VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 1940 Coupe brakes - disc upgrade?

I'm looking at Chevs of the 40s and they have a front disc brake upgrade kit for my 1940 Chevy Business Master. I'm keeping the original engine - which runs fine. (and thanks to those of you who gave me advice on the transmission!). First, does anyone have experience with their disc brake upgrade kits? Second, what about the Mustang II front ends? Will those fit with the original engine?

As I mentioned in my other post, this is my first build so apologies for any obvious/newby questions.

Blue40,

You keep modifying your car and pretty sone it will be a modern car. Its a slippery slope and you may end up with a far cry from the old mechanics of that sweet 1940.

There is nothing nostalgic about running around in a car that has lost all connection to the old car the title states you have..

So. I recommend you reconsider modifying the car in any way. Adventure is realized only by driving it on a long enough trip that you may expect to test its endurance. Therein is the thrill of adventure.

When I bought my 1941 cabriolet in Hudson, Illinois back in the seventies. I drove it home. Then when I retired from the army, I drove it to Wyoming and back, then to Erie. PA and back. On those three trips the following happened:

a. Had a short in the taillight wiring. After several fuses and tracing warm wires I found the wires were shorting to a oil can in stored in the corner in the trunk. Almost no brakes owing to all but two pistons in the wheel cylinders being stuck. This was on the way back from Hudson, IL

b. Lost a fan blade in middle of Wyoming just east of Rawlings. Caused water pump to begin leaking. Found one in Rawlings.. Put it on and continued on to Thane, WY.

c. Blew a wheel (rim) went to a junkyard and got another one and a spare tire and tube. This was in Maryland on the way to Erie. Pa.

d. Had transmission trouble. Had to park the car, rent a van to haul my parts and later buy some gears to fix it. Took the transmission out twice with help from a friend I found in western PA.

e. Coming back from Erie, noticed that the amp gage showed no charge, Lights were getting dim. About 1:AM. Had a brush in generator stop working - worn out. Parked on an incline so I could roll start it if necessary. Had a spare in my tool box. Put it on in a closed service station near Washington, DC.

All this was adventure, i.e, it wasn't fun while it was happening but later I wouldn't take anything for the experience.

I know that for some modification and modernization are the thing but for me I won't ever go there. I figure. what's the point? Probably none of those breakdowns described above would have happened if I had been driving a street-rod, modified or modernized vehicle. Just boring travel. Nothing more.

You may want to reconsider those disc brakes. Nothing like those old Hucks and the original drive train. Nothing.

Best,

Charlie

Thanks Charlie - it's a slippery slope indeed. And I agree, the fun of driving something that's not modern is the entire reason we bought the car.

Remember that brakes are a system. You need to consider the impact on the whole system due to changing any one component. For example, the disc brake conversion will require that you install a dual chamber master cylinder and an adjustable proportioning valve. And that also requires different steel brake lines going to the front and rear brakes. How will the system perform if you do not install a boosted dual master cylinder?

While I am not quite the purist that Charlie is I do encourage staying closer to original if at all practical.

Are you unhappy with the braking performance today? If you can lock the front wheels and slide the tires today then the brakes are giving you everything you need.

Because you are keeping the same drive train you are not going to be traveling any faster than the car was designed to operate.

With respect to the Mustang II style front end conversion, I do not have any direct experience with that. I will offer the same guidance because steering and suspension are systems. Can you install that front end and keep the current steering gear box? How will you handle the fact that the front hubs are 5 bolt and the rears are 6 bolt?

Some people call it a slippery slope. I consider it more is the edge of a cliff.

Good morning Blue 40

Those of us who have mechanical, fabrication, machining, welding, etc skills can really enjoy applying them to our antique vehicles. Projects that improve mechanical function are irrelevant to owners of trailer queens. But vehicles that are actually driven are safer and more pleasant to drive with some upgrades. Even severe modifications can be reversed. For example when I first got my '36 Chevy PU in 1965 I was a 20 year old college kid and I made a rat rod out of it with a small block Chevy V8 engine, B & M "Hydrostick" transmission and '59 Chevy PU rear axle. It was a totally reliable daily driver in that configuration for about 5 years and 50,000 miles. But you'd never know that looking at it today because it's now restored and looks original. So whatever you do, you can undo.

Charlie lists his mechanical failures and states that he found that they kept his outings from being "Just boring travel". I prefer reliable transportation, but to each his/her own.

Rusty points out that your contemplated brake modification will require a tandem master cylinder. I think he is right, but that is a valuable safety upgrade. I put a tandem MC in my '36 to improve safety. It tucks into the original MC location and no modification of any kind was required except fabricating a mounting bracket for the tandem MC, a longer MC push rod and 2 brake lines with 10 psi residual pressure valves (the original MC has a 15 psi rpv) going from the tandem MC to a "T" fitting area on the right frame rail that formerly split the front and rear brake lines. Those modifications are invisible unless one crawls under the PU and they can be easily undone in the future. Obviously I saved all the original parts.

Some other "stealth" modifications on my '36 include 3.55 rear gears: https://vccachat.org/ubbthreads.php/topics/334876/1936-chevy-3-55-rear-gear-conversion.html

Modern tie rod ends on the tie rod and home made drag link to vastly reduce steering slop.

Steering box modified with an oil seal in the sector housing to allow use of gear lube as a lubricant reducing steering effort.

1946 PU window regulators.

1935-40 Ford fuel pump diaphragm to avoid having to buy a whole "kit" just to get the diaphragm I needed.

Seat belts.

A 1939-40 Chevy Carter W1 carburetor with 1937 Chevy jetting that significantly improved starting, idling, power and fuel economy over the more primitive 1936 carburetor that I saved.

A paper air filter element in place of the original oiled screen. I save the screen.

And probably other modifications I can't remember after all these decades.

So I would say "Have fun and go for it", and if you do the modifications and change your mind later you can go back to the original condition. That might be challenging after doing a Mustang II conversion but nothing is impossible. The 5-lug/6=lug issue is not an insurmountable problem and has a variety of solutions.

Have fun!

Ray W

I appreciate and agree with both Ray's and Charlie's comments.

Ray has a high degree of technical skills and capability so he can do things that are beyond the scope for many of us.

If you look at my '37 it will not take a knowledgeable person very long to realize that it is not near as "original" as your first impression. And there are still a few more changes I plan to make this year to better suit the way I use the car. But they will not be obvious at first glance.

It is your vehicle and you should do what makes it the most enjoyably for you. My primary point is that you always need to consider the full implications of any change you make. And then do it correctly. Don't get cheap half way through or you will be frustrated and disappointed in the results.

"I appreciate and agree with both Ray's and Charlie's comments.

Ray has a high degree of technical skills and capability so he can do things that are beyond the scope for many of us."

Rusty,

Thank you for the compliment. I really appreciate it.

I felt like I had no choice but to learn those skills. In 1969 I finally finished college, got my first job as a geologist and finally had some money. So I started planning a restoration of my then "Rat Rod" '36 PU by taking it around to some body shops to find out about repairing all the dents and rusted out areas. What I heard shocked me. The body shops said they would use "Bondo" in making the repairs. To me that is plastering, not body repair. How could a vehicle with the damaged body areas simply filled in be considered "Restored"?

So I found an evening adult education class in auto body repair, taught by a body man with actual metal straightening skills. Three semesters later I'd reworked all the body panels except the tailgate and that I made new from a piece of sheet metal and some steel round tubing for the top.

At that time I was a VCCA member and in G & D I read horror stories about ill fitting wood kits so next was a couple of semesters in evening adult education wood shop.

All the mechanical stuff I learned as a kid growing up in Southern California, the epicenter of the car culture. For example, right across the street from my elementary school was a race shop where I actually saw Indy cars being fabricated, beginning with laying out in chalk on the concrete floor the chassis configuration.

To anyone who's wondering if it's hard to learn body repair and painting, wood fabrication, welding, machining and any other skills that go into restoration/street rod building/etc., the answer is "No". It's actually pretty easy and a lot of fun to learn those skills. The time spent learning them is much more enjoyable than passively watching TV, pro sports, erotic dancers at the bar, etc, etc. The added benefits are not being dependent on overpriced "professionals" with marginal skills and at the end of the job being able to look at the finished product and being able to say to one's self "I did that".

I think having done everything on my '36 PU myself except the engine cylinder boring and bearing pouring, chrome plating and glass cutting is why in owning this same '36 since 1965 I've never grown tired of it. It's still fun to drive at least a couple of times a month and to look at and say to myself "What's next to make it safer and more pleasant to drive?" Maybe turn signals stealthfully hidden in the original headlights and taillights? They could be controlled by a hidden and simple 3-position toggle switch.

Ray W