what spindles

[V8COOPMAN]

Originally Posted by '28 RPU

Again, thank you to everybody for the help. Coopman, I have to conceed that there is a strong possibility that the disc brakes will set the wheels out forward. I do not have any space to give for that, the tires are just barely inside the fender bead as it is. When using the later spindles I know that anoter bolt on arm must be installed for the side steer drag link. Do you then cut the outer eye off on the spindle arm?

Don....You can, and it will certainly LOOK better. Leaving it in place won't hurt a thing, though.

This brings up a whole different part of the puzzle, although not a serious matter. When the geometry was engineered into that ARM (or EQUIVALENT) on both Model 'A' as well as '32-'34 Fords, it should be noted that the ANGLE where the drag link meets that steering arm was designed to be 90º when the front wheels point STRAIGHT ahead. If you look at the example BELOW, you will likely see the situation.





This is done because of the angle of the drag link. The location where the drag link is attached to the Pitman arm (when looking down from above) is noticeably farther INBOARD than where the front end of drag link attaches to the spindle STEERING ARM. Thus with the front end of the drag link angled OUTWARD, this STEERING ARM on spindle is angled forward to make that junction 90º at the CENTERED position. OTHERWISE, the car would steer a tighter turning circle to the LEFT, and a WIDER circle when turned to the RIGHT. It wouldn't be that noticeable in MOST driving situations, but the new add-on arm can be constructed to match the original Ford geometry. NOTE the two examples BELOW.

Coop








Your new roundback with bolt-on steering arm should look similar to pic BELOW.





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[jeepguy1948]

Sorry Coopman, same as last time the links themselves didn't make it thru. Thanks, Don

[rich b]

Originally Posted by '28 RPU

I have to conceed that there is a strong possibility that the disc brakes will set the wheels out forward.

Where did disc brakes enter the picture; your original #1 post mentioned '40 brakes?

With disc brakes you definitely need '37 up spindles as that is what the kits are made for.

The only common disc brake kit that doesn't set the wheels out are the ones using the F-150 rotor/GM midsize caliper.

I don't know of any kit that will work with wire wheels without an excessively thick spacer, again spacing the wheel out.

[V8COOPMAN]

Originally Posted by '28 RPU

Sorry Coopman, same as last time the links themselves didn't make it thru. Thanks, Don

WOW! That's OK....Click this link BELOW! Coop


https://www.fordbarn.com/forum/showp...4&postcount=21

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[V8COOPMAN]

Originally Posted by rich b

Where did disc brakes enter the picture; your original #1 post mentioned '40 brakes?

With disc brakes you definitely need '37 up spindles as that is what the kits are made for.

The only common disc brake kit that doesn't set the wheels out are the ones using the F-150 rotor/GM midsize caliper.

I don't know of any kit that will work with wire wheels without an excessively thick spacer, again spacing the wheel out.

He wanted the '40s NOW, and to have the option of converting to discs at a later date.

Coop

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[rich b]

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Originally Posted by V8COOPMAN

He wanted the '40s NOW, and to have the option of converting to discs at a later date.

Coop

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That's right, should have remembered that plan was raised in another thread he has going; but if mentioned in the first post, it would have changed the direction of this one.

[jeepguy1948]

So here's a question for you brainiacs, on stock '40 Lockheed brakes the front wheel cylinders are bigger than the rears. To me this means the rear brakes will start to engage before the fronts (I do understand that ultimately the front brakes will apply with more force than the rear) We don't want the rears to apply first do we? all this is assuming a dual circuit master with no proportioning valve. I eagerly await your response 'O Wise Ones. Signed, Grasshopper

[V8COOPMAN]

Originally Posted by '28 RPU

So here's a question for you brainiacs, on stock '40 Lockheed brakes the front wheel cylinders are bigger than the rears. To me this means the rear brakes will start to engage before the fronts (I do understand that ultimately the front brakes will apply with more force than the rear) We don't want the rears to apply first do we? all this is assuming a dual circuit master with no proportioning valve. I eagerly await your response 'O Wise Ones. Signed, Grasshopper

I've read that it is actually favorable to have the rears apply first, such as when the road surface is slick. I believe that I'd rather have the rears lock-up in that slippery situation than the fronts, for sure. It should keep the "steering" wheels/tires still able to steer. Wish I could remember where I read that info. Coop

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[cas3]

I think with the different size bores in the wheel cylinder, The rear shoe with the smaller bore will move first on each wheel, not the rear axle set. I also find it hard to believe anyone would notice the difference if it were the other way around.

[jeepguy1948]

well, my thoughts (or what you might say lead me to ask the question) Henry had engineers to figure this stuff out and if nothing else where to change then I would just agree that the way it was designed was best but when you go to a dual circuit I just wondered if that might change anything is all. My wife drives a mustang with 4 wheel discs and I know that the rears apply before the fronts to help limit nose dive (and possibly other reasons as well). the downside is that you can't do burnouts with it :-(

[rich b]

Just because they are different sizes doesn't mean there is a difference in the PSI applied to them; whichever piston moves first will stop with minimum force on the shoe until the other piston moves and meets resistance and then the pressure on each piston climbs equally and exerts force on the shoe in proportion to the piston area.

This plays thru out all eight pistons in the system with application PSI raise pretty much at the same time.

With a dual master some of this happens inside the master as the pressure build in the primary side reaches the point it moves the secondary piston; but again it happens pretty much at the same time.

When other valves like metering and proportion are added to the system is when things work differently.

No need for them in most drum brake systems unless parts selection is messed up.

Most common old time juice brake combos used; 4 Lockheeds or 2 Lockheeds rear and 2 Bendix front work together OK.

Another thing to note; 1/4" lines (like Henry did) should be used with Lockheed brakes. It's about fluid flow.