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Wax Pellet Actuator

mini_mull

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Anyone ever replaced the wax pellet actuator in their air cleaner? Is it a pain? I don't think mine is working because even with the engine warmed up the damper door in the air cleaner snorkel still looks almost all the way closed. I'm guessing I can only only get it from the dealer, so a part number would be handy, too. Thanks.
 
I've never actually had the necessity to replace one.

Been so long since I've had to deal with one (yay!) that I can't recall if the flapper door is supposed to hold a vacuum. You may want to bypass the temperature vacuum switch (what you are talking about) and make sure that the flapper works as designed once you remove that switch. Also going to want to make sure the flapper door itself isn't binding, etc. Should be able to suck on the hose and get it to open. Make sure the vacuum source for that switch is pulling vacuum as well, and not on the wrong port.

Likely the switch IS the problem, but just in case, never hurts to make sure nothing else is the cause. About any GM vehicle from the 80's will have that switch, if you want to buy new go ahead and try, if not, wrecking yard should have hundreds of those things. Might be called something like a THERMAC switch.
 
If it were me I'd just jam a BB in the vacuum line at the actuator (no chance of it getting sucked into anything) and don't worry about it. It would stay open all the time but I don't think that's a problem in the desert.:grin:


Dave
 
Mine doesn't have a vacuum line attatched, I think they must have changed it in '87. I see what you guys are talking about in the Haynes Manual, but it's a different setup than mine. Mine only has the wax pellet accuator that heats up and pushes the piston which moves the damper, no vacuum line. I already tried just wedging it open, but it takes forever for the engine to heat up, and my engine runs cool anyways so it tends to hesitate until the engine warms up some.
 
Any chance you can post a picture of what you are talking about, or anyone else?

I thought the TBI air cleaners were very similar to carbed....if the flapper opens the same amount as the carbed cleaners, that would seem to be a big distance for just a wax pellet to push.

I've never seen what you are describing, it would be interesting to see.
 
Thats what I did


chevy_addict said:
If it were me I'd just jam a BB in the vacuum line at the actuator It would stay open all the time but I don't think that's a problem in the desert.:grin:


Dave
 
dyeager535 said:
Any chance you can post a picture of what you are talking about, or anyone else?

I thought the TBI air cleaners were very similar to carbed....if the flapper opens the same amount as the carbed cleaners, that would seem to be a big distance for just a wax pellet to push.

I've never seen what you are describing, it would be interesting to see.

Never posted pics on a thread, here goes.


19756122_2216b_1.jpg


19756122_2215b_1.jpg


BTW, I just got my complete manual set for 1987 GMCs, if anyone needs specific info from it feel free to ask and I'll try to help. I don't have a scanner, but do have a digital camera.
 
OK, thanks, that helps. Same idea, different operation!

Haven't noticed any vehicles with that setup, so probably not going to be a ton of that design in the wrecking yard.

With that being a "newer" design, might get lucky and still be available from GM.
 
I hope so. Guess I'll make a trip to the dealer tomorrow. If anyone who does have one like this could tell me how much theirs opens and closes, I'd appreciate it. I'm not sure if they just all stink, or some actually work. I don't want to go to all the trouble to replace it only to find it doesn't work any better.
 
mini_mull said:
Mine doesn't have a vacuum line attatched, I think they must have changed it in '87. I see what you guys are talking about in the Haynes Manual, but it's a different setup than mine. Mine only has the wax pellet accuator that heats up and pushes the piston which moves the damper, no vacuum line. I already tried just wedging it open, but it takes forever for the engine to heat up, and my engine runs cool anyways so it tends to hesitate until the engine warms up some.

Ya I have the same prob on my 90. I ended up just wedging it open w/a small nail. I really waven't seen any problems with it always kept open but it really dosen't get that cold here.

Dan..
 
btolenti said:
Back to the top! Does anyone have a part number for this????

According to my GM service maual the whole air cleaner must be replaced. So that means a lot of $$$$$. I bet it's a dealer item only..
 
No prob's with smog. Just had it smoged this year. I just put the tube back on from the ex to the AC. The guy never checked the aircleaner =)
 
my only issue is that I need to go to a referee to have my TBI swap approved next time I need a SMOG check, and I think they will check this....
 
btolenti said:
my only issue is that I need to go to a referee to have my TBI swap approved next time I need a SMOG check, and I think they will check this....

Why do you need to have your TBI swap approved? I swaped out my TBI from stock to a turbo-City high flow TBI and it passed smog with no probs. Did you ever fail a smog check before?

Dan..
 
My truck came with a Carb. I swapped in a TBI system from a 87 onto my 86, so to get it approved, I need to see the referee. Gotta love California SMOG laws...
 
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