’35 Mechanical Brake Rod Shape Question

[VeryTangled]

’35 Mechanical Brake Rod Shape Question

Hi Everyone, While crawling under a '35 car, I observed the brake rod in the attached photos. (At least one other brake rod on this car was similar.)

My question is about the straightness of the rod. I see a 'Z' shaped profile, instead of a straight line.

My experience with these rods on our '36 is that you need to have as close to zero bends in them as possible. When they are bent, and you're trying to transmit force from pedal to shoes, the rod will flex at the bend, and reduce the force, correct?

In the spirit of having a lively but civil discussion... What comments do the 'Barn'ers have about what I've seen?

 

[1935coupe]

Re: ’35 Mechanical Brake Rod Shape Question

mine are the same shape to the rear and the rear are always the one to want to lock up during hard braking

 

[glennsanders]

Re: ’35 Mechanical Brake Rod Shape Question

That Fords first attempt at anti- lock brakes lol..

 

[VeryTangled]

Re: ’35 Mechanical Brake Rod Shape Question

Hi Again Everyone, I did find a photo in the Don Rogers book, he also helpfully had the part number, the rear one is 48-2499 and front 48-2495.

 

[DavidG]

Re: ’35 Mechanical Brake Rod Shape Question

The correct rods were originally straight as an arrow from front to back with an offset (at an angle) eyelet at the clevis pin end. As you will note from Don's photo, the brake rod support is noticeably different than that in your photo, which are either '32s or '33-'34s depending on their length.

It is almost as though your rods were bent to accommodate the brake rod supports plus they are likely too long and the bend had the effect of shortening them. Unfortunately the bend also diminishes the amount of force at the brake backing plate as they would stretch a little each time you used your brakes.

 

[Frank Miller]

Re: ’35 Mechanical Brake Rod Shape Question

I don't think it diminishes force as much as it increases brake pedal travel. The idea behind mechanical brakes is to have as little play as possible in the system. The pedal force will straighten the rods a bit before applying full pressure to the brake mechanisms.

 

[MGG]

Re: ’35 Mechanical Brake Rod Shape Question

When I began restoration on my 34 BB truck I noticed that each of the two front brake rods had a slight bend in them. I thought that can't be correct so I took them off and straightened them. On the first drive the front tires hit the rods when I made sharp turns, both left and right so I put the bends back in the rods so the tires would clear in sharp turns. I thought I would experience diminished braking ability but I could not detect any difference with the bends in the rods.

 

[JM 35 Sedan]

Re: ’35 Mechanical Brake Rod Shape Question

This is about the third instance I have seen, or heard of in the last six months, of bends like this in mechanical brake rods on 35-36 passenger cars. I also had some rods bent similar to this in my collection of used '35-'36 brake rods that I have gathered over the years of owning early Fords. It's sometimes difficult to convince the owners of the cars with mechanical brakes, that their brake rods should NOT have this type Z bends, or any type of bends. If they are there, some folks think this is the way they were made, and are reluctant to straighten them or change to other rods that are not bent.
The straighter you can get these rods, the straighter they will pull, and the better the braking will be.

 

[Bored&Stroked]

Re: ’35 Mechanical Brake Rod Shape Question

My guess - either the wrong rods, or somebody tried to "tighten up the brakes" by shortening the rods (by putting a z-bend in them). Also, my guess is that the "reason" it was done, is most likely related to worn components than anything else.

When I first got my 32 cabriolet (mechanical brakes) - it had been sitting for 55 years - which in a way was good (not been messed with). I went through the brakes and rebuilt everything - and it took a bit of time to get it right. Two of the rods were very worn on the threaded ends back by the trans, so I reworked them - by buying 5/16 steel rod and grafting/welding new ends onto them (with new threads). I straightened every rod, put new brake shoes in and went through all the mechanisms. In the end, these brakes are perfectly fine and work well - for my usual back-road cruising. I get up to about 65 mph on some of the roads. The most important thing is to get them rebuilt correctly and to keep them adjusted properly - other than those two things, they're quite usable and stop quite well (no pulling to either side).

Now - for high speed freeway cruising - especially in traffic . . . probably not the best. I will be putting a complete set of hydraulic brakes on the car (Lincoln Bendix style) - for better braking. The good news is that I'm keeping ALL the original stuff - such that it can be put back in the car if I or somebody else wants to do this. I figure I'm just the temporary caretaker of the car . . . I want future generations to have what they need to put it back to 100% stock.

 

[JM 35 Sedan]

Re: ’35 Mechanical Brake Rod Shape Question

Good thinking B&S. I got the mechanicals working well on my 35 fordor to the point I don't think 39 to 48 hydraulics could stop me any better, BUT... the mechanicals will always require more tuning to maintain equivalent braking as compared to hydraulics, JMO. If/when I ever convert to hydraulics, I would also definitely go straight to the new Lincoln Bendex brakes.