Hi all,

My wiper door will not open. I pulled the vacuum lines off of the actuator that is near the firewall on passenger side and when I connect a Mighty-Vac to the front port (closer to the bumper), I can pump a vacuum, but it slowly decays. When I connect to the rear port (closer to the firewall) it pumps and holds well.

I believe this means I need to replace the shaft boot inside of it (similar to the headlight actuator I just had to repair).

I need some help on how to remove that actuator. I removed the two mounting nuts that hold the actuator to the bracket. How do I remove the actuator from the rod that goes through the firewall? The part that is covered by a black boot and looks like it goes through the firewall looks like a long hex piece that is internally threaded? Then there looks like there is a jam nut as well. I backed off the jam nut and then I thought if I just rotate the actuator while holding that long hex piece, it would come off??? I try turning, but it doesn't move. I don't want to turn too hard as I'm afraid I will damage the internal diaphragm and then I will have to buy a new actuator!

Any help? Am I doing it wrong?

Thanks!

 

Pardon me, but I'll play devil's advocate here. If you have a good seal on the rear (toward the firewall), that is the side that pulls the wiper door open. The front (toward the bumper) closes the door. A small vacuum leak there is no big deal.

Are you sure the wiper door linkage is not froze?

 

Hi Dave - thanks for the input. I'm not sure of anything. I started with testing the actuator because it was easy

I figured I would fix that and if things still don't work, I would move on to the next easiest thing to check.

But you bring up a good point...maybe I should just move on. Right now, when I turn the switch on, the door doesn't come up and obviously the wipers don't move.

 

Go to Youtube & search for Corvette Wiper Actuator Repair. There are several great videos by a person who seems to know about these things. ( Hopkins? or something like that )Great info.

 

As for removing the system, it is not that difficult, just take lots of pictures. I had the same issue getting it out until I realized that the hex piece you are referring to is threaded inside on both ends but is reverse threaded on the opposite end (one end normal thread, the other backwards) Is is used to adjust the amount the rod comes out of the actuator. Leave it in place and just turn the hex and the two sides together will either tighten at the same time or loosen at the same time until it comes apart.
Pete

 

The answer to you issue is hidden in your statement above. When vacuum is applied to the rear port, and it holds the vacuum signal, THE WIPER DOOR RISES. If yours does not, the linkage is frozen or binding. My guess it is rusted inside the pivot points, between the nylon bushings. I have had pretty good success with a 50/50 mix of acetone and ATF. Just keep some in a squirt can and lather it on every couple of hours. It may take a couple of days to a week if it will free up.

Not true. If the rear of the actuator is holding vacuum, the rear seal is good. The reason your front is slowly leaking is because of the rubber plug in the front dead center. I use RTV and seal the plug closed for good. Just think, if the rear is holding, the internal diaphram is good, and then the only other possible leak in the front half would be the plug.

Another piece of advice. I try really hard to NOT remove the wiper door when I service anything underneath it. Normally simply removing the wiper grill will allow enough room to work if you are creative. You do not want to risk breaking off any of the 4 shoulder bolts holding the wiper door to the linkage. Those bolts are another periodic lubrication job for me.

Good luck my friend

 

That's how I got started! YOu are right, good videos...but he leaves out this little part. Or perhaps his came off super easy and of course everything I do on my car is never that easy!

So are you saying turn the hex with a wrench (and the actuator will turn with it) and then the actuator, the rod and the hex will all come out together?

- Thanks, this makes sense! Saved me $15!

So you are talking about the stationary piece with slats in it, right? Not the part that opens/closes. I was looking at that safety valve (in the event that is my next item to test) thinking about how I would get it out to test it and I was thinking of removing that slotted piece...looks like it's held down by ~8 small screws? Is that the same piece you recommend removing?

Thanks all!

 

Yes. Once you get the slotted piece (grill) off, you can try to raise the wiper door manually. With the vacuum hoses off the actuator, I put one hand to the back, and the other hand to the front of the door. Being gentle but firm, pull up and forward on the door. BE CAREFUL! If it will not come up without a fight, try lifting it up at the ends with a helper on one side and you on the other. Lift together. If it is too hard, stop and the linkage will have to be removed where it bolts to the firewall.

The safety valve does not need to be removed to be tested, but if the door will not raise with vacuum applied through the actuator your problem at this point is not the safety valve. That is for later

 

Thank you. I'm sorry, looking back at my original post, I realize that I failed to mention that when I pull vacuum on the "rear" port, the door comes up fine. I can also get it to raise by removing the black "plug" from the front of the actuator (bumper side) and pushing in with a screwdriver. So I don't think any linkages are rusted/stuck/binding/whatever. I think it's just a matter of not getting vacuum to the actuator.

 

Well then, never mind!

Your next test would be the safety valve and the wiper door relay.

Plug your vacuum gauge or mityvac into the rear vacuum hose from the actuator. Start the car, and see if you have a vacuum reading. Next, do the same with the front actuator hose. Then do the same with the override pulled out. Easy way to check for actuating vacuum.

 

Assuming your wiper mechanism isn't frozen, To open the wiper door manually, simply remove the rubber plug from the actuator & use a screw driver to press in on the actuator. I if the mechanism is frozen or moves with difficulty, remove the grill in front of the wiper door. I would then use WD-40 to free it up. Good luck

 

I just figured out a good way...after loosening the jam nut, back that jam nut all the way back toward the actuator until it runs out of threads. Then, you can put a wrench on the long hex piece to hold that steady and put a wrench on the jam nut and turn it...since it is out of threads, it will turn that whole shaft and not damage/put stress on the actuator internal diaphragm! Worked great. Now I'm going to get it media blasted and paint it.