Brake question (hypothetical)

Henry/Kokomo

Henry/Kokomo

Well-known member
I'm in the process of building an AV8 and encountered an interference issue between rear wheel cylinder brake lines and rear spring perches. My neighbor - a Corvette guy - suggested rotating the backing plates to alleviate the clearance issue. Can anybody see why this wouldn't work? Is there a reasonable limit to the amount of rotation (90* might be easy)? Looking for opinions or past experiences. Thanks in advance.
 
Henry what rear end,backing plate and perches are you using?
I have Ford rear brakes on 39 axle with cut down Model A perches.
My backing plates are about 5* to rear. With a tight bend that worked.

John
 

Attachments

  • image.jpg
    image.jpg
    76.9 KB · Views: 128
Walt ,Yes it has a flex brake hose from the junction to the frame. It is braided stainless and not period correct,but I couldn't find a rubber hose long enough.

John
 
Last edited:
Thanks for the input, guys. Mrtexas: Notching the spring perch may work. It seems that would be the least work. John in Illinois: Using a '39 rear axle and brakes with a '46 gear set. The spring perches are manufactured by New England Speed & Custom. These bolt to the upper two holes in the axle with Grade 8 bolts. There's plenty of clearance for everything except the brake line, which is tight. One thing I haven't tried was attaching the brake line to the cylinder prior to bolting it to the backing plate . Thanks again for all the input.
 
Henry,I bent my lines right next to the flare nut using Eastwood bending pliers. I clamped the pliers in a vice and used vise grips and a piece of aluminum
To form the bend around the Eastwood tool.

I used Cunifer tubing which bends easy,But I have used the same method with steel lines at the spring perch.
John
 

Attachments

  • image.jpg
    image.jpg
    55.7 KB · Views: 75
Last edited:
John you did very well if you were using those Eastwood pliers.. All they ever did for me was crimp the line ..doh! Hateful things...
 
i find clocking the backing plates the easiest way plus if you use the stock model a rear perch on a later year rear and want to use the ball for the lever action shocks that is the way to go.
weld up the 4 bolt holes in the backing plate and transfer new hole in the desired location using a spindle and transfer punch.
 
The old trick was to put the cylinders on the bottom. You switch the plates side to side and rotate 180*. That puts the emergency cable going forward but the cylinders LEVEL and on the bottom. You have to turn the cylinders over so the big ends are to the back and the bleaders are up. The shoes are swiched as well with the big to the rear.
This also solves notching the backing plates for clearance.
 
Last edited:
On 39-48 brakes the big part on the cylinder should face the front. The larger brake shoe lining also goes to the front. In a stock installation.
Bendix style brakes (Lincoln and 49 up) brakes have the short lining to the front.
Just for comparison.
Martin.
 
It has been many years ago when I put Lockheed(Ford) brakes on a Model A and indexed the cylinders to the rear. No problems but I wasn't concerned with having a hand brake.
 
Talkwrench, the pliers do make bad crimp marks on the tubing. They are not much good. I milled a groove in some aluminum and formed the tube around the pliers with no crimp mark.
I indexed the backing plates on my Model A Tudor and that works well too.

John
 
When I do it I clock them back about one bolt hole diameter so approximately 1/2". I have not had any issues hooking the parking brake cable up. You can always bend the parking brake cable tube going into the backing plate alittle .
 
You must log in or register to reply here.
Back
Top