Washer Pump Operation - 1974 C3

[Lee S.]

I'm getting down to the last few details in anticipation of Flight Judging here in Michigan next month. The last time I remember the washers working was about a year ago. Now, they don't. My car still has the off-white/faded pump. It seems the valves and diaphragm look OK... no tears or splits.

Now, the bubba in me deciced to take it apart by removing the entire pump assembly from the wiper motor. Lots of dried up yuck in there. Cleaned it all up and lubed with some white grease.

When I reassembled, it seemed the pump piston was operating yet no fluid comes out. Took it apart again and now I can't seem to get the pump gear in phase with the wiper motor lever. Makes a loud clacking sound.

Help!

[Jack H.]

Re: Washer Pump Operation - 1974 C3

(1) Your copy of the Chassis Service Manual should provide a photo of the correct 'phasing' of the kidney shaped drive gear on the rear of the washer pump's mounting plate.

(2) When the WSW motor drives the washer pump, you SHOULD hear a 'thwack, thwack, thwack' noise as the pump piston is periodically cocked and released.

(3) The 'death' of a WSW pump is (a) to let it go dry from disuse and lose its prime, and (b) disassemble the pump nozzle/valve from the pump piston without replacing the internal gaskets (fresh gaskets come with the generic pump rebuild kits from HELP and other sources).

(4) Once the WSW pump is properly rebuilt, a trick to getting it to start up is to FORCE prime it. Suck on the inlet hose to pull washer fluid up and fill the pipeline and block the end of the hose with your finger/thumb. Now, with a second piece of hose blow water into the pump's inlet to fill/prime the pump cylinder and pump valve cavity. You'll know you've got things right if water comes out of the outlet nozzles and does NOT dribble through the sides of the pump nozzle/valve/cylinder interface. With the pump freshly primed, quickly connect the intake hose.

When you get the pump working properly, remember this is something you'd like to periodically exercise during long storage periods to keep the pump internal components lubricated....

[Patrick H.]

Re: Washer Pump Operation - 1974 C3

Lee,

A couple of thoughts...

- take a mouthful of water, and use it to "blow" the water through the hoses. Start with the hose that leaves the pump and goes to the wipers. If the water goes through you're OK. Otherwise it's common for the tiny holes in the wipers to get clogged and you can use a pin to clean them.

- Once that works, take another mouthful of water and disconnect the tube as it leaves the washer fluid reservoir. Blow water through there and out the wipers. Check for copious leaking at the pump. Remember, water leaks out = air leaks in = no suction for the pump.

- check that the hose in the washer reservoir is also unclogged.

-Done with all that? Now consider using a TINY bit of Permatex Ultra black to "glue" the hose to the top of the fluid reservoir where the hose meets the plastic fitting on top. I had the same problem as you, and found out that just enough air leaked in at this junction to keep me from pulling water out of the reservoir and through the washer system.

Good luck. Thanks to Jack Humphrey for the "water blow/suck" idea.

Some degree of clacking is normal while the system is dry. Prime it as above and you may do fine.

Patrick

[Michael W.]

Re: Washer Pump Operation - 1974 C3

There is a hole in the drive gear and another hole in the cover that must be held in temporary alignment during assembly, IIRC. I think I used a drill bit on mine. This will reduce/eliminate the clacking sound.

[Lee S.]

Re: Washer Pump Operation - 1974 C3

Can you explain this further? I'm assuming that...
a) wiper motor is stopped in the park position
b) align the washer pump drive gear to the wiper motor lever as stated in your reply.

I think this is my first problem. I don't think the pin on the wiper motor lever is getting positioned to the inside of the cog wheel.

[Michael W.]

Re: Washer Pump Operation - 1974 C3

Lee,

I think you're right with your assumptions, but I'm not near my manuals right now. Jack H. is correct in stating there is information in the shop manual.

[Lee S.]

Re: C3 Heater Box Removal, 454 w/AC - Nevermind

The drill bit inserted through the pump housing and into the cog gear hole was a great tip! Reassembly was a snap. No loud clack, clack now. Like Jack H. said, "thwack, thwack, is ok." I think this is getting too technical for me.

Now to second problem... I primed the pump as described by Jack only to find the main washer hose is all dried out and cracked. A little electrical tape temporarialy cured this. Now I have a trickle of water from the pump outlet ports and leakage in between sections of the pump housing.

I got one of my kids to stop by Vette Products of MI today and pick up a Dr. Rebuild washer hose kit and a pump repair kit. I'll let the group know how this turns out over the weekend. Too tired tonight.

[Raymond W.]

Re: Washer Pump Repair

Lee,

I had a similar problem with my washer pump. I was able to complete my repair directly from responses to your post along with a few side bar conversations with Jack Humphrey. I ended up purchasing a washer repair kit from Auto Zone for $5.99. It included three "white" nozzle pieces, two o-rings, and a reservoir screen. At Jack's suggestion I lubricated my existing umbrella valves that were housed in my "yellowed" nozzle with WD-40 and installed only the new o-rings. The washer work just fine. Now all I need to do is to remember to keep the washer pump lubricated by using it ever once in a while.

[Jack H.]

Amen, Brother....Glad To Help!!!! *NM*

[Lee S.]

Re: Washer Pump Repair (ALL FIXED)

Thanks to all for your help and advice. Mike Ward's post on how to align the cog gear using a drill bit solved the first part of the problem. I followed Jack Humphrey's process to prime the system and got just a little squirt. Next, I replaced all of the hoses, blew compressed air through the wiper blade lines, and replaced the pump. I lubed the piston with some liquid car wash soap and primed the pump as previously noted. Everything works.
Again, thanks to all.