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View Full Version : Avanti R1 fuel pump leaking out the top-revisited



sbca96
09-10-2006, 09:11 PM
EDIT : 7/27/09 - to update picture locations.

EDIT : 7/20/07 see new post

EDIT: Was "63 Avanti fuel leak ... returned ... HELP!!!!!!"

Looks like my Avanti has a hobby of leaking fuel. I solved the leaks
at the input and output of the fuel pump, the leak from the return
line, and the leak from the tank. Now its leaking fuel out the top of
the fuel pump itself. There is an odd brass fitting that goes into
the upper half of the housing, and has threads to hook up "something".
Any ideas what is supposed to go here, and why it didnt leak before?
I think I will just remove it, and plug it, but I thought I was see if
it is there for a reason (usually things are).

Tom

sbca96
09-11-2006, 12:08 AM
I went to Home Depot and bought a 1/8 square head pipe plug, slapped
some teflon tape on it, and plugged the stupid hole.

Here is what the fitting looks liek that was in the hole, with a thru
hole in it :

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/fitting_001a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/fitting_002a.jpg

Tom

gordr
09-11-2006, 02:32 AM
Tom, is your Avanti an R2?

Supercharged cars have a line that runs from the supercharger output port to the pressure dome on top of the fuel pump. What that does is adds supercharger pressure to the atmospheric pressure on the "air" side of the pump diaphragm. That ensures that fuel pump pressure always exceeds the ambient pressure within the carburetor fuel bowl.

Lacking that feature, fuel delivery to the carb could fall to zero under prolonged high-boost conditions. Can you say "melted pistons"?

If you have an R1 engine, plugging the fitting is OK. On an R2 or R3, it is critically important. (Whether the carb is in a pressure box, or pressurized via a bonnet doesn't matter; the supercharger pressure signal is present inside the float bowl, and the fuel pump HAS TO overcome that pressure in order to be able push fuel into the carb.)

Oops! Almost forgot to mention: if there is fuel leaking out of that fitting, which is on the "dry" side of the diaphragm, it tells me that your fuel pump diaphragm is shot, and you should be getting a new fuel pump sooner rather than later. Denied an escape path via the fitting, the fuel that seeps through the diaphragm is going to wind up the crankcase.

Hope this helps.

Gord Richmond, within Weasel range of the Alberta Badlands

sbca96
09-11-2006, 02:58 AM
No, its an R1, so I guess its not needed then.

Thanks for the input! This is ALL I needed to give me the reason to
dump this mechanical nightmare, & put on a trouble free electric one.
I wasnt planning on doing it this soon, but I dont see another choice.
I already have the pump (from my 60 Hawk), so I just have to figure
out where to install it. I put the Hawk's pump in the front, & never
had a problem. The fuel was leaking out WHILE it was sitting. I had
nothing but trouble with the Hawk, until I put on the electric pump.

UNLESS, there is a rebuild kit available for these? I notice that it
DOES come apart, whats the success percentage for rebuild, if possible?

Tom

sbca96
09-11-2006, 03:18 AM
Just checked Studebaker International :

1558925

1963-64 Lark, Hawk, & Avanti with Jet Thrust R-1 or R-2 engine ... 39.95 ea.

Since I JUST fixed the other fittings, I am tempted to keep the stock
pump, but what can I expect in rebuilding it?

Tom

Mike
09-11-2006, 05:17 AM
If the diaphragm is leaking, gas can leak into the crankcase, or out into your garage. Either is pretty dangerous. Remember it's gravity flow to the pump from the tank.
That looks like a fitting from a hardware store. It sounds like you have an R2 pump. It's the same as an R1, except the housing is tapped to connect the back side of the diaphragm to the supercharger volute, instead of having a vent hole to the atmosphere. If you plug the tapped hole you should open up the other one.
I think the pump rebuild kits that the suppliers, (at least T-Bolt & SI), sell come from "The Old Car Parts Cellar". The kits contain a diaphragm made of modern materials that will resist the fuel additives now in use. Some parts are of different design than the original; but should work well. My first kit came from "SI" without instructions, and I thought I had the wrong one! You should use the heavier spring, from the original diaphragm, rather than the light one in the kit; if you want stock fuel pressure.
I don't use Teflon tape on cars. It always seems to find its way into oil or gas lines, and makes it too easy to over tighten tapered fittings and crack housings. Teflon tape is for plumbers, like that fitting!
The stock "R" pumps are a little hard to find, and not hard to rebuild.
Mike M.

N8N
09-11-2006, 05:31 AM
The pumps are easy to rebuild, but I believe that you will need to find an R1 pump (or at least the top half of one) rather than just plug the hole in the R2 pump. The R1 pump has a different vent hole to allow the diaphragm to reference atmospheric pressure, which is not there on the R2 because of the supercharger. Alternately you could plug the hole *and* drill the vent but that sounds like a lot of work.

I wish I had a box full of fuel pumps and a digicam here so you could see what I'm talking about... the above probably doesn't make much sense without visual aids...

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
09-11-2006, 12:14 PM
Wow ... and I was all set to order the rebuild kit. Now I think its
less trouble to just add the electric fuel pump and forget about it.
Its no wonder they dumped this crap later.[xx(]

I dont know what to do. Wife gave me the OK to order the rebuild kit.

Tom

Roscomacaw
09-11-2006, 12:31 PM
Does she "OK" all your purchases?

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

CHAMP
09-11-2006, 12:34 PM
Over one year and 6,000 miles with no fuel pump problems with electric pump on my 48 Champion. That might be the way to go for you Tom? Just my two cents worth of advise :)BTW I still love those seats! They even look more comfortable[8D]

GARY H 2DR.SEDAN 48 STUDEBAKER CHAMPION NORTHEAST MD.

ROADRACELARK
09-11-2006, 12:58 PM
Tom,
If you're gona' "go electric", make sure you put the pump at the tank...they like to "push" rather than suck the fuel. Also, wire in an oil pressure cut-off switch for the obvious safety reasons.:)
Dan

[img=left]http://static.flickr.com/57/228744729_7aff5f0118_m.jpg[/img=left]
Road Racers turn left AND right.

Karl
09-11-2006, 04:37 PM
Tom . If you got gas comming out of that fitting. You got gas in the Oil!It will need to be changed also!

sbca96
09-11-2006, 05:22 PM
I JUST changed the freakin oil! Dammit, the bad news just keeps on
coming. I am swaying back and forth on electric vs mech pump. I JUST
got the fittings right, so I am tempted to fix the pump. How would I
have gotten an R2 fuel pump? It worked fine before, maybe I can just
put that fitting back in, with a line to it, that vents it down, that
way water can not get into it (probably what helped its demise). I'm
considering going for the kit, since I need headlight gaskets anyway.
I am waiting for word back from S.I. on the headlight gaskets. I am
not sure I want the can of worms of figuring out the return line deal
and how it will work with the electric pump. I have read that they
like to blow, and not suck, but the Avanti IS gravity fed pretty well.

Yes Biggs, it helps in a marriage if you run stuff past your wife.

Tom

N8N
09-11-2006, 06:00 PM
Actually the R2 pump should be fine - so long as you do NOT plug the hole in it, and the stem seal is in good shape. If the stem seal fails, you will blow oil all over your exhaust manifold with smoky results (or at least that's the experience I had with my '55 when I tried a '57 Golden Hawk pump "in a pinch") The vent passage in the R1 pump is a little more convoluted - y'see that little hole drilled crosswise through the casting at the very top of it, near the "stem" part of the pump? On an R1 pump, there's a vertical hole drilled up through the casting parallel to the stem to vent the diaphragm. That vertical hole is not present on an R2 pump. So to turn an R1 pump into an R2 pump, you should really put a small pipe plug in the bottom of that vent hole to make sure you get full boost referenced fuel pressure. Likewise, to turn an R2 pump into an R1 pump you should drill that vent passage, if you are going to plug the R2 boost reference line fitting hole. Of course, if you did either of these mods, you would have a "universal" R-series fuel pump, that could be used on either a supercharged or nonsupercharged engine just by judicious adding or removal of pipe plugs. I *think* the diaphragm spring is supposed to be different between the two, but when it comes to rebuild kits, you get what you get- I think they're all the same now.

...and here I am sounding like an authority on fuel pumps, when I'm the guys whose car sounds like it's about to blow a rod because the @%#$%^ fuel pump is so loud. Well, I know SOME stuff, anyway.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

N8N
09-11-2006, 06:02 PM
Oh, yeah, if you do go with an electric pump, you could either go to the later style inline filter with a return fitting on it and duplicate the later style return deal, or try to find a brass tee that would allow you to just keep it the way it is. The fuel pump goes near the tank, obviously.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

Mike
09-11-2006, 06:16 PM
The R1 pumps have a thick area where the fitting for an R2 boost reference pipe goes. It's easy to drill and tap to convert an R1 to an R2. You do have to plug the small atmospheric vent; but that's easy. I have an R1 pump I rebuilt and converted to use on my R2.
The stock Carter pumps are stamped with id #'s on the mounting flange. R1 = 3509S , R2 = 3508S .
Any atmospheric vent to the back side of the diaphragm will work fine. A tube to the fitting you have, bent so water, oil, or dirt stays out is a good idea. Some pumps have just a 1/16" hole drilled through the housing.
"Old Car Parts Cellar" is really "Antique Auto Parts Cellar" @:
http://www.then-now.com/The_Cellar/cellar.htm . See the five pages about the kits, there. He sells them direct; but he doesn't have headlight seals.
Mike M.

sbca96
09-11-2006, 07:13 PM
Well, I feel less worried now about reusing the R2? pump, the fitting
has a metered hole in it, though I dont know what size. Looked like it
might be about 1/16 to 3/32, if I was to guess. The price at S.I is
about the same as the "parts cellar" (shippings less at S.I.).

Does the "stem seal" come with the S.I. kit?

Tom

N8N
09-11-2006, 08:03 PM
The stem seal is part of the diaphragm assembly, so yes, it would be included. If I were a betting man, I'd say that that fitting you showed me was part of a gauge tubing kit, like for a nylon or copper tube with a compression fitting that would go to a mechanical oil pressure gauge. What would really be there for a R2 would be a fitting that was a male pipe thread on one side and a female flare on the other. The female flare fitting would have a steel line running almost up to the supercharger, and then a short length of rubber hose.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
09-11-2006, 11:54 PM
Nate .. sounds about right, who knows what has happened over the years
to a car thats 40+ years old?? I always thought it was strange that
it had extra belts, but I guess thats normal for an Avanti R1. No one
would have put a supercharger on a 3spd manual tran Avanti. I did go
and measure the hole in the funky fitting - its .093. It should be a
useable part with a tube attached bent down like I mentioned.

Tom

Mike
09-12-2006, 06:27 AM
You might want to make sure you have a genuine "R" pump before you order the kit. Some cars have been converted to modified Chrysler pumps. If it's off the car, verify the # on the flange. On the car, count the screws that hold it together. "R" series has 6 screws, Chrysler 8. "R" series is 3/8" bigger around.
All "R" pumps used the same internal parts, according to the late parts book.
The stock diaphragm assembly has the diaphragm spring and stem seal all staked together. The kits have only the bare stem staked to the diaphragm. You can salvage the spring from the old assembly, or use the lighter one that comes with the kit. The spring controls output pressure.
The kit stem seal is actually an "AC" part. As a hardware item, I think it's called a "rod seal". Early versions of the kits used a flat washer against it. Later versions have a formed washer that I like better. There's a lip that bottoms out against the housing and limits how much the edge of the seal is pinched. On an R1, The stem seal just keeps oil off the back side of the diaphragm. On an R2 it has to seal the boost reference, too.
Other parts in the kit are a little different, too. Hopefully SI will include the instructions from the manufacturer, which explain the differences. The kits are complete and easy to install.
Mike M.

sbca96
09-12-2006, 12:15 PM
Thank you all for your input, I will be referencing this page when I
tear into the pump. I didnt confirm it was a factory R pump, but its
bigger then the incorrect one on the R1 I just picked up. Hopefully
I didnt order the kit in vain, but the deeds done. S.I. got my order
for the pump kit and the headlight gaskets this morning. "Jim" over
there got back to me this morning confirming the part number for the
round headlight gaskets. He said they are playing "catchup" today, so
it might not get out today[V], I was hoping to get it fixed by Friday,
but I am not going to pay the 57 dollars shipping again.[B)]

Tom

N8N
09-12-2006, 01:01 PM
Mike was right on re: factory vs. aftermarket pumps; the factory ones have six screws and the aftermarket ones eight. I think Fairborn sells the kits for the aftermarket ones if that's what you have. There's nothing really wrong with the aftermarket ones unless you're doing a concours resto.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

JRoberts
09-13-2006, 06:09 PM
What is the easiest and/or best way to set up an oil pressure cut off switch to be used with an electric fuel pump?
Joe Roberts

N8N
09-13-2006, 06:17 PM
Joe,

it would be fairly easy to just use a pressure switch screwed into the head powering a typical Bosch fog light relay to cut out the fuel pump whenever you lost oil pressure. However, then you'd probably have to hide a pushbutton under the dash to "prime" the carb. for starting.

A more elegant solution that I've proposed before would be to use a Volkswagen fuel pump relay; it relies on sensing ignition pulses and also has a several second startup pressurization delay before it cuts out when it doesn't see an ignition pulse. (i.e. if you turn the key on, the pump runs for several seconds no matter what; then, if the engine is running, it keeps running, if it doesn't see ignition pulses it cuts out and then doesn't come back on again until it either sees an ignition pulse or the ignition switch is turned off then back on again.)

I can copy the pertinent sections out of an old Volkswagen Bentley manual for you and possibly even provide part numbers, but the downside is that the wiring diagrams are really "current diagrams" and are a little hard to follow for someone not used to reading German shop manuals.

I have not quite given up on my mechanical fuel pump yet, but just in the interest of making the mods to my car as "transparent" as possible (i.e. I don't want any "special instructions") if I do go to an electric fuel pump I will likely be working out the details of the VW fuel pump relay installation and then would be able to give you better info.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

Studebaker Johnny
09-13-2006, 07:12 PM
I rebuilt my 63 R2 fuel pump several years back. I believe the pump had a new diaphragm and several gaskets. Has worked fine since. Never was aware of a leak problem. However, now I notice a speed fluctuation running at high throttle in "Park" position. Also put in smaller jets and metering rods in carburetor because it was running too rich. Is the speed variation due to the fuel pump, carburetor, or supercharger?

sbca96
09-15-2006, 06:29 PM
I got the kit .. but a part is torn :

http://www.studebakerdriversclub.com/sdc_forum/topic.asp?TOPIC_ID=5884

Tom

1956 Hawk
09-15-2006, 07:32 PM
Johnny, what do you mean "high throttle in 'Park' position." From what you say I would first try richening the carb and see if that solves the problem. If that doesn't change anything I would check the ignition system.
David

sbca96
09-15-2006, 09:23 PM
OK .. here is what you get for your 40 bucks. Just FYI everyone. It
didnt come with any instructions either :

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/fuel_pump_kit_008.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/avanti_problems/fuel_pump_kit_009.jpg

Tom

N8N
09-15-2006, 09:46 PM
yup, that's the whole deal!

I *THINK* the directions are in the shop manual, but really, once you have it apart it's all self explanatory anyway.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
09-15-2006, 09:54 PM
I had the whole shop manual, but I can only find two of the binders.
Rear axle and the body one. Not much use. Mike M sent me them, so I
am set once I get a replacement stupid rubber thing.

Tom

gecoe
09-15-2006, 11:32 PM
Joe,

When I converted my car to an electric fuel pump I used an oil pressure safety switch for a Vega, Astra or Buick Starfire (GM part #3986857 or 25504803) to shut the pump off when there is no oil pressure. I found it on ebay for just under $5. I wired a chrome push-button switch in parallel to pump gas to the carb prior to starting when the car has been sitting for a while. I drilled a hole in the chrome delete button for the cigarette lighter and installed it in it. It sits right out in the open but blends is so well that it's hard to see.

Gerry
NE Colorado

Karl
09-16-2006, 01:49 AM
So what you are saying. Is you need a shop manual.I think I can help you out with that one.i have and extra original copy if you need it.as far as the lenze gaskets. cut them on the seam and reglue them.:)

sbca96
09-16-2006, 05:31 AM
Thanks for the offer on the shop manual, I just need to do a full on
search and I will find it. Its gotta be around here somewhere!! If I
cant find it, I will hit you up for your spare. You have to cut it?
SERIOUS?! That defeats the purpose of making it round.[B)] LOL!

Tom

N8N
09-16-2006, 12:15 PM
Well, I'm going to join you in the "frustrated by my mechanical fuel pump" category... I'd rebuilt a really, really trashy looking original R1 pump for my car - I take some sort of perverse pleasure in taking parts destined for the scrap heap and making them work again. Well I might have gone too far this time, the stem seal was leaking on this one. When I tipped it over a nice stream of oil came out the vent hole. Guess the only fix for that would be to have the casting sleeved. D'oh.

I put on a NO '55 fuel pump that I'd bought for the car before I went to R1 power, no more noise. I'm still no more clueful as to where my noise was coming from than I was before as I don't have a "known good" R-series pump to try, but at least it doesn't sound like a bucket of bolts. I'd almost be relieved if it was the fuel pump as I don't look forward to the prospect of changing the fuel pump cam.

nate

--
55 Commander Starlight
http://home.comcast.net/~njnagel

sbca96
07-20-2007, 12:22 PM
Well, as you all know I rebuilt my fuel pump & also my power steering
system - today was the shakedown drive of 55 miles. Looks like the
power steering held up "OK". The fuel pump however is leaking oil out
the top - AGAIN. What do you think of adding a vacuum line to vent
out the fumes. I think its just excessive blowby.

http://www.studebakerdriversclub.com/sdc_forum/topic.asp?TOPIC_ID=5982

Tom

Laemmle
07-20-2007, 04:16 PM
Mike fyi, Daves name is Thibeault...(pronounced T-B0);)


quote:Originally posted by Mike

If the diaphragm is leaking, gas can leak into the crankcase, or out into your garage. Either is pretty dangerous. Remember it's gravity flow to the pump from the tank.
That looks like a fitting from a hardware store. It sounds like you have an R2 pump. It's the same as an R1, except the housing is tapped to connect the back side of the diaphragm to the supercharger volute, instead of having a vent hole to the atmosphere. If you plug the tapped hole you should open up the other one.
I think the pump rebuild kits that the suppliers, (at least T-Bolt & SI), sell come from "The Old Car Parts Cellar". The kits contain a diaphragm made of modern materials that will resist the fuel additives now in use. Some parts are of different design than the original; but should work well. My first kit came from "SI" without instructions, and I thought I had the wrong one! You should use the heavier spring, from the original diaphragm, rather than the light one in the kit; if you want stock fuel pressure.
I don't use Teflon tape on cars. It always seems to find its way into oil or gas lines, and makes it too easy to over tighten tapered fittings and crack housings. Teflon tape is for plumbers, like that fitting!
The stock "R" pumps are a little hard to find, and not hard to rebuild.
Mike M.

sbca96
07-20-2007, 05:14 PM
I got all the stuff I need at lunch, gonna do the mod in the parking
lot at my work. I got a pipe thread to flare adapter to screw into
the top of the fuel pump, and a 2 or 3 foot long brake line to screw
into that and bring the vent up to the carb. Then I got vacuum line
to hook it to the carb. My thought is that the vacuum vent will draw
the blowby out of the top of the fuel pump (and maybe some oil) but
keep the front of my engine, frame and power steering parts free from
oil satuation until I can find the source (probably needs a rebuild).

I also think I will do an oil change and go back to 10W-30. I thought
I would try 20W-50 to raise the oil pressure, but it only helped when
the engine was cold - oil pressure is unchanged when warmed up. But I
think the thicker oil might be contributing to the oil being drawn in
to the engine through the fuel pump top seal. Thoughts?

Tom

N8N
07-20-2007, 07:40 PM
another idea would be to just disassemble the pump and put a dollop of Permatex No. 2 between the stem seal and the pump casting. I did that on my pump and it appears to be dry. But still knocking. The NOS '55 style pump started knocking too eventually, although when I gave it to JP to put on his '58 (also correct for that car) it was smooth 'n quiet. I don't get it.

nate

--
55 Commander Starlight
http://members.cox.net/njnagel

sbca96
07-21-2007, 06:45 AM
You forget Nate .. I already did that![V][B)]

Tom


quote:Originally posted by N8N

another idea would be to just disassemble the pump and put a dollop of Permatex No. 2 between the stem seal and the pump casting.

sbca96
07-22-2007, 01:11 AM
This is what I did, and it solved the leak. There was SO much oil
coming out of that vent, that it covered the frame and power steering
hoses!! I hate to say it, but I think an electric fuel pump is in my
not too distant future. I dont like worrying about this. I had one
on my Hawk for years without any issues, and I even mounted it up in
the front (rather than the rear like suggested).

After the 55 mile trip to work the pump, frame and steering were all
covered with oil, here is the same area after the trip back home, not
a drop of oil anywhere. Now the concern is that I am sucking oil in
to the engine instead![B)]

http://www.emperorjordan.com/sbca96/images/Avantinewimages/R1_fuel_pump_rebuild/modifications/VacuumVent/FuelPumpVent_001a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/R1_fuel_pump_rebuild/modifications/VacuumVent/FuelPumpVent_002a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/R1_fuel_pump_rebuild/modifications/VacuumVent/FuelPumpVent_003a.jpg

http://www.emperorjordan.com/sbca96/images/Avantinewimages/R1_fuel_pump_rebuild/modifications/VacuumVent/FuelPumpVent_004a.jpg

Tom