Author Topic: Difficulty Disassembling Smog Pump  (Read 511 times)

ZLP955

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Difficulty Disassembling Smog Pump
« on: November 03, 2018, 11:59:26 PM »
Saginaw smog pump with assembly date 05591S (Feb 24, 1969) for my 04A LOS car. Pump is seized solid, not sure if it's the vanes or one (or more) bearings that have seized.
Have read a lot of posts about disassembling these, so in I went.
Soaked entire pump in a pail of evaporust for one week - a lot of crud came out, but it did not free up. Four bolts holding the cast cover on came out, but the cover wouldn't separate from the aluminum pump body. So, back in fresh evaporust, this time for two weeks. Removed it yesterday, still not freed up and the rear cover is still stuck solid to the casing.
So - decision time. Have several options:
1 - try repeating the evaporust treatment, but 3 weeks soaking already?? Unlikely to free it IMO.
2 - shelve this pump and just use one of the others that I have (dated 71-72 but spin freely).
3 - keep trying to remove the back cover to get inside - online instructions explain how to address the bearings, so it's just separating the iron from the aluminum that's problematic.

Option 1 will make me a major shareholder in Evaporust, and Option 2, well, I just hate quitting. So, I'm leaning towards option 3. Just concerned that I might crack the cast aluminum trying to insert some type of tool to prise the end cover off, there is literally no gap whatsoever and the interface is likely heavily corroded inside. I haven't tried to remove the pressed-in alignment dowel pins, but some forums suggested that wasn't necessary. Blows from a rubber mallet have no effect.....
Any tips, suggestions, advice? Would soaking in a penetrating oil help?
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

Kelley W King

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Re: Difficulty Disassembling Smog Pump
« Reply #1 on: November 04, 2018, 12:34:52 AM »
Just an option 4,  evaporust is great but sometimes leaves a sticky goo behind. I would soak in lacquer thinner if there are no plastics you need to save. Then a metal hammer on the cast to vibrate parts. Most people gut them before use anyway plus you have spare parts if needed.
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z28z11

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Re: Difficulty Disassembling Smog Pump
« Reply #2 on: November 04, 2018, 12:59:32 AM »
I've considered this for a while, considering I've got 3 to rebuild. Have you read this article ?

http://www.superchevy.com/how-to/additional-tech/1504-how-to-de-vein-or-rebuild-your-gm-smog-pump/

I had the same difficulty in trying to remove the rear cover on one of mine: I quit before I felt like I was going to damage it. I wish ASL was still doing these - Don used to do an exceptional job with components and complete systems. I'd give him my 3 in a eye blink if he was doing them -

Regards,
Steve
1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

ko-lek-tor

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Re: Difficulty Disassembling Smog Pump
« Reply #3 on: November 04, 2018, 02:01:24 AM »
Best penetrating oil is 50-50 acetone-atf. Heat is your friend. Take one of your freed up pumps apart to get an idea how it comes apart & where things are hung up on the pump you want to use, kind of a trial run. I say this as this 69 pump you are probably being very gentle as not to damage in anyway, like pry marks, cracking , etc... it may take the coveted Ford tool (a big hammer) to persuade things?
James to strangers, Bentley to friends
1969 SS/RS 396 coupe Hugger Orange X22 712 bought in 79
1969 SS 350 coupe LeMans Blue 713 bought in 79(sold)
1969 307 4spd. coupe Daytona Yellow 711 bought in 85

ZLP955

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Re: Difficulty Disassembling Smog Pump
« Reply #4 on: November 04, 2018, 02:27:09 AM »
Thanks everyone for your suggestions. Steve, yes I have read that article (made me smile, surely you 'de-vein' a shrimp, and 'de-vane' a pump!) and also found a really good one over at a - shock, horror - Ford forum here: http://www.boss302.com/smf/index.php?topic=63283.0
That's one of the sources that says the alignment dowels don't have to come out, and does describe going carefully to separate the cast rear cover. Interestingly, the Ford 'thermactor' looks to be virtually identical to our first-gen smog pumps. Article is a great write-up with good reference pictures too.

Bentley yes I am definitely trying to avoid damage to the dated pump, and willing to take one of the later-dated units apart if need be. Did yours separate easily?
Pending any further suggestions, I will try soaking it in penetrant and if it still resists, a bit of heat and perhaps try to press out those dowels.
Thanks again.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

69Z28-RS

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Re: Difficulty Disassembling Smog Pump
« Reply #5 on: November 04, 2018, 04:12:39 AM »
1.  If you can find a suitable container that is "just large enough" for your pump, it shouldn't take too much evaporust.   Or solvent.. depending on direction you go.

2.  If the solution (evaporust or solvent) is kept WARM, it should work better.   I think 2 weeks is too long; I think 2 or 3 days should be more than sufficient if it's going to work.  If not, remove it, clean it.. and re insert it... even try 'shocking' it with a plastic hammer before you put it back in...?

Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
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ZLP955

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Re: Difficulty Disassembling Smog Pump
« Reply #6 on: November 04, 2018, 05:48:52 AM »
Gary, I hunted around the hardware store until I found a pail that was just big enough to fully immerse the entire pump without significant wasted volume. Still took $$ worth of evaporust - it's way more expensive down here, AU$90 (about US$65) for 5 litres. Got a few during a 20% off storewide sale, but still pricey.
The guy who wrote up the article on the Ford forum I linked to above suggested soaking for a week or more, and when the first week's soak had nil effect, I doubled it to two weeks, agitating the pump every day to keep the fluid moving around inside it. Temperature wasn't an issue, with our Spring weather giving daytime temps in the 90's..... have used an aquarium heater in winter before, but no need at the moment.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

PURESS

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Re: Difficulty Disassembling Smog Pump
« Reply #7 on: November 04, 2018, 01:44:18 PM »
no ideal if this would work..just looking up if there was an idea      https://www.youtube.com/watch?v=BAOL1njGVJo

Danzo

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Re: Difficulty Disassembling Smog Pump
« Reply #8 on: November 05, 2018, 12:07:43 AM »
Tim, just did mine. Take a punch and knock out the 2 dowels. The back cover should then come apart. If you need any help,let me know.
Doc 

ZLP955

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Re: Difficulty Disassembling Smog Pump
« Reply #9 on: November 05, 2018, 01:06:19 AM »
Doc, did you knock them out towards the rear, or towards the front? It may not make a difference but I expect the factory pressed them in from the rear......
I will soak the whole thing in the penetrating oil and then try removing the dowels.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

Danzo

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Re: Difficulty Disassembling Smog Pump
« Reply #10 on: November 05, 2018, 01:51:20 AM »
Towards the rear.

ZLP955

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Re: Difficulty Disassembling Smog Pump
« Reply #11 on: November 05, 2018, 06:40:19 AM »
Ok thanks.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

70z28lt1

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Re: Difficulty Disassembling Smog Pump
« Reply #12 on: November 05, 2018, 01:57:33 PM »
I have also found that mild heating helps the Evap-o-rust.  I have an old pressure cooker that I leave the vent open and turn on low.  Works good with the acetone-atf penetrating oil trick too, but I'm chicken and put the whole thing outside in case the internal thermostat goes bad and overheats and catches fire.

ZLP955

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Re: Difficulty Disassembling Smog Pump
« Reply #13 on: November 09, 2018, 09:14:37 AM »
OK so I now have the pump soaking in a 1:1 ratio mix of ATF and acetone.
Just wanting some advice from those who have used this mixture - how long to leave it, is it normal for the mixture to separate? (I stirred it up a couple of times already), and what do you do with the part once you take it out of the ATF/acetone; wipe down, rinse off, use a degreaser, or ??
Thanks in advance!
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-E/MP at Lions Dragstrip in Long Beach.

69Z28-RS

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Re: Difficulty Disassembling Smog Pump
« Reply #14 on: November 09, 2018, 04:09:07 PM »
I use kerosene and ATF and I don't think that separates...   The acetone you're using is probably trying to evaporate....?

You probably should keep the container closed up to prevent the acetone from evaporating; the thin solvent (acetone in your case) is basically a thinner and carrier for the ATF to get into tiny openings and lubricate with the aft...
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan