Smog Pump Restoration

[Edgemontvillage]

The smog / A.I.R. assembly was missing when I purchased my 1969 RS/Z project with the exception of the carrier bracket so I needed to locate suitable original parts. I sourced this rebuilt January 1969 dated smog pump some time ago however its functional and will need to be de-veined. The quality of the restoration is lacking, at least to my liking, so I searched for rebuild instructions on-line and couldn't find much. I thought I would create a thread on smog pump rebuilding for future CRG reference. There are threads on de-veining the internal pump-fan assembly however in order to do a comprehensive restoration the entire smog pump needs to be disassembled, the case restored and new bearings installed.





Dated 017 9 or January 17, 1969


Disassembly

The backing plate is secured by 4 bolts and once they are removed the plate can be carefully separated from the case. As the backing plate is cast iron and  uses 2 locating pins it requires some effort to remove, care is needed to separate it from the aluminum case to avoid damage.


With the backing plate removed, inside the case is a steel drum with plastic or Bakelite fan blades that are loaded on, and rotate around, a center shaft attached to the backing plate as shown. The blades need to be removed and are easily broken up with a few blows from a chisel and hammer. This is the common de-veining process. The broken blades can then be shaken out of the case. At the end of each plastic fan blade is a (sharp) metal scraper blade that also needs to be removed. Have a close look inside the drum for any remaining plastic bits and pieces.

Case-back removed


Internal drum with fan blades


De-veined


To remove the plastic cooling fan from the hub I used a plastic trim tool to access the back of the fan through a slot located in the top of the aluminum case. I rotated the fan 90 degrees tapped lightly and repeated until it was removed undamaged.

Plastic cooling fan


Slot in the top of the case where the trim tool can access the back of the fan


Tap the fan through the slot using the trim tool, rotating the fan occasionally until it separates from the hub, its a friction fit.


Once the plastic fan is removed the steel internal drum can be pressed out of the case via the extended tip of the drum (on the yellow graffiti mark). The fan hub will release from the tip as well.



There are 2 bearings in the smog pump, a needle bearing, style B248 1 1/2" ID x 1 7/8" OD x 1/2" width that is pressed into the access hole in the internal drum and another on the top or pulley end of the case, a sealed 6203LLBC3/EM radial ball bearing, 17 mm bore ID, 40 mm OD, 12 mm width.

The needle bearing is pressed out of the internal drum. Actually I pressed the bearing into the drum then fished it out with a pry tool. Easier than trying to pull it with a slide puller

Attempt to pull the needle bearing with a slide puller - not effective




Sealed radial bearing


At the top of the aluminum case is the sealed radial ball bearing that is retained by injected plastic. I was able to press this bearing out by supporting the bearing carrier on the top of the case then pressing the bushing out from the inside of the case. Care is needed as the case is aluminum and easily damaged. The injected plastic material has a low melting point so another (better) option is to heat the aluminum case around the bearing with a propane or MAPP gas torch before attempting to press it out. That will significantly ease the removal. 


Disassembled pump following cleanup


Re-Assembly

First, press the cooling fan back onto the hub, this can be done with a rubber mallet. I find it easier with the fan face-down so the hub seats flush against the table surface. The fan is fragile so care is needed. Its a simple friction fit so no adhesive is required. 





Next press the new needle bearing into the internal drum. As the drum is steel pressing the bearing in is straight forward. Once pressed in I packed the bearing with heavy duty wheel bearing grease.






Installing the a new radial sealed bearing into the case. First, I removed the original injection plastic with a Dremel grinding wheel then polished the mating surface with a Scotchbrite bit. This left two deep grooves.





The sealed bearing is semi-friction fit and requires a locking material to retain it in place. IMO this isn't a very good design, a bearing retainer ring like the one used for the main bearing in the alternator is easier to work with. I used J-B Weld epoxy that requires 15 hours curing time. I liberally filled the channels previously occupied by the injection plastic and pressed the new bearing in place then set the case aside for the epoxy to cure. 


Injection channels loaded with J-B Weld


The new bearing loaded from the inside of the case and pressed in. Very little force was needed.




Now the wait for the J-B Weld to cure


In the meantime a couple of small things to take care of, media blast and paint the backing plate (semi-gloss black) and re-plate the 4 bolts for the backing plate (clear zinc)




With the J-B Weld fully cured the next step is to press the internal drum tip onto the the sealed bearing. This is the most delicate step in the process as it stresses the bearing and the epoxy filler / adhesive. I supported the bearing edge and the bearing carrier surface of the case then pressed the drum tip through the center of the sealed bearing.



The fan hub is pressed onto the stem on the drum from the top of the case. The drum must be supported from the bottom and not allowed to "dangle" inside the case or the sealed bearing could be unseated.


The backing plate can now be reinstalled on the back of the case and secured with the newly re-plated bolts. Once the backing plate is secure the fan-hub should spin freely, if not the drum is likely binding on the back of the case and hasn't been pressed through the sealed bearing far enough. It will need to be adjusted.

Wheel bearing grease is added to the bearing contact surface.




Note the drum tip is fully extended through the fan hub.


The rebuilt smog pump with the pulley bolts and lock washers added

[x66 714]

Nice job Lloyd. You now have an oversize idler I did the same thing back in 1982 to my smog. What will you do for the rest of the system? What I did was use 5/16 clevis pins in the inj tubes. Remove the long tubes from the manifolds so the inj tube will have the correct height when threaded back into the manifold. No welding or gluing required. You can put a BB in the vacuum hose going to the deverter valve & you're done...Joe

[KevinW]

Lloyd, excellent write-up as usual!  I did this last year similarly, but my bearings were good, some cleaning and relube and good to go.  I did make a small puller with some bolts to remove the fan hub, worked well.   

[firstgenaddict]

Great write up Lloyd.
I rebuilt 3 at one time a couple of years ago -  I thought I would damage the case if I tried to press the sealed bearing out, glad to know that you found they would press out.
What I did in order to remove the front bonded bearing - I used a diamond wheel on a dremel and cut the bearing into 3-4 pieces removed it then ground the injected material out of the grooves in the same manner as you.
When grinding out the "plastic material" it smelled just like panel bond does when it is ground or cut - so I used automix panel bond - waited a day and then pressed the drum into the bearing.
In order to aid in retention I ground a very shallow(max .010-.015) concentric ring with a 1/8" wheel on a die grinder in a wave form around the outside of the new bearing (so it would intersect with two internal rings and then gooped up the internal rings just as shown. * probably overkill *

FWIW DEAD NUTS ON also sells a repro white fan -
https://www.deadnutson.com/smog-pump-fan/

Along with the pins and bolts for the case - although the case bolts are RBW not SBC. 
https://www.deadnutson.com/1968-71-smog-pump-housing-hardware-kit/

[Edgemontvillage]

Nice job Lloyd. You now have an oversize idler I did the same thing back in 1982 to my smog. What will you do for the rest of the system? What I did was use 5/16 clevis pins in the inj tubes. Remove the long tubes from the manifolds so the inj tube will have the correct height when threaded back into the manifold. No welding or gluing required. You can put a BB in the vacuum hose going to the deverter valve & you're done...Joe

Thanks Joe, I decided to plug the manifold inlets by tapping and plugging them with brass plugs, I borrowed this technique from Pacecarjeff who posts an instructional on his web site. The rest of the system I pieced together as I was able to locate parts. I sourced the tubes from Bill Hodel as he has the restoration and recoloring down to an art form. I like the BB trick to plug the hoses - I used that on my previous Z and it works well.

[rszmjt]

Very Nice job Lloyd.
I have done probably about 30 pumps & systems now, & I do things slightly different . I always tap the 2 cover alignment pins out first with a small pin punch, measuring the hite of the small 1 first, this allows the back cover plate to be rotated/wiggled, which helps tremendously to take pump apart, plus if the pumps are siezed up  you can wiggle & use penetrating spray to loosen up. I use a small steering wheel puller to take the front white fan & hub off as a assembly, I don’t like disturbing the plastic fan if it’s ok. If I do disturb/change the plastic white fan I always use a little epoxy or JB weld on the hub as I don’t like relying on just the plastic press fit on inner hub.
When I change the front plastic poured bearing I use a small torch to melt the OEM plastic out once I set it up in the press. I do the same as James did & groove the replacement brg OD with receiver grooves for the JB weld.
I set the internal drum on the press table and then press the outer housing with new bearing installed onto the inner drum using a appropriate size deep socket as a press tool, this allows you to wiggle & rotate the outer housing as you press to make sure nothing is in bind and also eliminates putting pressure on the outer bearing race/JB weld. Then I press the completed white fan/hub onto the assembly, this assembly procedure let’s you have a better feel IMO to avoid any binding issues. Finally I install the back cover/inner shaft assembly and bolts leaving them finger tight till the dowels are tapped/pressed back in.

On a recent Restoration where the exhaust manifold tube holes and internal threads were ugly is I used 1/8” tapered Allen pipe plugs to block the holes, instead of roofing nails or rivets in the smog rail tubes, this positively eliminates any leaks or sealing issues. Simply thread the manifolds from the outside and install the plugs leaving them proud .065 towards the outside, so smog rail tubes are tight & at the correct hite & not loose. Reason I did this was the manifold threads were a little compromised/ugly and we didn’t want to take a chance on them stripping when assembling. Hope this helps.

[rszmjt]

LOL - As I was typing my post yours came up, same sort of fix for manifolds . Cheers

[bcmiller]

Very nice Lloyd.

[z28z11]

Lloyd,

Nice thread - since I have three to do, I have a distinct feeling you had a hand in saving me a bunch of money. I have been looking for just such a tutorial for a long time, for sure. One question - where did you source the bearings ? I'd rather replace mine than trust 50 year old bearings (although they are likely made in the US) to renewed service -

Regards,
Steve

[Edgemontvillage]

Lloyd,

Nice thread - since I have three to do, I have a distinct feeling you had a hand in saving me a bunch of money. I have been looking for just such a tutorial for a long time, for sure. One question - where did you source the bearings ? I'd rather replace mine than trust 50 year old bearings (although they are likely made in the US) to renewed service -

Regards,
Steve

Thanks Steve, at the time of writing the bearings are available on Amazon, for the needle bearing search for "B248 Bearing", for the sealed case bearing search for "6203LLBC3/EM bearing", you'll find what you need. I agree with you - many guys will clean up the original, factory installed bearings, the sealed bearing can't be re-lubed so you're taking your chances with a 50+ year old parts. I also found the only way to clean and restore the case was to fully gut it. Good luck with your rebuilds.

[Edgemontvillage]

Very Nice job Lloyd.
I have done probably about 30 pumps & systems now, & I do things slightly different . I always tap the 2 cover alignment pins out first with a small pin punch, measuring the hite of the small 1 first, this allows the back cover plate to be rotated/wiggled, which helps tremendously to take pump apart, plus if the pumps are siezed up  you can wiggle & use penetrating spray to loosen up. I use a small steering wheel puller to take the front white fan & hub off as a assembly, I don’t like disturbing the plastic fan if it’s ok. If I do disturb/change the plastic white fan I always use a little epoxy or JB weld on the hub as I don’t like relying on just the plastic press fit on inner hub.
When I change the front plastic poured bearing I use a small torch to melt the OEM plastic out once I set it up in the press. I do the same as James did & groove the replacement brg OD with receiver grooves for the JB weld.
I set the internal drum on the press table and then press the outer housing with new bearing installed onto the inner drum using a appropriate size deep socket as a press tool, this allows you to wiggle & rotate the outer housing as you press to make sure nothing is in bind and also eliminates putting pressure on the outer bearing race/JB weld. Then I press the completed white fan/hub onto the assembly, this assembly procedure let’s you have a better feel IMO to avoid any binding issues. Finally I install the back cover/inner shaft assembly and bolts leaving them finger tight till the dowels are tapped/pressed back in.

On a recent Restoration where the exhaust manifold tube holes and internal threads were ugly is I used 1/8” tapered Allen pipe plugs to block the holes, instead of roofing nails or rivets in the smog rail tubes, this positively eliminates any leaks or sealing issues. Simply thread the manifolds from the outside and install the plugs leaving them proud .065 towards the outside, so smog rail tubes are tight & at the correct hite & not loose. Reason I did this was the manifold threads were a little compromised/ugly and we didn’t want to take a chance on them stripping when assembling. Hope this helps.

Mike, thanks for the feedback and importantly thanks for adding your experience and expertise on these smog pump rebuilds to the thread. As you pointed out and I referenced in the thread, heating the bearing carrier would ease removal of the sealed bearing a great deal. The injection plastic has a low melting point and pressing the bearing out of the aluminum case was "sketchy" no matter how well its supported. I also like your suggestions on the re-assembly process.   

[x66 714]

Here's what I was talking about with clevis pins. First of all they're 1/4" & not 5/16 as I mentioned earlier. When tightened into the exhaust manifold, they make their own seat...Joe

[169INDY]

Great Share Everyone!

JIM

[Edgemontvillage]

James & Mike, as the original sealed bearings had plastic injection grooves cut in them your suggestion to do the same or similar with the replacement sealed bearing would add a measure of surface area and therefore strength to the epoxy bond.

[bobs69z]

Excellent info....Thanks for write up  Bob