1955 olds vacuum lines - windshield wipers

[bbock]

I need a diagram of the vacuum lines for a 1955 olds 88 324 v8. I am having a problem getting the wipers to work right. The motor seems good but in order for the wipers to run, I have to disconnect one of the hoses. Any help would be great!!

[Oldsguy]

I don't have a diagram but which line are you removing? Maybe we can figure it out.

[bbock]

In order to get the wipers to oscillate, I have to remove the hose at the middle bottom of the wiper motor and I have to plug the open end. This hose goes directly to the fuel pump. I don't notice any engine change when I disconnect though. However I did plug the end of this hose while I took a short test drive. I believe that someone had the engine out or did some other work and had the hoses disconnected. I have just found where linkage to the throttle wasn't replaced correctly and would not let the trans go to passing function. I have a service manual which has everything BUT vacuum line diagrams

[Oldsguy]

Wow, that is a weird one. My guess is your guess is right, some previous owner bunged it up. I can't envision the hose going to the fuel pump. Maybe to a vacuum storage cannister. They are commonly used to hold vacuum created by the engine and are nothing more than a round, sealed metal can the size of say a frozen juice container or a little larger and they store vacuum for accessories when you stomp on the accelerator. Look for something like that on your firewall or inner fender and see if there are two nipples on it, one to the manifold vacuum and the other unused, that would be where your hose probably goes. As for the unused nipple on the fuel pump, I would say it would be pressure return line to vent the fuel tank, most cars have them. I say all this with a caveat because I very well could be wrong. I know the fuel pump is a pump and therefore might be able to create a vacuum that is used as plumbed, if that is the case then it might be a leaky/damaged pump. It may very well pump fuel but not create the vacuum needed. At any rate, good luck and let us know what you come up with.

[clloyd]

The fuel pump is a dual purpose fuel pump. It has a vacuum diaphragm on top to operate you wiper motor. I may be wrong but I think the nipple at the bottom center of the wiper motor is a breather to allow air in and out of the motor to reverse direction. My motor dosent have a hose on that position and they work fine. Take care

[clloyd]

On my 56 the fuel pump vacuum line is connected to the right rear of the wiper motor and the front is open.

[Oldsguy]

WoW! Now that is a new one for me but it makes sense. You learn something new every day............

[clloyd]

The 324 fuel pump has two vacuum lines that come out of the top. The fuel line comes out of the bottom. One vacuum line goes directly to the back of the wiper motor. The second goes to the vacuum block on the back of the carb to act as a booster and back up when your carb is not producing sufficient vacuum for the power brakes. If you have vacuum at both the top and bottom of the wiper motor then you are creating opposing forces and then it will just lock up. I don't know if you switch vacuum from the rear line to the front if that will cause the wiper motor to run back wards or not. I am going electric so I have a more stable wiper system. Take care