Vacuum Source for Windshield Wiper Motor

[Howard Prout]

I am fairly sure that vacuum lines from both the manifold and the vacuum pump go to my wiper motor - at least there are vacuum lines from both sources going through the firewall. I haven't looked to see what happens on the passenger side of the firewall. The line from the vacuum pump only goes to the wiper motor. The metal tube from the intake manifold has a tee near its end with one side going to the wiper motor and the other to the power brake reservoir. The manifold vacuum is about 20"Hg under normal conditions whereas the vacuum pump creates anywhere from 10"Hg at idle to about 15"Hg at 2000 rpm (it is supposed to create 23-25"HG at 2000 rpm). I have put check valves in both lines going to the vacuum motor so they don't rob from each other. What I don't know is if at some point in time the manifold vacuum line was modified ( it doesn't look like it was) to include a tee to feed the wiper motor. When I bought the vehicle it did not have a vacuum pump in the oil pan (it does now) but the external plumbing for the vacuum pump was there including the check valve at the port on the block and a line to the wiper motor. So my question is, should there be one vacuum line or two to the vacuum motor?

[KULTULZ]

Mr. Prout,

I think that origionally there were two hookups to the wiper motor but a late TSB had them both tied into one connection. This also had something to do with the vacuum source for the washer motor.

Let me go back through my notes and I will get back to you.

There was a lengthly discussion here I think about a year ago on this same subject.

[GTE427]

Howard,

My vacuum lines for the wipers are set up as you described. A metal line from the intake just beneath the throttle shaft on the drivers side, routed toward the firewall, under the throttle linkage mounting plate (with a rubber hose for vibration) that ends at the rear of the intake with two ports. One port to the Booster, the second (pointed upward) to the passenger side firewall for the wiper motor. Looking at the image, you'll also see a black line laying on the firewall, that's for the missing vacuum pump. I have two vacuum lines to the wiper motor, from the pump and the intake manifold.

I haven't seen what happens at the wiper motor either, so I can't comment on that. But your engine compartment configuration matches my car.

[Howard Prout]

Thanks, Ken. That is exactly what my setup looks like. I tested my system this morning by first disconnecting one source and then the other and found that both do indeed feed the vacuum motor. I also found out that my vacuum pump wasn't doing what I thought it was so I will be replacing it afterall.

[GTE427]

I also found out that my vacuum pump wasn't doing what I thought it was so I will be replacing it afterall.

Howard, you are a determined man! Hopefully some day I'll installed a vacuum pump into my car. But for now it can wait. Good Luck attaining 23"HG!

Thanks for posting all this information.

[Howard Prout]

Howard, you are a determined man!

That's what happens when you are retired and the golf season is still a month away!

[KULTULZ]

This photo is from the TECH ARTICLE Section here-

[Howard Prout]

This photo is from the TECH ARTICLE Section here-

Thanks for the info. I looked for the article in the Tech section and didn't find it. Can you give the link to it? The "Attach vacuum line from engine" is unclear to me - does it mean from the vacuum pump or the manifold? From the vacuum pump makes the most sense otherwise why have it?

Also I'm wondering if there is a difference between the 352s and 430s in the vacuum supply to the wiper motor. I notice in the Shop Manual that the 352s vacuum at idle is 19-20"Hg while the 430s is 17-18"Hg. I realize this isn't much of a difference but is it enough for Ford to have installed different systems? The diagram you included is the same as Fig. 26 on page 10-27 of the 1959 Shop Manual. The Shop Manual seems to primarily address the 352s and not all differences for the 430s are noted. I'm wondering if this is another one of them? Given that Ken's 430 is configured the same as mine, it would seem likely that the '59 430s did in fact have two vacuum lines to the vacuum motor.

[KULTULZ]

I looked for the article in the Tech section and didn't find it. Can you give the link to it? The "Attach vacuum line from engine" is unclear to me - does it mean from the vacuum pump or the manifold? From the vacuum pump makes the most sense otherwise why have it?

Here is the link- http://www.squarebirds.org/wiper_motor.htm

I would assume, it would be a combination of both sources. The motor operates off of manifold (engine vacuum) normally and the vacuum pump comes in at low manifold vacuum.

Also I'm wondering if there is a difference between the 352s and 430s in the vacuum supply to the wiper motor. I notice in the Shop Manual that the 352s vacuum at idle is 19-20"Hg while the 430s is 17-18"Hg. I realize this isn't much of a difference but is it enough for Ford to have installed different systems? The diagram you included is the same as Fig. 26 on page 10-27 of the 1959 Shop Manual. The Shop Manual seems to primarily address the 352s and not all differences for the 430s are noted. I'm wondering if this is another one of them? Given that Ken's 430 is configured the same as mine, it would seem likely that the '59 430s did in fact have two vacuum lines to the vacuum motor.

The 352 used a dual stage fuel pump, the top section being a vacuum pump. The 430 could not use a two stage fuel pump due to it's location.

I am beginning to think (I can find no data to support this) that both vacuum sources are important as one is constantly in support of the other. The vacuum pump comes in strong @ 2000 rpm at where manifold vacuum begins to fall off. I am beginning to think the two stage fuel pump works in the same fashion.

I have a 58 MERC manual in front of me but there is no vacuum schematic of the system. There may have been a Vacuum Routing Manual in addition to the Shop Manual. There is also a supply signal for the washer system.

Also on your manual, it may be an early print and all of the 430 info may not have been posted until later prints. The 430 was a late option in 59.

Is the BIRD included in the FORD SHOP MANUAL or does it have its' own manual?

[Howard Prout]

Thanks for the link.

I would assume, it would be a combination of both sources. The motor operates off of manifold (engine vacuum) normally and the vacuum pump comes in at low manifold vacuum.

Yes, that's my guess as to way it is intended to work.

The 352 used a dual stage fuel pump, the top section being a vacuum pump. The 430 could not use a two stage fuel pump due to it's location.

Someone said in another post that the combo fuel/vacuum pump on the 352s had two vacuum ports, one for power brakes and the other for the wiper motor. If so, then the 352s may only need one vacuum line to the wiper motor.

Also on your manual, it may be an early print and all of the 430 info may not have been posted until later prints. The 430 was a late option in 59.

The copyright date in my Shop Manual is 1958 so it may not have included all the 430 info but it does include a section on the 430 engine.

Is the BIRD included in the FORD SHOP MANUAL or does it have its' own manual?

My Shop Manual is specific to the 1959 Thunderbird (see attachment).

[KULTULZ]

The Dual-Action fuel pump on the FE has an inlet and outlet fitting. The inlet ingests fresh air. The outlet goes directly to the wiper motor. The brake booster depends on engine vacuum only.

I believe (hard to say without vacuum diagram), the vacuum pump on the MEL has one line going to the motor along with a line from the manifold vacuum (tee for booster), to bypass the booster. They must combine somewheres in the cowl. The MEL pump ingests air from inside the crankcase.

[KULTULZ]

The Dual-Action fuel pump on the FE has an inlet and outlet fitting. The inlet ingests fresh air. The outlet goes directly to the wiper motor. The brake booster depends on engine vacuum only.

Let me clarify the above statement. The INLET port on the pump is connected to MANIFOLD VACUUM. This type of pump only supplies additional vacuum as needed as it senses (via the direct connection to manifold vacuum) manifold vacuum. If the vacuum source drops, it will begin supplying additional vacuum to the wipers.

The booster is supplied by direct manifold vacuum. The booster reservoir keeps a vacuum reserve for positive stops and as one applies the brakes, they lift off the accelerator pedal and the immediate manifold vacuum gain once again creates a vacuum in the booster reservoir.

[GTE427]

Howard,

I have a wiper motor I took from a 60 430 car. Looks different than the one posted on this thread with five ports total, bottom line is there is only one connection port for an incoming vacuum line and one port that must be an outlet port (shown as left open on the image attached by Kultulz)

I'll assume the two lines, one from manifold the other from the pump, must hit a tee (behing the dash) then continue to the motor connection.

When time allows, I'll get an image and consult theparts books to see if different wper motors are listed for different applications or years.

[GTE427]

The following pictures are of the wiper motor from a 60HT 430, built 12/59.

[Howard Prout]

Thanks for the info, Ken. If the time comes when I have to repair the wiper motor I'll find out what the connection arrangement is. In the meantime I won't lose any sleep over it. I tested my system and know that the vacuum motor works on vacuum from either source. One aspect of this arrangement I find odd is that Ford did not include check valves in the vacuum lines except at the port on the block for the vacuum pump, but maybe that is enough. As such, the two sources are always fighting each other. The volume through the intake manifold is much larger than from the vacuum pump on the 430s, so it would seem that the vacuum from the pump would be lost when the intake manifold vacuum is low - ie. during acceleration - just when it is needed. I put check valves in both vacuum lines leading to the vacuum motor so it always gets vacuum from the strongest source - which is usually the vacuum pump according to my gauges. The neat thing with the check valves is that the source with the highest vacuum opens the check valve in its line and closes the check valve in the other line. The feeds to my vacuum gauges are before the check valves so I always know how much vacuum is available from each source.