Vacuum advance enlightenment

[Thomba48]

I have issued this question already in a wiper motor issue post. Where it actually didn't make a lot of sense.

 

There is obviously a linkage from the vacuum advance to the vacuum line coming out from  the carb. The connection was disconnected. As a matter of fact, the vacuum line from the carb was sealed. The car was running beautifully without any issues.

I stupidly connected that line, took away the seal and connected the metal line from the vacuum booster wit the tube going into the carb. The result, the car is now running really bad, acceleration was an issue. It felt like he wasn't getting any fuel or not enough fuel at some stages, there was total stuttering taking place etc.

 

Questions:

What is the vacuum booster actually doing? In theory of course I know that. But how can it be that a disconnected link worked out better than when the vacuum booster was actually linked to the vacuum line?

So, could you just drive always without the vacuum booster being connected?

Is the issue that I experienced - so vacuum booster connected, acceleration a real problem - maybe an indication that I have a problem with my cars vacuum performance?

 

 

thanks

Edited July 16, 2018 by Thomba48

[kencombs]

I believe you are referring to the wiper motor, not a vacuum brake booster.  But, in either case the symptoms you have discribed indicate a large vacuum leak somewhere between your intake manifold and the other end of the line.  the result is low intake vacuum and a very lean fuel mixture with the resulting poor performance.

[DJ194950]

To what are you naming a vacuum booster?

 

There is  a vacuum line (from the bottom of the carb.) to the vacuum advance on the distributor and most likely a different line off the intake but Not on the carburetor,  to work the vacuum operation of the convertible top mechanism. There is a vacuum line of the intake manifold to the vacuum wipers. Do not know if the two vacuum lines from the intake manifold to the top and windshield wipers uses the same connection or not, I do not have a convertible.

 

DJ

[Thomba48]

7 minutes ago, DJ194950 said:

To what are you naming a vacuum booster?

 

There is  a vacuum line (from the bottom of the carb.) to the vacuum advance on the distributor and most likely a different line off the intake but Not on the carburetor,  to work the vacuum operation of the convertible top mechanism. There is a vacuum line of the intake manifold to the vacuum wipers. Do not know if the two vacuum lines from the intake manifold to the top and windshield wipers uses the same connection or not, I do not have a convertible.

 

DJ

Sorry - my mistake. 

 

Yes. You are right. Vacuum line from the bottom of the carb to the vacuum advance on the distributor was not connected. Everything was fine. 

What is this link actually for. After all not being connected it worked fine.

 

Now, I have reconnected the line. And the apparent issue occured. So do I need that connection at all. I do ,however, also remember now that the vacuum line from the intake I have not sealed off, it is simply open as I have taken the wiper motor out. Could that be part of the problem?

Edited July 15, 2018 by Thomba48

[Thomba48]

1949 are not using a vacuum motor to operating the top. So there is one line out of the carb and one linkage out of the intake to the wiper. So I believe ?

Edited July 15, 2018 by Thomba48

[busycoupe]

If you have the vacuum port for the wiper motor open that is likely the cause of your problems.  Try plugging it to see if it makes a difference.

[Thomba48]

Ok

[DJ194950]

Ok, it sounds like the vacuum advance on the distributor is leaking vacuum causing problems with running.

At idle the vacuum should not have any effect as the should be none as the carb. vacuum port should be located in a position that is blocked off in the carb. So should have no effect whether hooked up or not at idle (500 rpm) . If it does there is something else going. If a good condition vacuum advance does not leak and as carb. vacuum increases it advances the timing to more before top dead center( spark in the cylinder happens earlier) If timing was set with the advance disconnected the timing must have been st to work without any advance.

The car can and will run Ok without it but wastes fuel and maximum performance and can cause overheating the water/motor if it is hot outside.

After the carb. is opened some it does get vacuum depending  on  speeds/loads etc.

 

Best of luck with the car it is nice, take your time with it and enjoy. Time to meet some other old car lovers where you live and ask for some positive help and encouragement!

[Mark D]

I thought at first you might be referring to one of these, but it seems you’ve got the answer. This is a trico vacuum booster. Used to supplement and correct for poor vacuum conditions. I’ve got this recently in one of the p15’s I bought and have started the install in my p15 conv to see if it will assist the top operation. 

 

 

Ps nice speaking with you this morning!

[Thomba48]

1 minute ago, Mark D said:

I thought at first you might be referring to one of these, but it seems you’ve got the answer. This is a trico vacuum booster. Used to supplement and correct for poor vacuum conditions. I’ve got this recently in one of the p15’s I bought and have started the install in my p15 conv to see if it will assist the top operation. 

 

 

Ps nice speaking with you this morning!

Mark - always great what you do with your cars and great to know you as a person ?

[greg g]

Yes, plug both vacuum lines and see if your car returns to running the way you felt was normal.  If good performance returns, see if the wipers work. The vacuum feed for the wipers is from the intake manifold.  This vacuum is at its highest at idle and constant cruise speed.  A leak in this line will cause a lean fuel air mixture which will cause poor running conditions.  The line from the carburetor to the distributor provides for timing advance needed for acceleration, going up hills, etc.  As you open the throttle vacuum through the carburetor increases. This vacuum signal is opposite of manifold vacuum, being lowest at idle and increasing as the throttle plate is open. You distributor has two advance mechanisms centrifugal weights that react to rpm, and the vacuum signal which anticipates the weight movement and provides for slightly earlier advance than the weights can provide. Your car can run just fine without the vacuum advance, but will be smoother and a bit more economically with the vacuum working correctly.  If the vacuum diaphragm is torn, this will cause air to enter the fuel leaning the mixture also.  Perhaps that was the reason yours was disabled.

 

So plug them both and see if it runs like it used to.  Then unplug the carb he and see what happens. If nothing changes, plug it back up and see what happens when you unplug the wiper feed.  Most cars with the wiper feed open will probably stall as the air being sucked in will make too lean of a mixture to run.

[Thomba48]

17 minutes ago, greg g said:

Yes, plug both vacuum lines and see if your car returns to running the way you felt was normal.  If good performance returns, see if the wipers work. The vacuum feed for the wipers is from the intake manifold.  This vacuum is at its highest at idle and constant cruise speed.  A leak in this line will cause a lean fuel air mixture which will cause poor running conditions.  The line from the carburetor to the distributor provides for timing advance needed for acceleration, going up hills, etc.  As you open the throttle vacuum through the carburetor increases. This vacuum signal is opposite of manifold vacuum, being lowest at idle and increasing as the throttle plate is open. You distributor has two advance mechanisms centrifugal weights that react to rpm, and the vacuum signal which anticipates the weight movement and provides for slightly earlier advance than the weights can provide. Your car can run just fine without the vacuum advance, but will be smoother and a bit more economically with the vacuum working correctly.  If the vacuum diaphragm is torn, this will cause air to enter the fuel leaning the mixture also.  Perhaps that was the reason yours was disabled.

 

So plug them both and see if it runs like it used to.  Then unplug the carb he and see what happens. If nothing changes, plug it back up and see what happens when you unplug the wiper feed.  Most cars with the wiper feed open will probably stall as the air being sucked in will make too lean of a mixture to run.

I learned a lot - again. ?

 

OK - 

 

On the plug approach shall I plug the carb linkage to the advance?

When unplugged than I obviously unplug it from the advance?

The latter option I have obviously done, as I unfortunately left the wiper feed open ? with exactly the result you indicated.

As the timing was set with the advanced unplugged do I have to work on the timing again?

 

I have also ordered a gauge to check the wiper feed vacuum pressure as the wiper motor isn't working at the moment. Which obviously could be caused by the inside being dry. I shall check that out later this week. 

 

thom

 

[greg g]

If you moved the timing to deal with the leak it will need to be reset with the vacuum leaks sealed.  Ironically, you can set it by attaching a vacuum gauge to the wiper source.  

 

There are a couple threads regarding lubricating the wiper motor with light machine oil or maybe it was brake fluid.  Search vacuum motor lubrication.

[Mark D]

Another use for NEATS foot oil.  The valves inside the wiper motor are leather.  I’ve restored two motors with this product.

[DrDoctor]

Mark D,

   I’ve also heard that Neatsfoot works with leather internal parts. However, I recently discovered (while I was getting ready to delve into my vacuum windshield wiper motor project), that not all Trico vacuum wiper motors utilized leather internally. The alternative material appears to be some type of rather dense canvas-type material with some type of coating thereon. Those internals on ours was so deteriorated that it’s difficult to determine exactly what it was, but if I had to render a guess—leather, very thin leather. I’m using the canvas material on the rebuild. And, if this turns out to be an exercise in futility—I’ll get a 6v motor from Mac’s, and fabricate the connecting bracketry to the car, connect the motor to the central pivot, and the rest is easy. Thx.

[Thomba48]

Thanks. I honestly have to admit that I have never - even in its German translation - have ever heard of the existance of an neatsfoot oil. I am now certainly wiser than before ?

[Mark D]

15 minutes ago, Thomba48 said:

Thanks. I honestly have to admit that I have never - even in its German translation - have ever heard of the existance of an neatsfoot oil. I am now certainly wiser than before ?

 

I knew this would be something that is a uniquely American product. So I included the wiki photo. 

[rallyace]

2 hours ago, Mark D said:

 

I knew this would be something that is a uniquely American product. So I included the wiki photo. 

Baseball glove conditioning oil is basically a form of neatsfoot oil.

[Thomba48]

Well, well, well. You won't believe me but I have never touched such a glove. More a rower and have never been particularly good with any kind of ball games ?

[Thomba48]

But the question - is this neatsfoot oil just better or essential. Because ATF oil I have available. And by the way, we are certainly only talking about a drop of oil. It is not a question of drowning everything with it :-)?

[DrDoctor]

Thom,

   You’re correct in that you don’t need a lot of lubricant (whichever product you choose to use). If you’re disassembling/reassembling the vacuum wiper motor, you only have to smear the lubricant in the well where the paddles swing, and the paddle-seals themselves. A drop on the pivot shaft, the park-seal, and any other moving components, is all that’s necessary.

   However, if you try to lubricate the vacuum wiper motor without disassembling/reassembling it, all you have to do is to put a hose on the vacuum fitting of the wiper motor, place the other end of the hose in small container of automatic transmission fluid, and move the actuator arm several times. That movement will draw in the ATF on the intake stroke, and then expel the excess on the return stroke. ATF is a thin lubricant, and possesses a rather high concentration of detergents that’ll cut the waxy crud inside of the vacuum wiper motor. And, unlike brake fluid, it won’t damage any painted surfaces in the event of inadvertent splashing of fluid during this process.

   If you decide to send the unit to “The Wiper Man” (his last name is Fikken) in up-state New York, his fee is $100 plus shipping both ways. He doesn’t sell parts, he only rebuilds units sent to him—if they’re re-buildable. He also states that post-war units are the best candidates for his service, and pre-war units—not so much.

   Another company sells parts, but they aren’t leather, they’re the tightly-woven canvas, and from what I’ve been able to garner from “too much research”, both materials were utilized in these motors.

   Best of luck on this, and I’m interested in how it turns out for you. Warmest regards to you . . .

 

PS — My father was assigned to post-war West Germany, and we lived there for several years. Great memories, great experience, great people, and great pastries!!! Regards . . . . .

[Thomba48]

Hi thank

2 minutes ago, DrDoctor said:

Thom,

   You’re correct in that you don’t need a lot of lubricant (whichever product you choose to use). If you’re disassembling/reassembling the vacuum wiper motor, you only have to smear the lubricant in the well where the paddles swing, and the paddle-seals themselves. A drop on the pivot shaft, the park-seal, and any other moving components, is all that’s necessary.

   However, if you try to lubricate the vacuum wiper motor without disassembling/reassembling it, all you have to do is to put a hose on the vacuum fitting of the wiper motor, place the other end of the hose in small container of automatic transmission fluid, and move the actuator arm several times. That movement will draw in the ATF on the intake stroke, and then expel the excess on the return stroke. ATF is a thin lubricant, and possesses a rather high concentration of detergents that’ll cut the waxy crud inside of the vacuum wiper motor. And, unlike brake fluid, it won’t damage any painted surfaces in the event of inadvertent splashing of fluid during this process.

   If you decide to send the unit to “The Wiper Man” (his last name is Fikken) in up-state New York, his fee is $100 plus shipping both ways. He doesn’t sell parts, he only rebuilds units sent to him—if they’re re-buildable. He also states that post-war units are the best candidates for his service, and pre-war units—not so much.

   Another company sells parts, but they aren’t leather, they’re the tightly-woven canvas, and from what I’ve been able to garner from “too much research”, both materials were utilized in these motors.

   Best of luck on this, and I’m interested in how it turns out for you. Warmest regards to you . . .

 

 

PS — My father was assigned to post-war West Germany, and we lived there for several years. Great memories, great experience, great people, and great pastries!!! Regards . . . . .

Thank you very much. Yes with the wiperman I am in contact already. Sending it forth and back to the US/ Germany shall be my last option to choose from. In regards to Germany - trust me the country has even become better. Less pre-war, post war minds, more open-minded, possibly even more kinder people in place ? thom

[Thomba48]

21 hours ago, greg g said:

If you moved the timing to deal with the leak it will need to be reset with the vacuum leaks sealed.  Ironically, you can set it by attaching a vacuum gauge to the wiper source.  

 

There are a couple threads regarding lubricating the wiper motor with light machine oil or maybe it was brake fluid.  Search vacuum motor lubrication.

 

 

So here the result

 

I used my pressure gauge for the first time. So from the intake vacuum line the pressure was around 18/19. So that, from what I read in other posts sounds good. I plugged this vacuum line, but left the advance vaccuum line connected with the carb one.

 

By the way, should I have tested the pressure coming out of the carb vacuum line also?

 

Anyway. With this set-up the car really did not drive "well" at all.

 

I then disconnected the advance connection to the carb vacuum line. Plugged the line coming out of carb. But left the line going into the advance open. The car drove reasonably well again.

 

What does that mean in your opinion., Should I change the vacuum advance? I actually looked around, does a vacuum advance really have to cost over 100$. Is there a cheaper option somewhere to be found?

[Merle Coggins]

The diaphragm in your vacuum advance unit has failed. You will need a new one, and yes they are expensive for these old Mopars. 

[greg g]

New advance assemblies are getting expensive. Did you do a reading at the intake withe the carb to vacuum disconnected, and plugged?  18/19 is a bit low,single carb set up should be 20/21, dual carb 17/19