I think Tom may be on to something.  A large amount of sediment in the tank might be the reason for your occasional problem.  On a steep incline or on a long incline the gas flow might be restricted due to sediment moving around in the tank.  If that's not it then Frank pretty much touched on everything else.

My two cents.  Chet...

Quote from: Gary 30U on June 16, 2016, 12:14:25 AM
Carmen, When I first got my 30U, (which has the water pump) I would have problems with it belching water about every fee minutes. What I found is that I had a plugged radiator. If would build up pressure and when it would release and flow it would blow out around the cap. It was never hot as you could hold your finger in the radiator. Took the radiator out and had it flushed, took the water pump off and flushed out the engine block. You couldn't believe all the crap that came out. Anyway had the water pump rebuilt (which is a special story of it's own) and haven't had any problems since.

Gary, Good advise.  I flushed out my engine and radiator a couple of years back and got quite a lot of crap out.  The car has been running great ever since.   

Chet..

If he fills the radiator to the top it will shed water until it reaches its running capacity. After that there is no need to add water.  You know heat expands so if you look into the radiator when it's cold you will not see any coolent.  No need to add the coolent that's lost.   When running the radiator should feel hot at the top and cooler near the bottom.  Of course it shouldn't steam. 

Chet...

The thermal-syphon system works well even in very hot weather, you shouldn't need an additional water pump.  Are you having over heat issues.

Chet...

Quote from: dixchief on June 07, 2016, 11:58:35 AM
Is your 29 the same block as the later 30U ( has water pump)?
Seems it would be different since the 30U has a huge opening to accept the waterpump.
Any other major differences?
Richard

Hi Rich,

Here is a reprint from Tod's web site - Plymouth: The First Decade
For Model info:  http://www.ply33.com/Models/30-U/

The 1930 Model U Plymouths had an "all steel" body. Externally the most visible change is to a wide radiator shell much more in keeping with the industry standard.  The fuel gauge is moved from the top of the tank and put on the dash and becomes an electrical instrument. Hydraulic shock absorbers replace the earlier friction type.  There were many running changes during production of the 30-U. Early production had a vacuum tank fuel pump. This changed to a mechanical fuel pump and a water pump was added. There were three different types of wire wheels used with three different bolt patterns. Early wood wheels were de-mountable rims while the later wood wheels were removable.

Chet...

Thanks Rich,   

The board seems to be very quit these days hopefully everyone is out enjoying their cars.  As for my 29 no water pump Thermal-Syphon system.

Chet...

Hi John,

Beautiful car, very nice paint job.  Enjoy...

Chet...

Hi Ian,

Wish I can help with your questions but unfortunately I don't have a clue.  I do want to thank you for the pictures.  I plan to start the same process soon.  Unfortunately still working on honey do's since I retired.  Currently have 3 open building permits maybe get the porch one closed out in the next 2 weeks.  I'm hoping that I can get started on the car by mid summer.  So in a way you are blazing the trail for me.

Chet..

John,

Here is a picture of the gas tank from my 29.  My assumption is that it is original but who knows for sure.  Yes the gas gauge flange is wider and lower to the tank.



Chet...

Just a follow up to my last post.  Although I have used the electric pump for a number of years it isn't exactly problem free.  The pump is wired to my ignition switch so that when I turn off the motor it turns off the pump.  After shut down the carb will drip a little gas until the pressure subsides.   I have a Tillotson Carburetor on my 29 and while the engine is running, no drips.  My intention is to get a vacuum pump up and running and use the electric as a primer pump if necessary.   Unfortunately I haven't had time to get to it.  I think with any of these old carbs if you run the electric pump without modifying the float valve they will leak gas.  How much is directly proportional to how affective the float valve is at stopping the gas flow under pressure.  Probably preaching to the choir, sorry.

PS, can't substantiate this but I think in line pressure reducers will also affect gas line volume when set to max low setting.

Chet...

Quote from: unmuneco on February 22, 2016, 12:39:11 PM
Good Morning Gentlemen,

reading thru the post's I am having the same issue with my 28  ?

Any suggestions to which electric fuel pump I can purchased that works best ?

your suggestions are appreciated.

What kind of issues are you having?

If you plumb in an electric fuel pump most come in 12vdc.  If you are running 6vdc positive ground you can install an inverter that will change the 6vdc positive ground to 12 vdc negative ground.  The electric fuel pump can then be driven from your ignition switch. 

What you are looking for is the lowest pressure type you can find.  Since the old carbs are gravity feed from the vacuum pump.  Pressure over 2 psi may present a problem depending on how well your carburetor check valve works. I picked up one in Auto Zone that was designed for old car carburation.  Pressure was around 2 psi.  I also changed the check valve in my old carb from a solid steel pin to a rubber tipped pin that seals better.  Matched one up from some old carburetor parts laying around my garage.

PS the vacuum fuel pump is easy to restore.  Some use an electric pump just to prime the vacuum pump.  If we knew the problems you are having it would be easier to advise.

Chet...

Quote from: frankp on February 11, 2016, 08:40:17 AM

Please feel free to ask questions.  I believe that's the reason Chet established this in the first place - share knowledge and assist where we can.

frank

Frank, you are absolutely correct. !!!

Hi Rusty,

It's been quite a while since I took one of these pumps apart.    I have not tried to take the gear off.  I would have thought that a scroll pin or something would be holding the gear on.  I guess it is press fitted.
 
I don't recall the fingers your photo is showing.  I know the steel eccentric is the impeller for the pump and vacuum.  The fingers might help provide a cavity seal.  As for the two covers the screw alignment looks the same.., how about the other side of the plate ?  I wouldn't horn the chamber just clean it.  Horning might make the pump less effective.

My 2 cents.  Thanks for all the photos,

PS... Nice work.  You always come up with a creative way to fix a mechanical issue.

Chet...

You guys are dragging me back to my collage days.  I don't think the average Joe thought in these terms back in the day.  Interesting none the less. 

I must admit I never favored DC generators even back in the day when cars came with them.  When they worked they worked fine but when you had a problem it was usually a head scratcher.  I don't think I can add anything new except that there was mention of a frayed wire.., I was wondering if this might have caused some other less noticeable damage to the generator. 

Have you read the following:  Also a good read.

http://www.1948plymouth.info/SupportPages/PNWR_Reprint.pdf

Good luck,  Chet...

Quote from: Old Man on January 04, 2016, 03:47:28 PM
It finally hit! We have very little snow but it was 0 F this morning. Brrrrrrrrrrrr. (That's 18 below for me.) I did a cursory snow blowing just to keep ahead of it. Have fun in Florida. My 94 year old mother in law is down there for the Winter. But she says it's raining a lot?

Your mother-in-law is right on the money.  It's pouring as I type but it is still a long way from the cold weather happening up north.