making an adjustable brake pedal pushrod

Hi folks!
been of the radar for some time, anyways, got a booster from a 94 f150 and a manual pedal box from the same truck, got it all set up on the fire wall and the brake pedal is way to low because pushrod is too short and non adjustable, it measures .501 so I was thinking about cutting it in half and running a die down both sides and using a threaded rod coupling nut with 2 jam nuts on either side. to make it adjustable.. is that rod hardened? my tap and die chart says 1/2 - 20 finished piece should be no thicker than .4987 so its only .0023 thicker than the finished piece.. if its hardened won't this be a little rough on the die? if it were mild steel I wouldn't care, but it looks hardened. and if I botch this I have to get another booster..

 

You should be able to tell by using a "portable hardness tester"; just a nice & sharp common file, to see if it's hardened.

If it slides right over the material without removing anything, it's hardened....if it actually cuts into it, it's soft.

 

well duh.. lol gonna have to try that.. so the .002 over whats everyone's thoughts on that?

 

I've cut several M/C push rods in half and threaded both cut ends. I then took a length of hex stock, drilled & tapped both ends , cut it to the appropriate length and screwed the push rod ends into the hex stock to get the length needed. The hex stock afforded a good place to use an open-end wrench on for adjustment. I've never run into a hardened push rod.

The .002" isn't going to make that big a difference.

 

If it is hardened, adjustable rods are readily available. But I have cut and threaded them without any problem. I think hardening them would make them too brittle for thier intended purpose.

 

Why go to all that work when you can buy a piece of rod and cut it to the right length? I have also made one out of a longer bolt with the head cut off.

 

On my '32 under-floor MC I used a long stainless hex-head bolt (3/8" I think) with the head cut off. I attached a heim joint with jam nut to the threaded end and rounded the other end to go in the MC.

 

FYI Speedway makes a clevis thats threaded as well, I took my non-adj rod, threaded it and used that clevis and works perfect

 

Almost any marine supply should have one.

 

You should be fine with the .501 diameter. I doubt the piece is hardened, probably 1018 mild steel. Use the coupler sleeve or nut as a thread gage. Most dies are split, so you can adjust it to take more or less of a bite.

Bob