Lloyd Posted June 7, 2020 Report Share Posted June 7, 2020 I've got my wiper motors working but the fuel pump I have installed is not one that has the vacuum pump on it. I have two of those pumps on the shelf but I don't know if either of them work. I tested the wiper motors by coming directly off intake vacuum. I'm thinking about installing a vacuum reservoir and piping it directly to the intake. The wiper motors look pretty bullet proof and there is no diaphragm but I'm wondering if the intake vacuum at an idle would be more than the wiper motors are rated for, also what would happen when I open the throttle plates? Wipers slow down?? Does anyone know how much vacuum the fuel pumps with the vacuum motor produce? Is there a way to test one of these fuel pump vacuum motors without installing it on the car? Has anyone tried running there wipers directly off the intake? Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 7, 2020 Report Share Posted June 7, 2020 A reservoir and a check valve, like later power brake boosters use, would resolve most of the issues with the throttle opening you mentioned. Capacity is another story, I think you'll find out the wipers won't wipe for long going this route. You can get rebuild kits for the fuel pumps or have them rebuilt. Or if you are running 12v you can go electric https://newportwipers.com/product/1939-dodge-and-plymouth-wiper-motor-replaces-factory-electric-wiper-motor/#wiper-motor Quote Link to comment Share on other sites More sharing options...
Lloyd Posted June 7, 2020 Author Report Share Posted June 7, 2020 No I’m 6 volt. You mean the fluctuations in manifold vacuum may end up depleting the reservoir if I was using the wipers? I had thought about that but figured power brakes came off the intake. Quote Link to comment Share on other sites More sharing options...
normanpitkin Posted June 7, 2020 Report Share Posted June 7, 2020 Fit 6 volt electric motor wiper from a chrysler 1 Quote Link to comment Share on other sites More sharing options...
Jim Saraceno Posted June 7, 2020 Report Share Posted June 7, 2020 My '35 Plymouth's wiper motors work directly from manifold pressure and yes, they slow down when you accelerate. Vacuum at idle is not a problem for these motors. Quote Link to comment Share on other sites More sharing options...
Lloyd Posted June 7, 2020 Author Report Share Posted June 7, 2020 Thanks Jim. I figured someone on here had done it, or tried it. Does the manifold vacuum ever drop so much they quit working? Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 7, 2020 Report Share Posted June 7, 2020 power brakes are not used continuously, so the reservoir is usually sufficient to hold enough vacuum that you don't see an issue. I would think that if intake manifold vacuum was adequate the OEM's would have done that, but I guess it all depends on what you are willing to put up with. The OEM's have to deal with overly picky customers. Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted June 7, 2020 Report Share Posted June 7, 2020 (edited) 1 hour ago, Lloyd said: Thanks Jim. I figured someone on here had done it, or tried it. Does the manifold vacuum ever drop so much they quit working? Yes, open the throttle to accelerate and the wipers stop on my P15.....so you back off to get a couple of swipes, and then resume accelerating. ? Or.....keep a good layer of RainX on the windshield. Edited June 7, 2020 by Sam Buchanan 2 Quote Link to comment Share on other sites More sharing options...
Los_Control Posted June 7, 2020 Report Share Posted June 7, 2020 4 hours ago, Lloyd said: Has anyone tried running there wipers directly off the intake? FWIW, that is how my truck is setup .... I am thinking from the factory. I can not tell you how well it works. I am not driving the truck yet, have no wiper blades installed until am ready to work on the wipers I just have the vacuum line plugged off. I imagine trucks more industrial farm use and they thought it was fine, while cars they would have the option for a vacuum pump? I am not sure how much rain you get in your neck of the woods, here on the west side is not much .... thinking off the manifold will work for me. Quote Link to comment Share on other sites More sharing options...
Lloyd Posted June 7, 2020 Author Report Share Posted June 7, 2020 22 minutes ago, Sam Buchanan said: Yes, open the throttle to accelerate and the wipers stop on my P15.....so you back off to get a couple of swipes, and then resume accelerating. ? Or.....keep a good layer of RainX on the windshield. Yuk. That’s not what I want. Thank you for answering that Sam. I’m curious what kind of set-up you have on your truck Los Control if you have the same Trico vacuum motors and if it goes straight from the intake to the wiper motors. But I would guess it probably isn’t factory. I think using the correct fuel pump would be the best bet. thanks everyone for your input. Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 7, 2020 Report Share Posted June 7, 2020 I thought about suggesting an electric vacuum pump, but the ones I've seen are 12v ones, so no go there. When I went 12v it took me awhile to figure out how to deal with the increased wiper speed. I ended up building a current limiting circuit to deal with it and it works, though I may have to reengineer it as it wipes somewhat slower than I want, it would be good for a low speed if I had a two speed setup. I might just set it up for a two speed wiper and be happy, should be doable. Quote Link to comment Share on other sites More sharing options...
Los_Control Posted June 7, 2020 Report Share Posted June 7, 2020 19 minutes ago, Lloyd said: I’m curious what kind of set-up you have on your truck Los Control if you have the same Trico vacuum motors and if it goes straight from the intake to the wiper motors. But I would guess it probably isn’t factory. Very possible it is not factory, I just assume it was and no reason to think they would do something different on the trucks. As far as the motor goes I do not know the brand name as I have not removed it "yet" When I get the floor back in and start working on the cab I will then. The way Sam explains the vacuum wipers operation is spot on, from my memories as a child and riding in the front seat listening to my father cuss about the wipers. One of the quirks about these old cars and what attracts me to them. Quote Link to comment Share on other sites More sharing options...
DonaldSmith Posted June 8, 2020 Report Share Posted June 8, 2020 The late Don Coatney put a vacuum reservoir on his Plymouth, with good results. Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted June 8, 2020 Report Share Posted June 8, 2020 You can see my reservoir in this picture, gives about 20 seconds of wiper action at full throttle. This was a worthwhile mod and is mostly hidden under my fresh air duct. I have since added a small 12v vacuum pump and that adds about 5-10 seconds of wiper action at full throttle. Reservoir and pump are out of a 1999-2010 Ford Superduty Diesel. Quote Link to comment Share on other sites More sharing options...
Sniper Posted June 9, 2020 Report Share Posted June 9, 2020 I see you are running headers, does the dual action pump interfere with them? Quote Link to comment Share on other sites More sharing options...
Adam H P15 D30 Posted June 9, 2020 Report Share Posted June 9, 2020 Mine is equipped with the standard single action pump but when I built the headers, I moved them far away from the block so a dual action pump would probably fit. Quote Link to comment Share on other sites More sharing options...
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