Brake rod straightness

[Brianpfreeman]

Rebuilding brake system to get the 30 coupe road worthy. Just rebuilt cross shaft and all brakes at the wheels. Reinstalling the rods soon and noted several have minor curves or minor bends. Are the rods suppose to be true straight?

[Canton_Model_A's]

From what I understand yes, they need to be true and straight. I just did the 4 on my 29 Fordor. They aren't that expensive, I got mine I believe from Synders.

Dave

[jack backer]

One of the differences between mechanical and hydraulic brakes is equal application pressure at all four wheels, hydraulics equalize on application with proper shoe adjustment, the mechanicals rely on a proper foundation, the mechanical linkage needs to be true, and proper shoe adjustment. Bent or curved rods will ‘absorb’ application pressure,giving poor equalization and function.

[Oldbluoval]

Use original rods where you can. In the past (10-15 years), repo rods would stretch …may be better now??

[WHN]

Replace the rods and any other connecting parts.

This is one place you don’t want to be cheap!

Enjoy.

[Ordsgt]

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My front were bent due to an accident. The right front was bent pretty good. I straightened them and they work great. Braking action comes from pulling on the rod. If the rod has a bend in it it can cause that brake to lose tension when applied. Some people say replace but I chose to keep my rods. Your choice

[J Franklin]

Use a vise, they can be made straight very easily.

[Brianpfreeman]

I applied some heat and straighten them all this afternoon. Used a long metal ruler as straight edge. Most off 1/4-1/2” Bend. Vehicle had some weird springs and home wire attaching them, probably the reason some got bent. Feel good about them now. Let them cool, sanded and painted.

[Joe K]

Originally Posted by jack backer

Bent or curved rods will ‘absorb’ application pressure,giving poor equalization and function.

This true - but the reverse may be true.

Going from the original "equalization" system (Ford went out of his way to have equal pressure on all four brake shoes on the early split cross shaft cars) to the more modern "solid center cross shaft" Ford "gave up" some of that equalization. Stretching of the rods/torsion of the cross shaft gives an "approximation" of the equalization theoretically possible.

I.e. there is a certain "spring" made into the system by its design. An equivalency for hydraulic systems would be "air bubbles."

AND Given that the Ford brakes are "manually" adjusted at each wheel anyway, and by their nature and human estimation "more or less" equally adjusted, the approximation was thought "good enough."

I guess I would say a "minor" bend is fine. In your adjusting you manually compensate for that anyway.

But straight is where you start. The first tree branch you run over will have other ideas.

Joe K

[Joe K]

And, as to original versus repop parts - the jury is favoring new parts, but not always.

A rather severe accident occurring as a result of the "center link" breaking at what appeared to be a weld at the "eye" caused the Service Brakes to fail - all four wheels.



This is Snyder's picture for that particular rod - but it doesn't match the pix in my mind's eye.

The issues seemed to be to be not properly made, the swelling for eye originally done by "upset" and the repop being an "applied weld."

Joe K

[figment]

I have had a front reproduction brake clevis snap completely in half when stopping . It sounded just like a rifle shot . It happened to be made from cast Iron!! It should have been made from forged iron . This might have been a older reproduction part because I haven't seen any more like this in quite awhile . You might check your spare parts collection for some of these clevis.

[Redbird]

Brian, are the weird springs the anti-rattle springs?

[Brianpfreeman]

No it’s a random spring and baling wire. Home made repair I’m sure of it. One of the pins was installed in the wrong opening on the Clevis end too.