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farmerdick 07-10-2020 12:19 PM

40 Ford Brakes
 

How reliable are the hydraulic 40 ford brakes when set up properly at their best. I put new drums, wheel cylinders a shoes on my rebuild and everything else was used and reconditioned. Also new master cylinder.

19Fordy 07-10-2020 12:23 PM

Re: 40 Ford Brakes
 

RELIABLE meaning: consistently good in quality or performance; able to be trusted.

I have found my 40 brakes to be a very reliable Lockheed style brake system.
I think that the general test is that if you can lock up the wheels and skid,you are good to go. They STOP as they were designed to with Lockheed technology of the day.

EFFICIENCY is defined as: (especially of a system or machine) achieving maximum productivity with minimum wasted effort or expense.

40 Ford brakes are not as efficient as the later Bendix system. I believe this indicates that if you had one 40 ford with Lockheed brakes and another 40 Ford with Bendix style brakes driving down the road at 30 MPH and you simultaneously apply both brake systems,the Benidix system would provide a shorter stopping distance as the Bendix system pulls the shoes tighter against the drum and requires less pedal pressure. Hence, it's more efficient.

That's why you always want to think ahead,don't tailgate and leave plenty of stopping distance with 40 brakes.

Here's an excellent discussion about your question.
https://www.fordbarn.com/forum/showt...5506&showall=1

V8COOPMAN 07-10-2020 01:35 PM

Re: 40 Ford Brakes
 

Quote:

Originally Posted by 19Fordy (Post 1907840)

I think that the general test is that if you can lock up the wheels and skid,you are good to go.

I believe this indicates that if you had one 40 ford with Lockheed brakes and another 40 Ford with Bendix style brakes driving down the road at 30 MPH and you simultaneously apply both brake systems,the Benidix system would provide a shorter stopping distance.


I know I've played with your words above, but there are a lot of variables to be considered....most-importantly, probably tire size. BUT.....tires being the same on both cars, if you can 'lock 'em up', they both should stop side by side! The Lockheed-equipped guy just has to grunt harder on the pedal. :) DD

hotcoupe 07-10-2020 01:55 PM

Re: 40 Ford Brakes
 

I drive a '37 1/2 ton, and when i was working on the truck i installed '40 brakes. All new or re-built components, arced the shoes, dot 5,etc.,etc never was confident in an emergency situation, installed re-pop Lincoln brakes on the front, the difference is night and day.
Tom

russcc 07-10-2020 02:07 PM

Re: 40 Ford Brakes
 

Properly setup '40 Lockheeds will put you through the windshield. Stopping quicker has more to do with tire contact patch than brake systems. Would I convert my '40 front brakes to Bendix, I likely will someday as I have the stuff.

32phil 07-10-2020 02:14 PM

Re: 40 Ford Brakes
 

Amen On the Bendix style over the Lockheed.
The difference is in the Bendix self energizing feature.
Lockheed with fixed shoes on the bottom do not have this.
The good news is the Lockheeds work well when used on the rear along with Bendix style on the front.
Original 41 Lincoln backing plates are pricey, Repro sets are around $450 to $500
F2 units are the most reasonable around $300 loaded

19Fordy 07-10-2020 03:08 PM

Re: 40 Ford Brakes
 

OK, Thanks for pointing out the failure of my brake question response.

I learned a few new tid bits.

V8COOPMAN 07-10-2020 04:34 PM

Re: 40 Ford Brakes
 

Quote:

Originally Posted by 19Fordy (Post 1907892)
OK, Thanks for pointing out the failure of my brake question response.

I learned a few new tid bits.


Jim....You didn't fail anything! Maybe I'm just too critical! YOU know as well as anyone that OVERALL, and for just about ANY reason you can think of, the BENDIX brakes cannot be beat in any category that I can imagine when compared with the stock Lockheed-type brakes. I was merely trying to point-out that with like tires, and with the brakes locked-up, one won't stop any shorter than the other. NOW, as tire contact patch increases in area, the Lockheed brakes will become more and more marginal, until a point where there is so much tire in contact with the road that the brakes are not able to overcome the road friction with brake shoe friction. At that point, the Bendix brakes are just beginning to come into their own element. The reason that Lockheeds on the rear work well with Bendix brakes on the front is because under hard braking, weight transfers forward making the rear of the vehicle lighter, allowing the rear wheels/tires to lock-up even more-easily, as the work load requirements increase on the front brakes because of the increased weight, and the increased friction imposed on front tires/road surface. DD

philipswanson 07-10-2020 05:54 PM

Re: 40 Ford Brakes
 

My juice brake linings on the rear of my 40 must be somewhat oversize because instructions given by the manual and other sources will not work. The way I adjust them is to turn the 1/4" adjusters for minimum drag, then turn upper 11/16 ones for as little drag as possible. Running Bendix brakes up front. One day I will do the rears too. This combination seems to work well but the fronts do 70% of the braking. I sure like the self actualizing Bendix design better.

farmerdick 07-10-2020 06:13 PM

Re: 40 Ford Brakes
 

Thank you so much for the info. I am going to fine tune the rear brakes as best I can, I had the new (repro)(china?) drums turned down today(30thousands) and they were out of round. Ok now!!! I am going to bench bleed the master cylinder next.

1931 flamingo 07-11-2020 07:42 AM

Re: 40 Ford Brakes
 

Where did you get the drums that much out of round from??
Paul in CT

philipswanson 07-11-2020 10:29 AM

Re: 40 Ford Brakes
 

Quote:

Originally Posted by farmerdick (Post 1907944)
Thank you so much for the info. I am going to fine tune the rear brakes as best I can, I had the new (repro)(china?) drums turned down today(30thousands) and they were out of round. Ok now!!! I am going to bench bleed the master cylinder next.

It could be that the brake lathe that was used had shot bearings too.

John R 07-11-2020 11:04 AM

Re: 40 Ford Brakes
 

Quote:

Originally Posted by V8COOPMAN (Post 1907915)
Jim..........The reason that Lockheeds on the rear work well with Bendix brakes on the front is because under hard braking, weight transfers forward making the rear of the vehicle lighter, allowing the rear wheels/tires to lock-up even more-easily, as the work load requirements increase on the front brakes because of the increased weight, and the increased friction imposed on front tires/road surface. DD


For the reasons stated, it is best to leave the Lockheed fixed-anchor brakes on the rear. In an emergency stop and/or on wet roads, the rear Bendix brakes will lock up more readily. When the locked-up rear end comes around, you have an exciting situation, to say the least. This is a well-known problem with cars that use Bendix front and rear.

blucar 07-11-2020 11:30 AM

Re: 40 Ford Brakes
 

A little clarification info on hydraulic brakes.
The words Lockheed and Bendix have been bantered around in all of the postings to this topic.
The original question posed was relative to '40 Ford brakes which are typical on '39-41 Ford/Merc cars/trucks.. This is generally referred to as "Lockeed" type brakes.
The short comings of the '39-41 brakes are that they are very hard to keep in proper adjustment due to the lower anchor points which require adjustment, ideally this has to be done with the drums off of the vehicle.
The Bendix style '42-48, have floating lower attachments which do not require adjustment.
I converted the brakes on my '36 to '41 hydraulics in 1952.. I lived in Idaho at the time, the brakes worked good for many years. I moved to Los Angeles in '56, drove the '36 in daily freeway/hiway traffic, I found the '41 brakes to be very marginal. In 1959 I got a company vehicle and did not have to drive the '36 in traffic for the next 14 years, however, even in pleasure driving the '41 brakes were marginal.
I have been in the process of upgrading the entire mechanical components on my '36 for the last few years, one up-grade requires a conversion of the brakes to '42-48 brakes with my '39 drums, which have been on the car since '61/62.

19Fordy 07-11-2020 11:54 AM

Re: 40 Ford Brakes
 

7 Attachment(s)
My experience has been that the 40 Ford brakes can be adequately adjusted with the drums on the vehicle if the steps outlined for properly adjusting the brakes are followed AND the shoes are arced to fit the drums.

tubman 07-11-2020 12:14 PM

Re: 40 Ford Brakes
 

I'm just a "Shoebox Guy" so my knowledge about this is limited. I've always wondered why the early ('39-'41) brakes weren't considered superior than the later ones ('42-'48). I would think that the adjustable lower anchors would make getting better shoe contact possible, even though it complicates the adjusting procedure.

When I built my first "T" bucket in the '60's I used them for just this reason. (There were lots of parts available back then.)

rustythumb 07-11-2020 12:24 PM

Re: 40 Ford Brakes
 

'46-'48 ford brakes are still lockheeds. also, isn't the tire contact patch the same size in sq. in. with any type of tire? [ on same car with same pressure? ] please correct me if i'm wrong!

1931 flamingo 07-11-2020 01:28 PM

Re: 40 Ford Brakes
 

If I run a 5.90-15 on the front and an 8.20-15 on the rear, the rear has a lot more contac5t area. JMO
Paul in CT

farmerdick 07-11-2020 01:34 PM

Re: 40 Ford Brakes
 

First note about the lathe: This is a reputable shop and experienced machinist. I got the drums from Mac`s. I`ve adjusted the shoes so that they are all grabbing the drums properly. I re-bled the master cylinder on the bench and re-did all the lines and have no air in them. What I do have is a pedal that travels 3 to 4 inches before I have any resistance. I`ve adjusted the push rod as far as it will go. Am i missing anything here?

farmerdick 07-11-2020 01:40 PM

Re: 40 Ford Brakes
 

P.S. I should only have a 1/2" free play according to the manual that 19 Fordy showed above which i have a copy. It seems to me that i should have a much harder pedal with less free play.


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