Davidmij - Disc Brake Conversion & Rim Problems

[RustyNCa]

OK, I have another problem. (my on going brake saga) I found 3 wheels for my front and a spare at a Santa Fe junk yard. I then found a couple of roller tires at a local gas station and busted them by hand. One of the tires had a hole in the wall so I had to get another one. I forgot how much work it is do tires by hand! Anyway, I got her fired up and rolling but the brakes are not getting any power. It's like driving with the engine off. I remembered I had a vacuum line open at the wiper motor so I plugged it with a bolt. I basically have just the vacuum line off the intake manifold going to my power brake module. The rest are removed. I'm guessing that's not enough? I have no idea how vacuum lines power things. Can anyone offer advice on this?
Thx, Dave J

One line should be enough if you plumbed it correctly. Do you still have a check valve in your vacuum line? You might also check and make sure it still works if it is there.

Also did you run the line straight to the booster or does it go to the canister in the drivers side fender first?

I haven't read about your brake saga, is the booster new?

[davidmij]

That is a SHARP looking car Rusty. Those wheels are perfect. The front end and hood on that vehicle are pure art.

[davidmij]

Everything is new.
No check valve, it runs straight from the manifold. I removed the canister too. Turns out I have the the larger reservoir going to the rear brakes. I'm guessing that makes all the difference. I also plunged the line going to the windsheild wiper motor - I have plenty of vacuum, and with the engine off if I hit the brake pedal i can hear the air leaving the power assist unit like it should. I'll switch the lines tonight and check it out.
thx!

[RustyNCa]

Everything is new.
No check valve, it runs straight from the manifold. I removed the canister too. Turns out I have the the larger reservoir going to the rear brakes. I'm guessing that makes all the difference. I also plunged the line going to the windsheild wiper motor - I have plenty of vacuum, and with the engine off if I hit the brake pedal i can hear the air leaving the power assist unit like it should. I'll switch the lines tonight and check it out.
thx!

Pretty sure you need that check valve to maintain the vacuum in the booster. It is a one way check valve that keeps the vacuum from bleeding off, I am pretty sure the system won't work right without it. I know I had one die in my olds, and the brakes didn't work correctly without it, and that system is very similar to the TBrid.

The canister is nice to have, it's job is to maintain a small reserve of vacuum to power systems needing the vacuum. It was nice of Ford to put them in their cars, I had to add one to my olds, I would run out of brakes in traffic prior to adding the canister to it.

The system will work without the canister, but in other words, I would keep the canister in the car if I was you, it is a great help to the car.

Cheers
RustyNCA

[davidmij]

Hm, I had thought that I only needed the shutoff valve if I had the canister - being that it came off the "T" fitting. What you're saying makes more sense though. The valve would keep suction in the canister for when the brake pedal is depressed - that would give it enough to boost the power and stop a non running car. I guess I'll find out tonight if it's needed or not. I have to reverse the brake lines anyway to put the small reservoir to the back brakes and large to the front. I'll try it like that and see if it works. If it doesn't I'll put the valve back in line and plug the canister in too. Good thing I save all my old parts. This car is a Road Rat type project so anything I can remove that is extra weight will eventually be pulled. The canister thing is nice, but it seems to me that all new cars don't have any kind of brake back up so I thought it really couldn't be that important. I'll definitely post my results to let you know. Thanks for the input Rusty!

- Dave J

[davidmij]

Well, neither way worked. I replumbed it so the large reservoir goes to the front disc, and the small one goes to the rear. That didn't change the brtake pedal at all. Then I added the one way valve so that it allows the air to be pulled into the engine (out of the booster) and nothing changed.
any other ideas gents?

[jopizz]

Did you try sucking on the hose that comes out of the booster to see if it holds vacuum. That's an easy test to make sure you have no leaks. You can try a vacuum pump also if you have one.

[davidmij]

Hadn't thought of that John, thx for the tip. Pretty sure it's holding air though because the first time I step on the brake pedal (after shutting off the engine) I hear the air leaving the booster.
By the way, does anyone know for sure if I need the 2 way valve that goes to the canister that is behind the fender? I was thinking that the valve is only to keep pressure in the canister. I tried with it, without it, with it reversed, while standing on one foot, and with my fingers crossed. I'm stumped.

[simplyconnected]

David, you now have two threads with the same brake discussions. Please keep your brake and tire threads separate so we can 'search' and find them in future.

I read that you correctly plumbed your front brake calipers to the larger master cylinder reservoir.

I also read that you have changed your vacuum lines around. Your new booster came with a check valve (that 90˚ ell) that your vacuum line pushes onto. You already know the vacuum inside the booster holds. Any more vacuum reservoirs will not help or hinder.

I asked you to do some tests, but I see no results for any of them. You show no pictures, so I only know what you describe in words (whether accurate or not). If you still want my help, I await your test results, instead of going off on tangents.

- Dave Dare

[davidmij]

Guess I did get a little ahead of myself there, sorry.
OK, 1) I don't understand what you mean by the "top pin".
However the booster does return to the at rest position. Maybe worth noting, there is a little slop in the pedal when it is in the at rest position. Once again, I can depress the brake pedal and release the air so I believe the pedal is in an OK position.
2) I watched as my son depressed the pedal and nothing seemed to be binding at all. The pedal never bottoms out to the floor board, it hits the point where the brakes move the disc pads, but it takes a lot of foot pressure to actually stop the car. If I am rolling at 25 MPH and slam on the brakes with both feet it won't lock up. It comes to a slow, gradual stop. The pedal has a normal range of motion.
3) I don't understand what you want me to check here. If you look at the picture the M/C mounts flush onto the booster. There is no gap.
Another thing maybe worth noting; I removed the K/H under dash booster all together.
I'm at work right now so I can't take and send pictures, but I promise I will by 7:00pm mountain time tonight. I'll try to call the guys at abs power brakes who sold me the unit. It's the same unit (if you look at my link below) that OID sells. He was out of them so he suggested I order from the Ebay site.
thx again everybody!
- Dave J Please wait
Image not available

[jopizz]

I apologize if this has been covered but can you tell me exactly what configuration you have. Did you install a booster on the firewall when you went to discs or do you still have the standard '59 configuration with the vacuum canister and under dash booster. One of the purposes for the check valve is to prevent gas or other fluids and gasses from getting into the booster from the engine so it is always used.

[davidmij]

No apology necessary, I kind of screwed up and posted in two places. Here's the other thread, http://squarebirds.org/vbulletin/sho...6265#post56265
If you look at my first entry it shows two links to my M/C and proportioning valve setup. I removed the K/H booster and went with the same setup that Simplyconnected used. The scarebird bracket using my original spindles. Then calipers and discs that fit onto the new bracket. Ran new lines all around. I kept the existing drums and wheel cylinders on the rear. If you have a minute read that other thread and post to there. It's only a few entries, but it should give you a better picture of what i have. Here's the only pictures I have of it so far, I'm going to post more tonight of the M/C and lines, etc. https://picasaweb.google.com/1014928...K6Gg9yhpdfGWg#

thx!

[RustyNCa]

I used this proportioning valve: http://cgi.ebay.com/ebaymotors/Ford-...Q5fAccessories
Can anyone offer advice on this?
Thx, Dave J

I ran a proportioning valve that looks alot like that one on our 58 tbird.

That said, first I think you need to solve the problem with your power assist, but you have to spend some time setting the valve up for your car, unless you are luckier than I and it works correct out the box. Once you get the power assist working you need to take the car out and adjust the proportion valve to put the bite where your car needs it.

I had to spend some time getting the valve set to bind down the front discs harder than it was out of the box. Before I did adjust things the brakes would slow the car, but didn't do the job in a panic stop. I think my valve was putting the brakes about 50/50 and you need more braking to the front.

Cheers
RustyNCA

[jopizz]

Are you still using the original vacuum canister? It really isn't meant to be used with the brake booster you have. The '59 vacuum canister has a check valve on the input and an output to the under dash booster. The '60 vacuum canister which is meant to be used with a booster has no check valve and only an input. There should be a check valve between the intake manifold and the new booster you have. If you use the old vacuum canister you have to block the output port that went to the under dash booster which you said you removed.

[davidmij]

I removed the back up canister from behind the fender and removed the valve that was in line from the intake manifold to the it, and the under dash assist. So i just ran the intake manifold line to the new power booster. I also tried putting the valve back in - neither way works. I removed everything else to do with the vacuum system. I have no little wheel that rubs against the fan belt and gives vacuum to the windsheild wipers. I unplugged the other line that comes from the manifold and feeds the wind shield wiper motor - I plugged that one. It gets a good amount of vacuum - if I disconnect the line from the power booster I can hear the suction and it causes the car to stall. Also, if I shut off the motor, then depress the brake pedal I can here the air rush out of the power booster.