Ok gents! I finally have a working washer pump again..... It was a bit of an ordeal. Strap in, this is a long one! Check the TL : DR and pics if you don't want to read the story version.
So as I last posted; the pump I received from LMC would not work. Basically when the wipers were cycling, it wasn't catching/moving the gear that engages the lever that plunges the diaphragm in the actual pump. After having learned a little more about how these pumps work, it may not actually be defective but just stuck in the position where the nub that catches the star gear on the motor can freewheel. Not sure, neither here nor there at the moment.
Yesterday I received the new pump from Rock Auto. Turns out they must source these pumps (which are Goodmark brand, they clearly state that on their website) from "The Parts Place", which I have purchased things from before. More for my old lady's '72 Cutlass than my truck. First two pictures are the pump's box once removed from the RockAuto box.
The RockAuto/Goodmark pump is functionally identical to the LMC pump. It does feel a little better put together than the LMC pump (it should, it cost about 1.5X as much) such as the plastic cover clips itself into place instead of having a chincy little piece of carboard that you have to stick between the electrical blades to keep the plastic cover on like on the LMC pump. Being functionally identical, it also mounts identically as in I have to use a longer screw with a spacer (also not included like with the LMC) instead of the two short screws on my original. The RA (RockAuto) pump also comes with a new plastic star gear for the motor, like the LMC.
So, I set about mounting this thing on my motor (already have the spacer/longer screw ready to go) without replacing the metal star gear on my motor with the plastic one, same as last time with the LMC pump. Get it on, turn on the motor and lo and behold! The pump starts moving like (I think) it should! Good deal! So I syphon the non-freeze style washer fluid up through the feed hose and connect it real fast (that s&$! tastes horrible..... tingles on my tongue too
). Turn the motor back on and hold the switch on..... pump is cycling. It takes some time but I can start to see it draw fluid through the top of the pump! before long it starts squirting out the output nozzles on the pump (I hadn't connected those hoses yet, figure it would be an easier prime without them connected as well)! Shut it down. Connect the nozzle hoses (all hoses, nozzles, washer bottle, filter in bottle, cap, mount are brand new.... my truck had none of this when I got it save for some very, very old/hard broken off pieces of original hose stuck in the cab grommets). Turn the switch back on and before long, BAM! We have fluid cycling on the windshield. Pretty stoked at this point. Notice that the driver side is throwing fluid up a little high and the passenger side is low. Shut her down. Take a small precision screwdriver and adjust up the nozzles. Turn it back on. Nice! Spraying right about where they should be. Ah... if only this were the end......
I release the washer button to let the pump mechanism cycle to where it (should) quit spraying fluid. Except it never does. I can hear the switch working whenever I push the knob in but no matter what..... it just keeps spraying!
So I take the cover off the pump and start taking a closer look. Can't seem to figure it out so I take the pump back off. Fool with it "on the bench" quite awhile and start to really understand how this whole mechanism ACTUALLY works..... (Disclaimer here. I'm sure most of you know, but it REALLY helps to actually understand how something actually works when working on it. Sometimes we can get away with not knowing.... like if this were a like for like swap from my old pump to new.... just swap them out and there you go, should work and I don't need to know how the actual pump/mechanism work. Not the case here). Once I understand how it works, I reinstall the pump and turn on the wiper motor to get it moving again. No more prime and I don't have the hoses connected at this point anyway, so no constant spraying of washer fluid. This is when I notice that although the nub on this pump is moving the lever that operates the pump diaphragm, it is moving the whole assembly just enough to operate the pump but NOT the gear mechanism that turns a full 360 then disengages the diaphragm lever from the sliding nub mechanism. Basically the arm is going back and forth but not back enough to catch the next tooth on the gear. This is/was the root of this issue with this pump (and probably the LMC pump) not working.
So I pull the pump back off. What makes the difference in stroke for that arm? The length that the lever nub is moved back and forth...... what controls that distance? The d@*$ star gear..... I grab the plastic star gear and actually hold it right in place with my metal gear on my motor (in my defense, they LOOK identical..... they weren't). Well Hunter757; you were right. The only way this "new style pump (and the LMC) were going to work were if I were to replace my motor's star gear.....
So, I give it the old college try, I have my entire dash mostly hollowed out at the moment so I have lots of room to work with a flat screw driver. I get under the actual base of the gear to do a little prying but that thing wouldn't budge. Not even a little. I gave enough force to make it move up (with shaft) from the motor some but it was not coming off the shaft. And I don't want to break my motor.
So what to do? Do I replace my motor with a new one? I don't even know if the replacement motors come with the slightly larger (the teeth are longer by about an 1/8" or so) gear already or not. Think about using a piece of rubber hose on the round nub on the new pump to make up the 1/8" difference. Decide that even if it's a tight fit, this will still eventual rub/come off due to being constantly under friction, even if slight, while the wipers are running (then again, I hardly ever drive my truck when I need wipers.).
I decide to go back to my old pump and reinvestigate now that I understand how these work a little better. I have realized that the pump switch just activates a small electromagnet that grabs the arm in to start turning the gear a full 360 degrees for the pump to work and then disconnect the system once it comes back around to the right spot. Turns out, everything on my original pump works mechanically fine!
I remount, resyphon, etc. but I don't get any luck here...... I then notice that the pump head is not staying mounted to the pump mechanism frame via the two screws like it should (this is a completely different design than the two newer style pumps, it's not a concern on them). Remove the pump and replace the original (I think) two sheet metal screws with machine screws that are longer and go through both the plastic pump body AND the metal frame a decent amount, put a couple of nuts on the bottom. Fixed and Done. (I actually replaced three of them this way as one of the others was feeling "stripy" in the plastic.) Remount, try again (essentially I wasn't getting enough stroke before this due to the pump head being out of the mount). Still no luck. Remove the pump, and reopen the pump head. I had checked it before and as I had mentioned in previous post, the parts LOOKED good but upon actually feeling them, I realized that the little parts inside were very tough. I took the pump head apart on the RA pump and the little inside rubber bits were MUCH softer.
I then made the decision..... I took the top half of the pump head that I knew worked for sure off the RA pump and mounted it on my old pump head's diaphragm housing. They were pretty much identical. I was still worried about this working though because my pump's diaphragm is almost certainly original (so over 50 years old). Reinstalled. By this point I had figured out a better, much less nasty tasting, way of bleeding the fluid to the pump: I turned on the washers, activated the pump while out of the truck and used my soft tipped air nozzle on the little hole on the washer jug cap (while holding it down) and forced just a slight bit of air into the system..... Works like a charm. The pressure forces a nice solid stream of fluid all the way to the pump (I have a brake bleeding tool that works similar to this; it adapts (or you make adapters out of spare master cylinder caps) to the master cylinder and forces fluid at pressure (about 25 psi) out of whatever bleeder you open while under pressure. Best d@*& brake bleeder I've ever seen.) Anyway, back on topic, it worked! I started getting squirts of fluid out my nozzle connections so I hooked them back up to the nozzle hoses, ran it through some more and all is good! It is not as strong as the RA pump was but it still works good and since I will probably never actually need to use it anyway, I am happy. What an ordeal! Check the two pics of the old mechanism with the new pump installed, with and without the plastic cover. Also my new washer fluid jug. Mine mounts on the core support and not the driver side fender. Mount holes were present and all.
TL;DR: I ended up using the top half of the new RockAuto pump head assembly on my old pump diaphragm housing and fixing a mounting issue with said pump head to mechanism frame.
So here are a couple of questions for you guys both for my curiosity and for others that may read through this thread having the same issues:
Can any of you confirm that your original washer motors (or anyone that has purchased a new/repo) have the plastic star gear?
Have any of you successfully removed the metal star gear and replaced it with the plastic one provided by these new repo pumps?
I will tell you all this; I am happy that I am able to retain my original pump mechanism. Not because of originality purposes (my truck is far from original) but because both of the repo pump mechanisms are VERY flimsy compared to my original mechanism, especially the electrical blade connectors. Don't get me wrong, I'm glad/grateful they're available. They just aren't built near as well/stout as my 50+ year old original.
Lastly: Hunter757 if you read this, sorry I can't help you out on the diaphragm sir. As you can see, I ended up still using mine in the end. I still think mine has some small cracks in it but it is obviously still serviceable. If you ever do come across where to buy a new diaphragm, I'd love to know!