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Soft Brake Pedal after bleeding 3 times?????

Posted By: HelleOnWheels

Soft Brake Pedal after bleeding 3 times????? - 11/20/11 02:37 AM

Car is a 67 RT with manual drum brakes. I installed a new master cylinder, new lines and new wheel cylinders. The only parts that were re-used were the brake safety switch (manifold) and the rear axle distribution block.

I started by doing a bench bleed on the master and it seemed to go fine. Kept pumping until all the bubbles had gone away. I let it sit overnight and pumped it again just to make sure. I installed it on the car and hooked up the new lines and wheel cylinders. I hooked up hoses to each of the bleeder screws and let them gravity bleed into small cups. After I had a nice flow coming out in each of the cups, I closed the screws. SOFT PEDAL!!!

I decided to go the old fashioned way and got a buddy and a cup of fluid. I started at the passenger rear and put the bleeder hose into the cup of fluid and had buddy press brake pedal until I had no more bubbles and had a nice flow of fluid that was rising in the cup. Went around and did all of the rest of them the same way. SOFT PEDAL!!!

Did it again with the cup.....SOFT PEDAL!!!

What in the world am I doing wrong? This is my first time bleeding 4 wheel drum brakes, but not my first time working on a car!!!!

I don't see any leaks anywhere and am not losing fluid when I drive it around the neighborhood.

Any thoughts?
Posted By: RapidRobert

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 02:50 AM

I'd get 2 brass male inverted flare plugs from the "Edelman" cabinet at your parts house of the dia of the M/C ports (maybe 2 diff dia's) and take the lines back off & plug them. They're cheap & you WILL use them for diagnostics in the future. If the M/C is good (& bled out) the pedal will now be rock hard w virtually no travel. If good there take out the rearmost brass plug & hookup & bleed out the fronts & get them till the pedal is again high and tight then hookup the rear drums & same deal. The only caveat I can think of happening in the procedure is if a bleeder screw(s) ain't being closed all the way before your helper lets up on the pedal.
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 02:54 AM

Are all 4 drums adjusted properly?

Have your buddy pump the pedal (with the car running if it has power assist) about 5 times and then hold it. While he is holding pressure on the pedal, open the bleeder (his foot should go down) and then close the bleeder before he lifts his foot off.

Repeat this process 3 times at each wheel then check the pedal. It may even take one more go around (3x's each wheel).
Posted By: BRONZEBEE

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 02:56 AM

Pump 3 times with bleeder closed,hold pressure on pedal then crack bleeder.start with the right rear and work your way to the front.keep checking master cylinder level, don't let it go dry.
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:01 AM

Quote:

I'd get 2 brass male inverted flare plugs from the "Edelman" cabinet at your parts house of the dia of the M/C ports (maybe 2 diff dia's) and take the lines back off & plug them. They're cheap & you WILL use them for diagnostics in the future. If the M/C is good (& bled out) the pedal will now be rock hard w virtually no travel. If good there take out the rearmost brass plug & hookup & bleed out the fronts & get them till the pedal is again high and tight then hookup the rear drums & same deal. The only caveat I can think of happening in the procedure is if a bleeder screw(s) ain't being closed all the way before your helper lets up on the pedal.



Thanks...I will be trying this tomorrow
Posted By: DAYCLONA

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:05 AM

All of the above is good advice, but keep in mind that if your adding the spent fluid from the container that your bleeding each wheel with to re-fill the master, your adding air entrained fluid (microscopic air bubbles) back into the brake system, possibly causing an airbound pedal, always replenish the master with fresh fluid
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:06 AM

Quote:

Are all 4 drums adjusted properly?

Have your buddy pump the pedal (with the car running if it has power assist) about 5 times and then hold it. While he is holding pressure on the pedal, open the bleeder (his foot should go down) and then close the bleeder before he lifts his foot off.

Repeat this process 3 times at each wheel then check the pedal. It may even take one more go around (3x's each wheel).



Question for you....here is my exact steps when at each wheel cylinder
1. Put hose on bleeder screw and into cup making sure it is below fluid level in cup.
2. Crack bleeder screw open
3. Tell buddy to press on brake
4. He keeps pumping until I do not see any bubbles(approx 3 times.
5. Tell buddy to hold pedal down after last pump and then I close bleeder screw.

Move to next wheel


I noticed that you said have him pump brake pedal a few times and THEN crack the bleeder screw.

I was cracking the bleeder screw and THEN pumping it...the closing it..

Is this why I am screwing it up?
Posted By: GO_Fish

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:06 AM

Quote:

Are all 4 drums adjusted properly?

Have your buddy pump the pedal (with the car running if it has power assist) about 5 times and then hold it. While he is holding pressure on the pedal, open the bleeder (his foot should go down) and then close the bleeder before he lifts his foot off.

Repeat this process 3 times at each wheel then check the pedal. It may even take one more go around (3x's each wheel).


, helper has to pump the pedal 3 or 5 times and hold down while you crack the bleeder, then retighten it before he lets off the pedal. AND the brake shoes need to be adjusted close before this starts. You sound like you are on the right track, but execution may be a little off. I've been there!
Posted By: DAYCLONA

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:19 AM

OK so your issue was procedure in bleeding....



As stated have your helper pump up the brakes several times, then crack the bleeder, making sure your helper is pushing the pedal ALL THE WAY to the floor, and HOLDING IT, until you yell out "PUMP IT" to repeat the process, and make sure your assistant holds pressure and follows the pedal to the floor when you yell out "HOLD IT"....you wouldn't believe how many times a helper can FUBAR this operation, esp if it's the wife DAMHIK...take your choice in starting at either the front or rear, but in any case start with the wheel FARTHEST from the master, or with the longest brake line from the master...goodluck
Posted By: B5 Bee

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 03:21 AM

I was cracking the bleeder screw and THEN pumping it...the closing it..

Is this why I am screwing it up?



YES.

Pump till you get the best pedal possible, then crack open the bleeder, the pedal will go to the floor, hold it on the floor, close bleeder, release pedal.
Repeat process till the pedal is firm.
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 04:04 AM

Quote:

I was cracking the bleeder screw and THEN pumping it...the closing it..

Is this why I am screwing it up?



YES.

Pump till you get the best pedal possible, then crack open the bleeder, the pedal will go to the floor, hold it on the floor, close bleeder, release pedal.
Repeat process till the pedal is firm.






If you pump the pedal while the bleeder is open you will back suck air back into the lines. You need the pressure of the fluid to force the air out and it must be a 1 way path. Best way to ensure this s to close the bleeder before your partner is to the floor on the pedal.
Posted By: 6PakBee

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 07:04 AM

It may help to start with the shortest line first rather than the longest line. As to the procedure, using the "pump and hold" technique, my wife and I can usually bleed a set of brakes easily in 30 minutes or less depending on how many components were worked on.
Posted By: therocks

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 01:11 PM

I never like the pedal to go all the way to the floor.You can damamge the master that way by pushing it too far.I always just have the pusher apply light pressure after the pump and then open the bleeder and have them push it lightly down.That way you can damage the master seals.Rocky
Posted By: RapidRobert

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 04:33 PM

Quote:

I never like the pedal to go all the way to the floor.You can damamge the master that way by pushing it too far.

I'm glad Rock brought that up. I place a block of wood under the pedal (of the correct thickness) so the cups do not get pushed past their normal wear area which can hasten their demise and the block as a stop gives you better control of the stroke (it wont be moving back up a bit which can pull air bck in) like it could if doing it by hand and just using your foot w no wood you'll likely go too far
Posted By: 70Cuda383

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 04:55 PM

lots of good information on the pedal pumping procedure, but only one or 2 mentions of the shoes themselves.

the reason it's important to check the shoes for proper adjustment, is because unlike a disc where the pad "floats" right at the disc with no return spring, a drum brake has springs to physically pull the shoes away from the drums.

if you do not have the shoes adjusted properly, so that they are ever so slightly dragging on the drums, then your return springs are pulling them to far back in and the wheel cylinders are being "fully compressed"

when you pump the pedal, what you THINK is a soft pedal from air in the system could actually just be the airgap between the shoes and the drum being taken up by pedal stroke.

add in the fact that all 4 of your wheels are drums, and it's even that much more critical that your shoes are properly adjusted and seated.

--jack on one wheel at a time, have a helper step on the pedal to push out on the shoes, then grab the wheel and try turning it back and forth. this will help to seat the shoe. then release the pedal and click out on the adjuster.

this may need to be done a few times if the shoes are new, as the high spots will wear away quickly, and the brakes will go out of adjustment very fast until the shoes fully bed themselves to the drums.
Posted By: Challenger 1

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 09:32 PM

Quote:

It may help to start with the shortest line first rather than the longest line. As to the procedure, using the "pump and hold" technique, my wife and I can usually bleed a set of brakes easily in 30 minutes or less depending on how many components were worked on.



I also would recommend checking the brake drum adjustment.

I used to have my girlfriend and then wife help me bleed brakes.
We get divorced and get back together after 20 years and we are talking. She said she would help me do anything except bleed car brakes. Out of nowhere she say's this. She even told her daughters to never help bleed brakes.
I guess I really got frustrated when she helped me?
20+ years ago I was given a old pressure brake bleeder, and it has turned out to be one of the most useful tools I own.
It'll bleed anything 100% every time the first time with one guy in minutes not hours.

Freshly rebuilt with new hose and hardware in this picture. The guy who gave it to me thought the rubber diaphragm was shot in it. It wasn't and I have had it apart about 3 times in 20+ years to paint it and to maintain it. Diaphragm is still good and probably will last forever. I store it with fluid in it and under pressure. I have many different MC adapters for different MC.
Top half holds 1 gallon of brake fluid and the bottom half get's pressurized to 25 psi. There's never any contact of the air to the brake fluid this way. Better than those plastic pump up pressure bleeders that pump air into the brake fluid.




Posted By: 70runner

Re: Soft Brake Pedal after bleeding 3 times????? - 11/20/11 11:51 PM

Great thread - tech archives?

I have a completely new brake system in my 70RR, front disks/rr drums, so this will come in handy. Does anyone know the approx system fluid capacity?
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 12:17 AM

Quote:

Great thread - tech archives?

I have a completely new brake system in my 70RR, front disks/rr drums, so this will come in handy. Does anyone know the approx system fluid capacity?



I'm glad my ignorance/inexperience has brought us this great thread , but I would rather my ignorance NOT be memorialized in the tech archives!!!!
Posted By: 70runner

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 12:35 AM

There's really no such thing as an ignorant question in this forum. In my case, I've been bleeding brakes on mopars for 30yrs and I learned a couple things in this thread. Some sharp folks around here.
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 12:54 AM

Quote:

There's really no such thing as an ignorant question in this forum. In my case, I've been bleeding brakes on mopars for 30yrs and I learned a couple things in this thread. Some sharp folks around here.

Thanks!!!
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 01:25 AM

No sir,

Ignorant would have been to keep going the way you were never asking for any assistance and assuming you knew it all.

Have you gotten a chance to adjust and re bleed them yet?
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 02:02 AM

Quote:

No sir,

Ignorant would have been to keep going the way you were never asking for any assistance and assuming you knew it all.

Have you gotten a chance to adjust and re bleed them yet?



Not yet....We are in the market for a new home and were out shopping most of the day.

I am planning on doing them tomorrow night after work with my dad....a little father/son brake job bonding
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/21/11 02:09 AM

Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/22/11 12:31 AM

Posted By: Moparmick

Re: Soft Brake Pedal after bleeding 3 times????? - 11/22/11 12:40 AM

The ONLY ignorant or dumb question is the one you don't ask
Posted By: wheelsup68dart

Re: Soft Brake Pedal after bleeding 3 times????? - 11/22/11 03:21 AM

I know the way you are describing to bleed the brakes and it will work as you stated if you do one more step. The cup with your brake fluid must be held above the the bleeder screw itself. If I am understanding your procedure properly you are attatching a hose to the bulb of the bleeder, opening bleeder, pumping brake pedal to force air out and suck fluid back in. Then close bleeder. Like stated, your results will be better if cup with fluid is above, not below bleeder. I do prefer to use the traditional method of pumping three times, holding, cracking bleeder, closing, release pedal. Repeat till no air seen. Another vote here to put plugs in M/C and pump slowly till you should feel the pedal get very firm. And very good advice to not push the pedal all the way to the floor when bleeding as it can damage the seals in the M/C. If you need to isolate the wheel affected you can clamp off the rubber hose at the rear splitter and see if the pressure gets better, indicating air in rear. Same applies to each of the front hoses. And other good info regarding brake shoe adjustments.
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/23/11 03:14 AM




Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/23/11 05:30 AM

Alright...so here is the deal....I bled the brakes the way it has been described in this thread and thinks went a little smoother.

The only problem is.......I have NO IDEA what the brake pedal should feel like on a 4 wheel manual drum brake car.

I am used to driving power disc brake setups and understand that there is a difference in feel, but I am not sure how it should feel.


Seems like it got softer after moving from the rear to the front....

Tips??
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/23/11 05:40 AM

How many times go you go back around each wheel?

Sometimes it takes going from RR, LR, RF, , LF and then checking the adjustment on all 4 and doing it again.

Sometimes I will adjust the drums really tight to bleed and then back them off to the proper adjustment afterwards.

As for how it should feel, I haven't done a 4 wheel drum system in many years so I couldn't help without being there and or driving it.

Sorry.
Posted By: RapidRobert

Re: Soft Brake Pedal after bleeding 3 times????? - 11/23/11 05:48 AM

Quote:

Seems like it got softer after moving from the rear to the front....

Tips??

spoon all 4 corners tight till the drums are locked. This is imp as it shifts all parts into place/takes out slack. (re) bleed all 4 longest to shortest till the pedal is high and tight. Up on jack stands loosen each front drum till as you hand turn the wheel forward you hit the spot where it turns free and there is one point in the circumference where you hear (but dont feel it slowing the wheel down) a slight "tick" during the revolution of the wheel (when you get close you can go back & forth to get it spot on). Do the fronts then start on the rears with heavy duty jack stands under the axle on each side and your heavy duty hyd floor jack under and just barely touching the 3rd member in the middle of the rear axle for addt'l safety then a helper in dr seat eng idling in drive and rear wheels off the ground. You loosen the star till the wheel starts to turn (loosen both if sure grip) then he hits the brake to stop the wheel(s) you adj loosen more & back & forth safety first until you on each side hit the same sweet spot as the fronts where you hear the "tick". Then Google brake break in procedure and take it out to a secluded hiway & burnish them in then recheck/restore the prior "tick" adjustment
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/24/11 04:53 AM

Spent alot more time adjusting each wheel and making sure they were closely matched to each other. Went around and bled the wheels again and it is much better.

Took it out for the first time in 12 years and things went great

The only thing I noticed was that I have no dash lights

Now on to the next issue....at least this one wont keep me from driving it!!!!

Picked up my passes to the Turkey Rod Run on my test drive and things are looking great for my weekend!!!!!
Posted By: WILD BILL

Re: Soft Brake Pedal after bleeding 3 times????? - 11/24/11 05:26 AM

Quote:


Took it out for the first time in 12 years and things went great






That's what I like to hear

Have a happy Thanksgiving
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/24/11 01:38 PM

Quote:

Quote:


Took it out for the first time in 12 years and things went great






That's what I like to hear

Have a happy Thanksgiving




Thanks Bill!!

Hope you have a Happy Thanksgiving as well!!!!
Posted By: 70Cuda383

Re: Soft Brake Pedal after bleeding 3 times????? - 11/24/11 01:52 PM

Glad you got it worked out!

manual brakes should DEFINITELY have a firm brake pedal. but, how firm depends on what size master vs what size wheel cylinders. you can "soften" the brake pedal by going to a smaller master or larger wheel cylinders, and doing so will also increase your brake effort without increasing pedal feel/leg input.

go drive that car!
Posted By: HelleOnWheels

Re: Soft Brake Pedal after bleeding 3 times????? - 11/24/11 03:16 PM

Quote:



go drive that car!



You don't have to tell me twice!!!!!
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