent passage is almost 3/16". I plugged mine with a 10-32 set screw. The Chrysler pump's vent is almost 1/4".
The R2 boost reference line is 1/4". The fitting on the pump is a 90 degree elbow, 1/8" NPT to 1/4" flared pipe. It's "Brass 1/4F 1/8M 90DEG P 9074805" at Advance Auto, for $1.88 .
The spring goes against the broad surface washer, and compresses the rubber until the edge of the washer bottoms out in the housing. That limits how much the rubber is squashed. I think the flat washer lets it get pinched too far.
Mike M.

09-21-2006, 06:18 PM
OK .. so as I show the stem seal in the picture above, is how it sits
in the pocket at the top of the fuel pump. Rubber against the housing
and the steel formed washer against the spring (which makes sense, the
spring would eat the rubber away in no time).


09-21-2006, 06:27 PM
Mike M.

09-21-2006, 06:40 PM
Now that I look at those pics, I need to take another look at the R1 fuel pump for my car. I don't know why it's leaking oil on top of the diaphragm; I was ASSuming that the stem seal sealed against the *bore* of the casting, but I now realize it's impossible for that to be the case. (I didn't disassemble it completely as I didn't feel motivated to knock the little aluminum plug out.)

Also, my old fuel pump that I put on that wasn't knocking... it's knocking just as loud as the R1 pump now. I am *this* close to just swapping to an electric pump, but I really don't have the $$ to buy a good one along with a regulator, nor the time to set everything up properly. Also I would still like to know WHY I am having this issue as I will be worried that something inside the engine is going to fly apart when I least expect it.


55 Commander Starlight

09-21-2006, 07:45 PM
You SURE its the fuel pump?? Have you tried isolating ALL accessories
by removing the belts and starting it? You will be amazed how quiet
a Studebaker becomes. Electric low pressure pumps are pretty cheap.
Maybe its a rocker, a lifter .. or ???


09-21-2006, 08:10 PM
Positive. When I remove the fuel pump and just run the engine on the residual gas in the carb the noise goes away completely.


55 Commander Starlight

09-22-2006, 02:40 AM
Bummer Nate ... dont know what to tell you - updated the "modified"
section above, now that you can the pics Nate .. what you think?


09-24-2006, 02:59 PM
Great tutorial and great pictures.
Thanks. Added this thread to my Favorites list.

[img=left]http://i82.photobucket.com/albums/j259/stude53/studesmall2.jpg[/img=left]Bob Feaganes (stude53)
53 Starliner Hardtop
Newton Grove, NC

09-24-2006, 07:02 PM
Looks good to me, I haven't had a chance to (and probably won't for a while) look at my own fuel pump yet, but I'll probably be calling your pics up if I see anything questionable...

I did take my car for a couple spins around the block today, I think I have most of the electrical stuff taken care of (still need to hook up the backup light switch and horn) and it actually runs pretty good... only issues that I can see are a) the fan (viscous drive) is too close to the shroud - which is odd, because I don't remember having an issue before - and the driveshaft issue that I've already mentioned. I got the speedo hooked up and working, but it reads fast because all I could find was a 3.31:1 pinion adapter. So I'm making *some* progress...


55 Commander Starlight

09-24-2006, 10:18 PM
Thanks Bob, Nate and Mike ... Updated the assembly portion, so guess
what I did today???:D


'63 Avanti, zinc plated drilled & slotted 03 Mustang Cobra 13" front disc/98 GT rear brakes, 03 Cobra 17" wheels, GM alt, 97 Z28 leather seats, soon: 97 Z28 T-56 6-spd, Ported heads w/SST full flow valves, 'R3' 276 cam, Edelbrock AFB Carb, GM HEI distributor, 8.8mm plug wires

09-26-2006, 04:57 PM
Tom, have you ever thought about putting this stuff in a blog? As you know, at some point your pics will not be accessible through this thread; and although I doubt I'll ever have use for them, probably lots of folks would benefit by referencing threads like these. Blogs are free, don't take any more work to do then these threads, and they'd be there for the future... you could do a thread here and ost the blog link; everyone could read the thread, and easily go to the blog if they choose. You could call it a Stude tech blog!

Food for thought...

Robert K. Andrews Owner- IoMT (Island of Misfit Toys!)
Parish, central NY 13131

09-26-2006, 10:54 PM

I am hosting the pictures on my FTP, so they will be around as long
as I have my FTP. I have had AOL for 10 years now, and dont have any
plans on switching. I thought about making a webpage for each of the
tech posts that I do, seats, fuel pump, & of course the Cobra brakes.
The pictures would still be hosted on my FTP though. As with the
Impala SS forum, its really up to the moderator to make a post like
this into a "sticky". The moderator could create an area of the Tech
Talk forum devoted to indepth posts such as this one. I have a post
on the Impala SS forum thats a "sticky" for changing a water pump seal
on the timing cover of the LT1. It requires a special tool. I figured
out a way to make the tool from a dry-erase marker. I made a drawing
for others to also make one. Its had a lot of traffic though it, and
even though I posted it a few years ago now, I still do get questions
from people that didnt read it all the way through.;)

As you can tell I put a lot of effort into this post, as I did the two
other posts I did on here I mentioned above. This was also a learning
experience for me, I have never rebuilt one before, and I got a LOT of
great help from Nate and Mike M. Thanks guys!:D


07-17-2009, 03:56 AM
Hi Tom, you said you replaced the spring with a high presure (the gold and white springs) you installed the gold spring.
If both springs are the same OD and the same wire size the one with the fewer coils will be the stronger spring.
It's like straightening out the spring in to one long bar the shorter bar will be harder to bend. thus stronger spring. I am a previous spring manufacturer.


07-17-2009, 02:15 PM
If you feel the need for an extra sealant on the diaphragm, Permatex Hylomar HPF would be a better choice. I used it on the pair of air horn gaskets on my R2 to eliminate seepage around the air horn to body interface. After 3200 miles of highway driving this spring, it has been 98% successful. On later disassembly, the Hylomar separates and cleans up quite nicely.

07-17-2009, 05:03 PM
Tom; over the several years, something has happened to your Pics! :(They are just little boxes again, and right clicking and choosing "view image" didn't work either.


07-17-2009, 05:07 PM
I can see all of them.....

Winston-Salem, NC
Visit The NEW Studebaker Skytop Registry website at: www.studebakerskytop.com

07-17-2009, 06:39 PM
Great tutorial. The pictures almost tell it all. Thanks.

07-17-2009, 08:54 PM
quote:Originally posted by r1lark

I can see all of them.....
Wow, what is emperorjordan? I thought it was a hacker site, with an aggressive name like that, so I have it blocked! That is what is trying to load, never heard of it. Are these not on PhotoBucket where everyone else's are?
Well unblocking the Emperor whoever he is, fixed it.


07-18-2009, 04:58 PM

I posted the above thread concerning this issue. AOL closed their FTP
last October, I needed a new place to store my pictures. Photobucket
and other free sites are blocked at most peoples Work, including mine,
and that was not an option. "Emperorjordan" is a domain of a friend of
mine, and he was nice enough to host all these Studebaker & GM brand
pictures even though he is a Ford guy! Nice of him huh?;)


07-21-2009, 01:55 AM
Very good job of presenting the process.
Question: I have worked on a number of R1's over the years and I have one in my shop right now. The return tube that vents all the way back to the tnk comes off the filter/sediment bowl that's plumbed into the fuel line just before the carb.
In your pictures it appears that the small brass 90 degree fitting stacked on the outlet side of the pump fitting is possibly the return fitting? If so is there a 0.040 orifice inside?
If it's the return it cannot be real effective in that location. You might want to investigate that part of your system. As vapor formation typically occurs right up on top of the engine where the heat soak is maximized.
Ken Michael

07-21-2009, 07:51 AM
The return line comes from a "T" at the fuel pump on early Avanti's. They use a sealed fuel filter on top of the engine, and no sediment bowl. Later Avanti's use the sediment bowl, with its internal filter, and a restricted port for the return line.
I think all the "Jet Thrust" Larks & Hawks used the sediment bowl.
I agree, it's better to return fuel from the highest point in the engine compartment.
Although the Stude manual says the purpose of the return is to cool the pump, considering the .040" restriction, it doesn't flow enough to do that. Similar setups by other manufacturers are called "vapor diverters". An important function is to allow pressure to the carb to bleed off when the engine is shut off.
Tom measured the restriction in the "T" for the return, on his early setup. Hopefully, he can tell us the size and where, exactly, it was.
Mike M.

07-21-2009, 01:17 PM
My question: If someone is building a non-R2 car from scratch and installing an R2 engine, and is concerned with function and not originality, what would be the ideal setup for the return line?

Robert (Bob) Andrews- on the IoMT (Island of Misfit Toys)
Parish, central NY 13131

07-21-2009, 05:06 PM
Don't know if this has been mentioned but I have never been successful at overhauling an R series pump with the new kits. The stem seal always leaks and fills the top of the diaphram with oil. Check yours after you put some miles on it.

07-21-2009, 11:17 PM
The higher in the engine compartment AND the closer to the carb fuel inlet the better. Use this as your design criteria and you'll be OK.
Ken Michael

07-21-2009, 11:32 PM
to handle our AZ heat and prevent vapor lock on ALL STUDEBAKER ENGINES here's how I do it. Under the hood, eliminate all heat soak items from the fuel system. Slow moving fuel will absorb gobs of heat if the external temp is very high, and vapor will result. ELIMINATE HEAT SOAK CAPABILITY. I remove the fuel pump and any/all other under hood items that can retain fuel.
Then I re-route the fule line up the firewall, and over to the carb inlet with a metal cannister fuel filter less than 4 inches from the carb inlet. Get it just as close as the air filter housing will allow. Use a filter with the return branch tube and plumb a return tube all the way back to the tank. DON'T SHORTCUT THIS ITEM. The rETURN FUEL MUST GO ALL THE WAY INTO THE TANK WHERE IT CAN BE RECOOLED BY THE BULK OF THE FUEL IN THE TANK. The tank itself is a huge heat exchanger and will reconvert any vapor back to liquid fuel.
Next put an electric pump somewhere near the tank to push fuel forwaard to the engine.
I put icing on the cake by putting "firesleeve" insulator material around the fuel supply tube and the fuel return tube for at least 3 feet down from the filter at the carb.
This system has withstood PHX heat of 113 degrees and sat idling with A/C on for as much as 30 minutes in 113 heat and has not vapor locked EVER under any circumstances. The water temp went to 240, it lost no water, and the A/C worked great.
You can cut corners if you like but if you want a system that works with todays fuels this is it.
See my website under Avanti R4004 for more details and photos.
Ken Michael

07-24-2009, 06:49 PM
Wow, this thread took off again. I have been busy with my dad visiting
from Michigan so I havent been here much. I lost the stock fitting so
I got the info from someone here I believe. I seem to remember having
to drill something out. Its been a while.

Yes, the pump seal IS leaking, and sucks oil into the top of the pump.
I have a tube into the fitting on the top of the pump to suck the oil
into the intake and keep it from coating the engine. Not the best way
to solve the problem, but it allowed me to drive the car home.[xx(]


07-24-2009, 06:52 PM
Might be on one of these threads :




07-27-2009, 02:28 AM
I had to do similar as kenmike2 twenty years ago with the 54 to avoid vapor lock. Now with the transplated bowtie 250 I still have the fuel recirculating. You would be surprised how easy it is to remove the filler neck steel pipe and weld in a fuel tight fitting.

If you car is ugly then it better be fast.....

65 2dr sedan
64 2dr sedan (Pinkie)
61 V8 Tcab
61 Tcab 20R powered
55 Commander Wagon
54 Champion Wagon
46 Gibson Model A
50 JD MC