Vintage Mustang Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
4,926 Posts
Discussion Starter #1
Hi all, it's Saturday night and the best thing I could think to do is to cruise the forum! About 2 months ago I started a "weekend" job of upgrading my 4 wheel manual drum brakes on the 65. I purchased a complete system from Praise Dyno brakes out of Texas. Also purchased a 67 dual master cylinder, stainless lines and braided steel flex hoses from Inline tube, new front hubs and bearings from Mustang Plus and new wheel studs for the hubs.

I put the whole thing together, after many difficulties with suppliers selling the wrong parts. The first time I tried to drive the car, a horrible grinding metal on metal came from the front wheels. Checked and it was not the bearings. hmmmm. It appeared that the drums were rubbing against the backing plate. I figured the new hubs were not as thick as the old by about a 16th or so, hence the rubbing. I came to this conclusion after putting washers on the wheel studs, between the drum and hub, and the noise went away. Also, I could see where the new black paint on the backing plate was wearing away.
I took the drums to a machine shop, which charged me $250!!! to machine down the inner ring of the outside lip. The first time they turned them down, they did not go down the 16th of an inch I requested. Had to take them back.


Yesterday I installed the newly machined drums and afterwards, the wheels would not turn. The wheels would turn with the drum on, but when the tire was put on and tighted down, the wheel would not turn. I figure that the outside edge of the brake shoes is making contact with the inner face of the drum. I measured the drum depth and shoe width, and it appears the drum is too shallow. I also compared with my old drum and it appears the new drum has less depth.

Since the cable clutch linkage broke (again) on my 70 (forget D&B Engineering- lousy product and too much money), I had to get this car on the road today so on went the washers between the hub and drum and the wheels rotate fine.

The problem is that the brakes barely, and I mean barely, stop the car. When the automatic choke is on and I back the car out of the driveway, I have to exert all of my leg power to stop the car. The pedal is about 1/4 inch off the floor when I do this. The pedal doesn't pump up, so I know there is not air in the lines. It seems like there is plenty of resistance, like there is shoe/drum contact, but it just doesn't stop well. Also, when I first step on the brake, it seems like the car loses rolling resistence, actually rolls better, , like the shoes are dragging when I drive, but when I step on the brake, they move and stop dragging for a moment, then they make contact with the drum. I think the back brakes are adjusted ok, cause I only have to pull out the parking brake handle about 5 or 6 notches to fully engage the parking brake.

What do you think I should do about the mismatched drum/shoes? Also, this setup with Praise Dyno Brake is supposed to be the best you can get, but my braking performace is actually degraded from what it was before I changed the parts. Did putting on a 67 m/c and using the 67 m/c rod have any cause for my pedal being on the floor for stopping? Why do you suppose that the brakes are not stopping the car, even though apparently engaged?

Any suggestions? I dislike putting major money into the car and then having nothing work right. I could have spent half the money at Mustang Plus and gotten a new system. This "upgrade" is a "downgrade". I've read good things about Praise Dyno Brake in the magazines and here, but right about now I am ready to flame them.

I appreciate any comments I receive here. Pretty much at my wits end on this. Thanks.
 
G

·
Guest
Joined
·
0 Posts
first make sure the brake shoes are not reversed. when that happens you dont get the proper braking action. second make sure they sent you the right shoes. third, why didnt you swap to front disk brakes?
 

·
Registered
Joined
·
4,926 Posts
Discussion Starter #3
The front and rear drums are of different size. The front drumss are thicker and take the wider shoes. The rear drums are skinnier and take the skinny shoes. If you swap the shoes, the rear drums won't fit over the shoes. The shoes were in a ziploc bag labelled front and another bag labeled rear, so I think I have them right. If I don't, hey, I am open to correction. As far as sending me the right shoes, don't know. I will check them against the old shoes. As for the swap to disc brakes, I read that the performance of this drum/shoe combination is equivalent to disc brakes and I wanted to keep the car as close as possible to original. Your points are well taken, however, and I appreciate what you have to say. Do you think I have the shoes swapped?
 

·
Registered
Joined
·
708 Posts
With swapped, I don't think he meant front drums/rear drums shoes swapped, but swapped per wheel. Like the left shoe on the right side of the drum and vise versa. I'm not 100% sure. It wouldn't be the first time though....
 

·
Registered
Joined
·
4,926 Posts
Discussion Starter #5
Oh, the light dawns. I see your point. Primary swapped with secondary shoe. I was following the shop manual picture, but maybe did not interpret it correctly. I put the primary shoe, which has the longer lining, towards the front of the car and the short shoe towards the back of the car. Is this correct?

Thanks for your input.
 

·
Registered
Joined
·
4,926 Posts
Discussion Starter #7
oh my gosh, I might have them reversed! I'll check later and see. So the primary shoe is in the back! Great to know. Now if I can figure out why my instrument panel lights go out when I step on the brakes and why I lack turn indicators and horn . . .
 
1 - 7 of 7 Posts
Top