The Ford Barn

bigd1101 · 07-12-2022, 07:16 AM

Well folks, the guy who rebuilt the flathead was right. The PVC valve I installed was robbing the wipers of vacuum. I pulled the PVC hose off the "T" where is fed into the vacuum that fed the wipers, the power brakes, etc. and started the car up.......and sure enough, the wipers work like new, or at least new for a 70 year old car

and something here in NYS has to work for the yearly inspection.

My new problem is: How can I keep the PVC valve in place as they do serve a good purpose (debatable here I'm sure) and.....keep the proper vacuum to the wipers? Or is it an either/or?

Don

Bored&Stroked · 07-12-2022, 07:28 AM

You probably need a 'vacuum cannister' to store vacuum - with a one-way valve in the line. This way, the vacuum can be increased, but not decreased . . . which gives you some stored capacity.

With that said, if you're under load, the vacuum will drop, and the reservoir will get depleted - which is pretty much the issue with vacuum-based wipers in the first place.

The only way to solve that issue is to install some sort of add-on vacuum pump.

Juergen · 07-12-2022, 07:32 AM

The best step is to move the vacuum to another source. What year is your car? 70 year old implies a 50s car. Now if it was a 30s car, you could add a vacuum under the carb in addition to the vacuum port at the valves. Ford had some fuel pumps with a vacuum port in the 50s if I recall, but I don't know if they fit your car.

bigd1101 · 07-12-2022, 07:54 AM

Quote:

Originally Posted by Juergen

The best step is to move the vacuum to another source. What year is your car? 70 year old implies a 50s car. Now if it was a 30s car, you could add a vacuum under the carb in addition to the vacuum port at the valves. Ford had some fuel pumps with a vacuum port in the 50s if I recall, but I don't know if they fit your car.

53 Merc (pictured)

Merc Cruzer · 07-12-2022, 08:24 AM

bigd1101,

Good to hear you figured it out.

This prior post might provide an answer. Once installed, the Electro-vac will run the wipers, even when the car is not running. And it is period correct too:

https://www.fordbarn.com/forum/showt...72#post1236972

marko39 · 07-12-2022, 09:17 AM

Sponsored Links (Register now to hide all advertisements)

Do you have a dual action fuel pump?

pistonbroke · 07-12-2022, 09:20 AM

If you don't have one already get a stock duel diaphragm fuel pump. It will give you the added vacuum you need. After that add the carb spacer with a designated PVC port. I think you will be very happy with the results. Tim

bigd1101 · 07-12-2022, 09:44 AM

Maybe I just re-install the old block vent tube and scrap the PVC valve......at least to get it to pass NYS inspection.

Merc Cruzer · 07-12-2022, 10:39 AM

Quote:

Originally Posted by bigd1101

Maybe I just re-install the old block vent tube and scrap the PVC valve......at least to get it to pass NYS inspection.

Sounds like a plan.

Ken Henry · 07-12-2022, 01:18 PM

I had the same problem with the vacuum wipers on my 51 after going to PCV. My solution was the New Port Engineering electric motor. Works great as long as you are running 12V... Ken

Krylon32 · 07-12-2022, 02:25 PM

Another vote for Newport Engineering. I have them on my 40 and they work great.

SoCalCoupe · 07-12-2022, 08:11 PM

Quote:

Originally Posted by bigd1101

Well folks, the guy who rebuilt the flathead was right. The PVC valve I installed was robbing the wipers of vacuum. I pulled the PVC hose off the "T" where is fed into the vacuum that fed the wipers, the power brakes, etc. and started the car up.......and sure enough, the wipers work like new, or at least new for a 70 year old car

and something here in NYS has to work for the yearly inspection.

My new problem is: How can I keep the PVC valve in place as they do serve a good purpose (debatable here I'm sure) and.....keep the proper vacuum to the wipers? Or is it an either/or?

Don

Thanks for posting your resolution, very helpful.

07-12-2022, 07:16 AM	#1
bigd1101 Senior Member Join Date: Aug 2018 Location: Ithaca Posts: 345	Weak Wiper problem solved! Well folks, the guy who rebuilt the flathead was right. The PVC valve I installed was robbing the wipers of vacuum. I pulled the PVC hose off the "T" where is fed into the vacuum that fed the wipers, the power brakes, etc. and started the car up.......and sure enough, the wipers work like new, or at least new for a 70 year old car and something here in NYS has to work for the yearly inspection. My new problem is: How can I keep the PVC valve in place as they do serve a good purpose (debatable here I'm sure) and.....keep the proper vacuum to the wipers? Or is it an either/or? Don

07-12-2022, 07:28 AM	#2
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,110	Re: Weak Wiper problem solved! You probably need a 'vacuum cannister' to store vacuum - with a one-way valve in the line. This way, the vacuum can be increased, but not decreased . . . which gives you some stored capacity. With that said, if you're under load, the vacuum will drop, and the reservoir will get depleted - which is pretty much the issue with vacuum-based wipers in the first place. The only way to solve that issue is to install some sort of add-on vacuum pump.

07-12-2022, 07:32 AM	#3
Juergen Senior Member Join Date: May 2010 Posts: 503	Re: Weak Wiper problem solved! The best step is to move the vacuum to another source. What year is your car? 70 year old implies a 50s car. Now if it was a 30s car, you could add a vacuum under the carb in addition to the vacuum port at the valves. Ford had some fuel pumps with a vacuum port in the 50s if I recall, but I don't know if they fit your car.

07-12-2022, 08:24 AM	#5
Merc Cruzer Senior Member Join Date: Jul 2010 Location: Conifer, Colorado Posts: 2,430	Re: Weak Wiper problem solved! bigd1101, Good to hear you figured it out. This prior post might provide an answer. Once installed, the Electro-vac will run the wipers, even when the car is not running. And it is period correct too: https://www.fordbarn.com/forum/showt...72#post1236972

07-12-2022, 09:17 AM	#6
marko39 Senior Member Join Date: Oct 2016 Location: harpursville ny Posts: 1,048	Re: Weak Wiper problem solved! Sponsored Links (Register now to hide all advertisements) Do you have a dual action fuel pump?

07-12-2022, 09:20 AM	#7
pistonbroke Senior Member Join Date: Feb 2021 Location: Perry Mo. Posts: 491	Re: Weak Wiper problem solved! If you don't have one already get a stock duel diaphragm fuel pump. It will give you the added vacuum you need. After that add the carb spacer with a designated PVC port. I think you will be very happy with the results. Tim

07-12-2022, 09:44 AM	#8
bigd1101 Senior Member Join Date: Aug 2018 Location: Ithaca Posts: 345	Re: Weak Wiper problem solved! Maybe I just re-install the old block vent tube and scrap the PVC valve......at least to get it to pass NYS inspection.

07-12-2022, 01:18 PM	#10
Ken Henry Senior Member Join Date: Jul 2010 Location: Rochester, NY Posts: 266	Re: Weak Wiper problem solved! I had the same problem with the vacuum wipers on my 51 after going to PCV. My solution was the New Port Engineering electric motor. Works great as long as you are running 12V... Ken

07-12-2022, 02:25 PM	#11
Krylon32 Senior Member Join Date: May 2010 Posts: 4,509	Re: Weak Wiper problem solved! Another vote for Newport Engineering. I have them on my 40 and they work great.