Chicago Dreis&Krump Box&Pan brake rebuild

[extropic]

I think the threaded rod approach is going to be successful.
A hollow plunger hydraulic cylinder would be a nice to add to your (I assume you have) Porta-Power gear and would make replacing those bushings very simple. The cylinders are pricey new but can be found for much less from the usual used tool sources. You'll find one useful when it's better to pull than to push.

Hollow Plunger Cylinders

 

[Firestopper]

Hi extropic,
The treaded press make good sense especially in keeping things aligned. No Porta-Power gear, but have used in the past. Very handy tool indeed.
I gotta say though, I'm very impressed on how tight these bushings are. Gonna keep an eye out for a preowned porta-power set.
Thanks for the input.

 

[Firestopper]

Well brethren, I'm pleased to report that the two stubborn bushings are out. Those things fought me all the way out and required some heat on the right's inside boss. I had a section of 3/4-10 all thread on hand, but after experiencing two failed attempts I took Greg's (f350ca) advice and purchased 3' of B7 3/4-16 plain, hardened washer and grade 8 high hex nut. I learned that threaded rod does not come in the same grades as bolts like grade 2,5,and 8. They have their own grade schedule , B7 rod is between a grade 5 and 8 in a bolt.
The good part of the story (besides getting those bushings out) is the original arbor or press tool was still employed with only a 2" deep threaded hole added for the rod to secure to. The second part of the tool was a section of 2.5" pipe sch.40 x 3.75" long faced off at both ends and the inside weld seem taken down 1/2" from one end. A piece of left over .750" CR bar was cut and used as an end plate.


After drilling the 1/2" hole on the endplate, I was hesitant to chuck up the holding bolt directly into the Bison so I split a small section of copper tubing to protect the jaws.

Indicated as close as possible and center drilled the bolt head to turn the square material between centers.
Here you can see the copper protecting the chuck jaws.

I saved the facing for later as I knew the setup was less than ideal. Turning between centers I took .060-.080" DOC until I had a round profile.
Then dialed in the OD of the pipe.I used a cheap live center for this operation as I had pretty good pressure securing the setup.

Once I had the OD, I took the setup apart and removed the 1/2" bolt. Re chucked, face what will be the inside and turned a shoulder to fit the ID of the pipe. I used a 1/2" bolt (hole) knowing that the possibility of the hole would be slightly off center with the turning method I used. I needed this tool to have a perfect centered pull when used. This allowed me to bore the hole to final diameter after the end cap was welded to the pipe.
Here you can see the area or the inner weld seem that was relieved for the cap to fit.

No way the .750" thick cap will deflect under pressure.


Tacked three 1/2"-3/4" (autogenous) with the TIG. For those who might not know, Autogenous is simply using heat with no filler rod. For this application, only enough weld to secure the end cap for final facing and boring.
Re indicated and faced the outside, then bored to final diameter.

Having used similar setup in the past, I knew the center hole would be slightly off but once bored to final diameter, everything was true.

After de-burring the outside the piece was flipped and a large drill was used to reach for de-burr/chamfer the inside.
200 rpm and done by feel.

Ready for use!

The arbor is now used from the inside and pipe sleeve on the outside to "draw out the bushings.
The set up: Inside

Outside.

Overall.

A liberal amount of anti-seize was applied on the threads to prevent galling.
BAM! Success!
I will never underestimate the removal of bushings again. I think installation will go well with the use of dry ice as Mike (FOMOGO) suggested. I have froze bearing races in the past prior to pressing with success but will defiantly use this to press in the new bushing
These are the old bushings, the tool worked very well without damage to said bushings.

Thanks for all the tips and tricks guys. I should have invested the time in building this tool from the get go. I'm always learning new lessons.
Turn and burn!
Thanks for stooping by,
Paco

 

[f350ca]

They put up a good fight but in the end you won.
Nice job on the puller.
Didn't realize they graded threaded rod diferently.

Greg

 

[Firestopper]

Thanks Greg, Your input was/is appreciated. Yeah, I always learn something new or relearn things I forgotten hahaha.
Paco

 

[Firestopper]

Spent a couple of hours prepping for paint. I hit most weldments with a 2" roll-loc 50 grit to knock off the large weld spatter left from the manufacturer. The appearance of the large weld beads, it clear they used a dual shield process resulting heavy spattering. I do the same thing on chassis when restoring a classic car. It really dolls up the frame after painting. I also hit any visible nicks from years of "kisses". The last dressing was done on the top clamp finger bar. This area is where the finger clamps bolt to. I plan on masking this prior to paint, otherwise chipping and flaking will result any time the fingers are slid and reclaimed.

After blasting took off layers of brushed on paint, I could not repaint without removing all those BB's. I also removed the burrs on the bores.

The inside was especially bad. You can still see some spatter in the overhead corner.

The edges where also sanded to soften them up. This will prevent chipping later.


This is the top clamp apron finger clamp bar (say that fast three times). This was heavily dinged up from years of clamping fingers.
No paint will be applied from the weld toe out. The edge required rework with the roll-loc to bring the corners back.

More cleaning on the top.


The hammer tone paint should blend in well in the end. Next up is to remove the ball oilers. I use from ear plugs to mask off any setscrew, ball oiler hole for painting. Last of the hot work will be to weld large nuts on the lower base for leveling bolts, then wait for a calm day to shoot some paint. I think I'll install the bushing prior to paint as well. Gonna shop for dry ice tomorrow.

Thanks for looking,
Paco

 

[Firestopper]

Picked up a 2 pound block of dry ice and chilled the four bushings for the main body. While chilling, I pulled the old ball oilers on the apron pivots and cleaned out the oil galleys. Also installed new ball oilers on the link adjusters and completed the last of the hot work prior to paint. Eight 5/8" nuts where welded to the base plate for leveling the machine.

The chill.

Used a small punch to drive out the ball, then tapped to 10-32.


Used a 3/8" nut as a spacer along with a washer to use the setup to pull the oilers.
With just a few turns, the oilers where pulled free.

The holes where cleaned out in preparation for the bushing install.
Used the same tool to drive in the new bushings. I failed to get a temp but they where cold and went in with light tapping.

I then used a 5/16" drill bit (same size as the oil hole to mark the center on the bushing. Used a 1/8" drill bit for the oil galley for future flushing.
A ball oiler will be installed after paint.

The new pivot pins fit nicely as do the larger pivot blocks.

Inside view of the left pivot block. A large washer then a snap ring will secure it from pulling out.

On the link adjusters, I used a counter bore to establish a landing for the new ball oilers.
!/4" hole before counter boring.

Used a cordless drill to create the flat landing for the oilers.

After:

I found these oilers on line from a John Deere supply guy on eBay. Only needed two this size but the deal was for 10.
They come with felt wicks that titrate the oil. I thought this was a cool idea.

Loaded the wicks in and used a small 8mm socket to tap in the oilers flat to the landings.

Looks good. These links never came with ball oilers originally. The original bushings where bronze and required 30W machine oil prior to using the machine. Obviously not always used as the old bushings where badly worn and sloppy.
The new Oilite bushings don't require oiling but this should keep wear particles flushed out preserving the bushings service span.

Lastly, the eight base plate holes where enlarged to 5/8" and nuts welded to serve as leveling feet.

This section is ready for paint.

I want to acknowledge the members whom help out with different ideas on removing/installing the stubborn bushings as well as the oil flush idea.
Thanks for your help guys.

Thanks to all who visit and leave feedback as well, my goal is to learn and grow every day.

Turn and burn!

Paco

 

[Firestopper]

I had to modify a roll cage job I did some time back. The gentleman had removed the doors when he brought his "77" FJ 40 to have the roll cage installed resulting in the door/s conflicting by about 3/16". This ate up about 1/2 the day leaving only a couple of hours to work on the brake as I had to mow the lawn as well.

More evidence of past abuse:
The cast iron top clamp levers had been repaired at some point in its life. Both where broken in different areas and brazed back together. It's apparent they used mild steel flat bar to repair the levers leaving a rough transition at the brazed joint. I ground down as much as I could to feather the transition but the areas needed some filler.

The right lever was repaired near the base of the link connection. The flat bar they used to replace the cast iron lever/handle was made from two pieces of 1/2" thick bar stock and welded down the middle on both sides. These handles originally all cast iron have a large counter weight (cast in one piece) to assist in rotation while lifting the heavy top clamp.

The second lever (left side) was repaired closer to the middle about where the counter weight would be.

Some filler was used to fill in the low areas for a smoother transition. Here you notice the right lever has a repaired ear as well (far right) at the link connection.

Sanded and ready for prime and paint. You can see the weld seam (right) down the middle (side) where the two pieces of flat bar where joined to make one thicker lever.

Masked, primed and painted. I choose black to hide paw prints and to match the rest of the link, pivot assembly already black.

A short day, but every little bit I get done gets me closer to completion.

Thanks for stopping by.

Paco

 

[f350ca]

That poor machine has had a life if hard knocks. Its going to seam like a holiday in your shop.

Greg

 

[Firestopper]

Yes it has Greg and it will have an easy life by comparison in its new home. Can you imagine what it must have taken to snap those cast iron levers, Whoa!! freaking savage animals.

Paco