Drum brake issues

[sqrlnts]

Recently my front left drum brake wheel cylinder started leaking. I have 4 wheel drum brakes on my 57 and the original rebuilt master cylinder. Luckily the brakes quit working near my house so no wrecks. Up to this point I had a very nice (for drum brakes) pedal.

I replaced the left cylinder and filled the very empty master cylinder back up.

Ever since this I have had a very poor brake pedal. Tonight I decided to bleed all 4 corners. I would pump the pedal several times and hold it in place with a board and started bleeding the LR wheel, then RR, then RF, then the LF. The pedal got somewhat better but would come and go when doing the fronts. At times the pedal would firm up and then I would lose it completely.

I have self adjusting rears but not front. I made sure the brakes were adjusted properly before bleeding.

I am wondering if I need to remove and bench bleed the master?
I have read that I can pinch the rubber lines to eliminate the wheel cylinders. Also wondering if I can get an inverted flare blank off to do the same to the rear since it has a braided AN line.... Any ideas??

Thanks in advance.

[OrrieG]

get some self bleeders for the wheel cylinders, you are getting air back into the system.after you install them pump the brakes alot making sure the pedal fully returns and the mc does not run dry. crack each bleeder in rr, lr rf,if order. eventually you will get all the air out.
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[sqrlnts]

Thanks Orrie will give it a go tonight.

[lazypineapple]

R u using a hose and bleed bottle?
If not, get a foot long piece of vacuum hose or like..
Slip hose over bleed nipple . And place in bottle with enough brke fluid to cover hose end,
Then just open bleed nipple and pump brakes till no more bubbles ,
while keeping brake resivor full of B Fluid
Do each wheel
Just keep hose under fluid in bottle,
And resivor from going dry,
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[sqrlnts]

Originally Posted by lazypineapple

R u using a hose and bleed bottle?
If not, get a foot long piece of vacuum hose or like..
Slip hose over bleed nipple . And place in bottle with enough brke fluid to cover hose end,
Then just open bleed nipple and pump brakes till no more bubbles ,
while keeping brake resivor full of B Fluid
Do each wheel
Just keep hose under fluid in bottle,
And resivor from going dry,
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Its funny you mention this method. I did give that a try and it didn't work for me. I think the problem was it pulls air back in between the bleeder screw threads when I released the pedal each time. It must work for some folks cause there are about 50 videos on how to do it this way.

Just realized I didn't replace the PS front wheel cylinder when I did the rest. Going to replace this first, then try to bleed again.

[lazypineapple]

If you are sucking air past the bleeder thread then it will never stop using bubbles out,
You could put heavy grease around bleeder treads so it will not suck air.

If the Master cylinder drained out while having the wheel cylinder off then you may need to bleed MC,
To do this on the truck get a helper.
They push pedal.
You open line at MC.- fluid and air come out.
You close Line.
They let up on pedal.
Repeat
til only fluid oozes out
Then bleed all Wheel cylinders again.
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[Russell Ashley]

I use a vacuum bleeder to initially bleed my brakes after a brake rebuild. Before I start I use Teflon tape on the bleeder valve threads to prevent air leaking around them. I still like to do the final bleed the old fashion way by getting my wife to pump the brakes and hold the pedal down while I check for any remaining air in the system.

[OrrieG]

I did not think you should use teflon tape on brake or gas fittings, gets ate up and develops small leaks??? I have never had a bleeder fitting leak, I think they are either a tapered thread or a flare fitting. I used to use the hose in a bottle method with my wife on the pedal end until she started complaining about her calves getting to big...

[Russell Ashley]

Orrie, it only goes on the threads to keep air from entering around the valve when using a vacuum bleeder. It never comes in contact with the sealing area of the bleeder valve. I too have never had one that leaked when tightened properly.

I use teflon tape on the threads of most every fitting, including brake and fuel connections. It never comes in contact with the fluid being sealed so I have never had any problems. It seems to make them easier to open when or if you ever need to.

I've never heard of teflon tape deteriorating but it opens an interesting discussion topic. Anyone else got an opinion?

[1project2many]

I bleed brakes by myself by wedging a stick on the brake pedal and opening the bleeder. Repeat until air is gone. It does require a few trips back and forth but it always works and requires the least amount of special tools.

I've found bits of teflon tape in fuel rails, calipers, and caarburetors. So I never use it on anything but a pipe thread fitting. There are only a few chemicals which should not be used with PTFE. There's a nice chart here:
http://www.calpaclab.com/PTFE-PFA-an...hart-s/832.htm

[Russell Ashley]

Any sealant can be used incorrectly. I know of one engine that had to be rebuilt because of the "boogers" from excess silicone restricting oil flow. It's all in how you use it.

No, it wasn't my engine and I didn't do it.

[1project2many]

You're right. I've been involved in some warranty fixes that were due to improper use of silicone. In the early days of silicone sealer guys would use way too much and after a while pieces would break off, get into the pan, and plug the pickup tube. What a nightmare. With all that's going the wrong direction these days, engine sealing is vastly improved compared with state of the art in the '40s and '50s.

[coralhead]

Originally Posted by OrrieG

......I used to use the hose in a bottle method with my wife on the pedal end until she started complaining about her calves getting to big...

I had to laugh and send this to my wife. I use the same method.

[Coupeguy2001]

You can bench bleed the master in the truck. You just loosen the output line on the master, (have a drip pan under it) and pull down on the pedal arm. tighten the fitting and let go of the pedal. then pull down on the pedal, and loosen the fitting. Just before the pedal gets all the way down, tighten the fitting. The trick is to suck as much fluid into the master, and then expel it out the end. That way, there will be no air in the line.
I always used to dislike the bench bleed thing because it went all over. using the fitting at the master in the truck for some reason does not create the same mess.
Make sure you start with a full reservoir and keep it full.
You can also use this method to bleed the front left brake, but not so easy with the rest of them.

Also, if you think you have it pretty good, go out and get the brakes hot. the air in the fluid will expand and the hot air rises. In an hour or two, the pedal will firm up on it's own. That is just for minor amounts of air only

[sqrlnts]

Originally Posted by Coupeguy2001

You can bench bleed the master in the truck. You just loosen the output line on the master, (have a drip pan under it) and pull down on the pedal arm. tighten the fitting and let go of the pedal. then pull down on the pedal, and loosen the fitting. Just before the pedal gets all the way down, tighten the fitting. The trick is to suck as much fluid into the master, and then expel it out the end. That way, there will be no air in the line.
I always used to dislike the bench bleed thing because it went all over. using the fitting at the master in the truck for some reason does not create the same mess.
Make sure you start with a full reservoir and keep it full.
You can also use this method to bleed the front left brake, but not so easy with the rest of them.

Also, if you think you have it pretty good, go out and get the brakes hot. the air in the fluid will expand and the hot air rises. In an hour or two, the pedal will firm up on it's own. That is just for minor amounts of air only

Thanks for the advice Chris, how you been? Hows the truck running?

[Coupeguy2001]

running great. going in the direction of rear gas tank maybe next. I removed the under bed spare tire. I was at Pavilions last night with it.