Wiper parking/door timing issue need assistance

[Joseph K.]

I am going to Altoona next week and I am having a problem with the wipers not parking before the door closes. It worked well before the air valve broke under the vent. The plastic shaft broke from the plunger. I ordered a new one from Zip and when I went to install it it fell apart as I took it out of the bag. I ordered a replacement that they would send me no charge. But after a day or so they sent me a email that it was back ordered. I then looked around and found that several of the vender's were out. Then Paragon came though and sent me one. I replaced it but it does not seem to work. When vacuum is applied to the center port it seems to always apply vacuum to the bottom port even if the valve is pushed to the bottom. Does any one know how this valve is to work. I think it is to release the vacuum to the bottom port when the button is pushed down. I have the hose from the dash connected to the middle port and hose to the actuator valve connected to the bottom port. Any description of the action of the valve is appreciated. I think the new valve is defective.

[Edward J.]

Re: Wiper parking/door timing issue need assistance

Joe the way the valve works there are two ports that work with vacuum and the 3rd one is a vent. So if you have a vacuum pump and the valve is in hand its a easy check and if not just use your mouth and suck on one port and push the button and should release.

I had a problem with my 72 wiper just catching the edge of the door when shuting, but it was a adjustment on the wiper linkage, your may very well be also. Also make sure the linkage is not worn badly this does happen and small adjust there is sometimes is not enough.

[Alan S.]

Re: Wiper parking/door timing issue need assistance

Hi Joe,
After you've checked the new valve using Edward's test be careful when you mount the valve in the wiper bay.
There's a bit of adjustment on the connection between the valve and the mounting bracket in the bay.
By keeping the valve down/away from the wiper arm you allow the wiper to be closer to 'park' before the valve sends the vacuum signal to close the wiper door. Thus hopefully, the wipers are completely clear before the door starts to close.
Just don't move the valve so far down that the wiper arm doesn't push the plunger far enough for the valve to send the signal.
Good Luck!
Regards,
Alan

[Joseph K.]

Re: Wiper parking/door timing issue need assistance

Thanks Allen and Ed,

Found part of the problem . I checked the valve with a vacuum pump and found out that the vent was not working. The new valve that I purchased from Paragon was defective. The vent port was plugged on the inside with poor quality control and would not allow the vacuum to be released/blocked when the plunger was pushed in. I took a small drill bit and placed it in vise grips and hand drilled the orifice out. I could feel it go though the plastic plug into the air chamber along the shaft. After I did that the middle port vented through the vent port when through the middle port. Hooked it all back up and the door works like it should. I tried my best to get the wipers to park but they just would not go all the way even with the door up. I elongated the ,adjusted the set screw on the wiper motor and oiled and greased all the moving parts. They come to rest just under the door and when the door closes it pinches the blades a little bit. I am just running out of time to play with them any more. The only thing I can think of doing is to pull the blades off and moving them down a notch, if they are like a ford. Do you know when you pull the blades off if the shaft has a singular notch or does it have several notches so that there is flexibility in the blade setting?


On Tuesday a rebuilt alternator is arriving from John Perkel Jr. It the correct alternator for my car!!! I have been looking for this alternator for 5 years. I stopped by his both in carllise this year and was sure that he was going to tell me what I knew that it was rare and I would be lucky to find it with a date that would work for a July car. But by luck he had one! I had checked in with his father several times without any luck. I will receive it just in time before I have to drive out on Thursday. I have to get back to work. Thanks for the help

[Terry M.]

Re: Wiper parking/door timing issue need assistance

Joe,
When adjusting the sweep of wiper blades on any car, but especially Corvettes with the hidden wipers, it is essential that the windshield be wet and the engine running. Friction from a dry windshield will alter the sweep and so will the lower voltage that is present with the car off. When judging operations it is common to find wipers that contact the windshield posts, especially on high speed, because the sweep was set with a dry windshield and/or on battery power.

[Alan S.]

Re: Wiper parking/door timing issue need assistance

Hi Joe,
Have you looked at the wiper adjustment page in the AIM?
I believe the use of screw 'A' on the side of the wiper arm affects the angle of the blade and thus just when the blade hits the stop mounted at the base of the windshield. Could the angle of the blades be hampering the ability of the arms to go to 'park' position?
In the 71 AIM it's UPC 1, Sheet D6 and UPC1, Sheet D8. Probably there or close by in your 69 AIM.
Regards,
Alan

[Joseph K.]

Re: Wiper parking/door timing issue need assistance

Thanks for the info. I used the procedure in the AIM and still no luck. I think Terry is partly right that the windshield has to be wet. I can't keep it wet and operate the controls. Thanks again I will take what I have on blade location and possibly taking a hit on on the blade location. Maybe it will not be noted. Still working on the accessory position of the key. Jim has some good info but still not there yet. Regards Joe