The Ford Barn

Don W/Norfolk · 08-03-2012, 07:37 AM

I have a brake system bleeding problem. I’m out of ideas and need help. (My wife says I need help even why I have ideas, but that is beside the point…)

New system installation in a ’40. Running a Corvette dual master cylinder, residual pressure valves fore and aft, discs up front and drums on the 9" rear. All new lines, calipers, and wheel cylinders. Bench bled the MC before installation.

I intentionally left the right front and right rear lines “cracked”, and after topping off the MC and pumping the brake pedal, I observed fluid at those two corners.

At that point I stopped pumping the pedal and switched to a vacuum bleed system with a Mighty-vac pump. Starting with the bleeder closest to the MC (the lf), I’ve sucked a lot of air and little fluid. Can’t get to a point where it is even 50/50 air/fluid.

I’ve checked all the bleeders closed tight, pumped the pedal and do not observe any leaks (put dry paper down and left overnight – no spots).

All suggestions for a course of action are welcome. dw

Happydaze · 08-03-2012, 07:53 AM

Why not just bleed conventionally?

I don't know anything about these vac thingies but i suspect they'll do a great job of sucking air in around the bleeder threads and out through the bleeder, which of course might explain what you're experiencing.

I've had good experiences with the air fed pressure bleeders but strangely i always resort to the good old manual method.

Chris

okiedokie · 08-03-2012, 08:31 AM

I agree with Chris. I have tried several of the "new" ways of bleeding but have settled on the old way with the exception of having a helper. I originally had a "one man brake bleeder fro NAPA that is a plastic bottle with a magnet attached so it can be held above the bleeder valve. Also has a clear tube with several "ends" to push into bleeder valves. Then you simply pump pedal up, go to the bleeder valve and open the valve and the air is released up into the bottle. Once there is no more air bubbles in the tube, that brake is done. I was in Harbor Freight and saw the same thing for cheap so I bought four new ones and put one on each bleeder valve so I don't have to move one around. This works very well for me.

George/Maine · 08-03-2012, 08:35 AM

If your mc is under floor,try and get the wheels lower by jacking up.
Adjust back brakes.What I do is just crack the bleder little and pump about 10 times when you see if on floor ,let it run by graity and close.Then do others the same way.
I have a Mustang MC with adjustable valve in back.Don,t let MC run dry keep filling,and only push pedal half way down.

ole39 · 08-03-2012, 08:38 AM

i found on my 39 when i put all new everything on it, (all stock) it took awhile to get all the air out, just patience, which i dont have alot of.

Hamtown Al · 08-03-2012, 08:49 AM

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I was told to start at the wheel fartherest from the MC. Then work back. Daddy said to do it that way when I did my first brake job as a teenager... a loonngg time ago!
I don't know if that will make any difference.
Keep in mind that the system could have gotten air back into the lines between the time you let off the brake the last time and then got to each wheel to close the bleeder.
If you are working alone, (aren;t we all?) you might want to invest in the new one way bleed valves that are available in most auto parts stores now. I've not used them but understand that they replace the usual bleeder and will only let air and fluid out and not allow air back in. When finished, you tighten them and leave on the car.
I hope this helps.
Keep working,
Al

51 MERC-CT · 08-03-2012, 09:47 AM

Have virtually the same type system in mine and had some of the same problems bleeding. After installing Speed bleeders the problem went away.

Bob C · 08-03-2012, 10:19 AM

Not that it will affect your bleeding problem but I don't think you want residual
pressure valves on the front disc brakes.

Bob

19Fordy · 08-03-2012, 11:03 AM

Try Speed bleeders. NAPA has them as do many other suppliers. http://www.summitracing.com/search/P...peed-Bleeders/

Bassman/NZ · 08-03-2012, 03:59 PM

Which size is the early Ford one? I'm thinking it's 5/16" ?

41ford1 · 08-03-2012, 04:17 PM

The vacuum pump is where you went wrong. Do it manually. Get your wife to help. She can push the pedal when you tell her to. She won't even get dirty.

gmc1941 · 08-03-2012, 04:23 PM

Cracked new fittings are nortories for allowing air to be sucked in. We always ASSUM that every fitting we did is perfect. The other thing you can do is to remove the the bleeder and put a couple wraps of of Teflon tape on. This way, if the threads are leaking air it will seal the threads.

PeteVS · 08-03-2012, 04:33 PM

Aren't dual master cylinders supposed to be bled on the bench before they're installed??

51 MERC-CT · 08-03-2012, 04:46 PM

Quote:

Originally Posted by PeteVS

Aren't dual master cylinders supposed to be bled on the bench before they're installed??

Read the first post, he said he bench bled it.

PeteVS · 08-03-2012, 05:59 PM

Quote:

Originally Posted by 51 MERC-CT

Read the first post, he said he bench bled it.

That's funny... I read about leaving lines "cracked" and topping off the master cylinder but, I didn't see about bleeding the master cylinder before it was installed? (By the way, I've never done this myself, so maybe I'm way off base.)

al pa. · 08-03-2012, 08:06 PM

sounds just like the setup on my 47 merc.corvette style dual m.c.lid didn't match with the hole in the floorboard,so I got a remote fill,mounted on inner fender,under the hood.No luck bleeding,I think partly because the lines are higher where they split for the front brakes,and the calipers are lower than the lines.I got an $8 walmart pump sprayer,removed the wand,and hooked it to the remote fill hose.I now have about half a pedal as opposed to no pedal.I want to adjust the freeplay,and bleed again with more pressure.I was afraid to blow the hoses apart last time.

V12Bill · 08-03-2012, 08:39 PM

If you "cracked" the rf and rr bleeders and left them like that to bleed the other side, aren't you sucking air into the system via the "cracked" bleeders when you let up on the brake pedal?

Don W/Norfolk · 08-13-2012, 05:10 PM

Just a follow up post.
Thanks to all who offered suggestion. The final solution was a combination of several.
Replaced a defective copper washer at the left front
Installed "speed bleeders"
Pumped, pumped, and pumped some more
Finally have a pretty firm pedal. Want to go round one more time after letting it sit overnight to make sure I've got it all.
Thanks again for all the help.
dw

Hamtown Al · 08-13-2012, 09:52 PM

OK! Great! Now when are you and your lovely wife coming to Smithfield for some ice cream?
I knew you could fix it.
Keep working,

Al

hardtimes · 08-13-2012, 11:21 PM

Hey Don,
Thanks for the update! Good on you for figureing it out! Today, I am at the same situation that you have evidently solved. Started at the furtherest whl cyl and worked to shortest line. Only thing, so far, is a LOT of air, no pedal and an 'asistant' that quit on me and threatened to do harm to the car,etc. Huh, I told her to do her best, as the guy who put this abomination brake system together....had already done the dirty work!!
Hm, since she quit...those bleeders sound pretty good!

08-03-2012, 07:37 AM	#1
Don W/Norfolk Senior Member Join Date: May 2010 Location: Norfolk, VA Posts: 127	Brake bleeding problem I have a brake system bleeding problem. I’m out of ideas and need help. (My wife says I need help even why I have ideas, but that is beside the point…) New system installation in a ’40. Running a Corvette dual master cylinder, residual pressure valves fore and aft, discs up front and drums on the 9" rear. All new lines, calipers, and wheel cylinders. Bench bled the MC before installation. I intentionally left the right front and right rear lines “cracked”, and after topping off the MC and pumping the brake pedal, I observed fluid at those two corners. At that point I stopped pumping the pedal and switched to a vacuum bleed system with a Mighty-vac pump. Starting with the bleeder closest to the MC (the lf), I’ve sucked a lot of air and little fluid. Can’t get to a point where it is even 50/50 air/fluid. I’ve checked all the bleeders closed tight, pumped the pedal and do not observe any leaks (put dry paper down and left overnight – no spots). All suggestions for a course of action are welcome. dw __________________ I love this country; it's the damn idiots running the government I'm afraid of.

08-03-2012, 07:53 AM	#2
Happydaze Junior Member Join Date: Oct 2010 Posts: 20	Re: Brake bleeding problem Why not just bleed conventionally? I don't know anything about these vac thingies but i suspect they'll do a great job of sucking air in around the bleeder threads and out through the bleeder, which of course might explain what you're experiencing. I've had good experiences with the air fed pressure bleeders but strangely i always resort to the good old manual method. Chris

08-03-2012, 08:31 AM	#3
okiedokie Senior Member Join Date: May 2010 Location: Tulsa Ok Posts: 519	Re: Brake bleeding problem I agree with Chris. I have tried several of the "new" ways of bleeding but have settled on the old way with the exception of having a helper. I originally had a "one man brake bleeder fro NAPA that is a plastic bottle with a magnet attached so it can be held above the bleeder valve. Also has a clear tube with several "ends" to push into bleeder valves. Then you simply pump pedal up, go to the bleeder valve and open the valve and the air is released up into the bottle. Once there is no more air bubbles in the tube, that brake is done. I was in Harbor Freight and saw the same thing for cheap so I bought four new ones and put one on each bleeder valve so I don't have to move one around. This works very well for me.

08-03-2012, 08:35 AM	#4
George/Maine Senior Member Join Date: May 2010 Location: Mid coast Maine Posts: 1,878	Re: Brake bleeding problem If your mc is under floor,try and get the wheels lower by jacking up. Adjust back brakes.What I do is just crack the bleder little and pump about 10 times when you see if on floor ,let it run by graity and close.Then do others the same way. I have a Mustang MC with adjustable valve in back.Don,t let MC run dry keep filling,and only push pedal half way down.

08-03-2012, 08:38 AM	#5
ole39 Senior Member Join Date: May 2010 Location: west central ill Posts: 170	Re: Brake bleeding problem i found on my 39 when i put all new everything on it, (all stock) it took awhile to get all the air out, just patience, which i dont have alot of.

08-03-2012, 08:49 AM	#6
Hamtown Al Senior Member Join Date: May 2010 Location: Smithfield, Va Posts: 822	Re: Brake bleeding problem Sponsored Links (Register now to hide all advertisements) I was told to start at the wheel fartherest from the MC. Then work back. Daddy said to do it that way when I did my first brake job as a teenager... a loonngg time ago! I don't know if that will make any difference. Keep in mind that the system could have gotten air back into the lines between the time you let off the brake the last time and then got to each wheel to close the bleeder. If you are working alone, (aren;t we all?) you might want to invest in the new one way bleed valves that are available in most auto parts stores now. I've not used them but understand that they replace the usual bleeder and will only let air and fluid out and not allow air back in. When finished, you tighten them and leave on the car. I hope this helps. Keep working, Al __________________ 36 Fords Rule! Visit at www.36fords.com.

08-03-2012, 09:47 AM	#7
51 MERC-CT Senior Member Join Date: May 2010 Location: East Hartford, Ct Posts: 5,898	Re: Brake bleeding problem Have virtually the same type system in mine and had some of the same problems bleeding. After installing Speed bleeders the problem went away. __________________ DON'T RECALL DOING SOMETHING FOR MYSELF BASED ON SOMEONE ELSE'S LIKES OR DISLIKES

08-03-2012, 10:19 AM	#8
Bob C Senior Member Join Date: May 2010 Location: So Cal Posts: 8,754	Re: Brake bleeding problem Not that it will affect your bleeding problem but I don't think you want residual pressure valves on the front disc brakes. Bob

08-03-2012, 11:03 AM	#9
19Fordy Senior Member Join Date: May 2010 Location: Coral Springs FL Posts: 10,948	Re: Brake bleeding problem Try Speed bleeders. NAPA has them as do many other suppliers. http://www.summitracing.com/search/P...peed-Bleeders/

08-03-2012, 03:59 PM	#10
Bassman/NZ Senior Member Join Date: May 2010 Location: Napier, New Zealand Posts: 2,001	Re: Brake bleeding problem Which size is the early Ford one? I'm thinking it's 5/16" ?

08-03-2012, 04:17 PM	#11
41ford1 Senior Member Join Date: May 2010 Location: ManchVegas, New Hampshah Posts: 1,589	Re: Brake bleeding problem The vacuum pump is where you went wrong. Do it manually. Get your wife to help. She can push the pedal when you tell her to. She won't even get dirty.

08-03-2012, 04:23 PM	#12
gmc1941 Senior Member Join Date: Jun 2010 Location: Palatine, Il Posts: 486	Re: Brake bleeding problem Cracked new fittings are nortories for allowing air to be sucked in. We always ASSUM that every fitting we did is perfect. The other thing you can do is to remove the the bleeder and put a couple wraps of of Teflon tape on. This way, if the threads are leaking air it will seal the threads. __________________ 1939 Fordor Deluxe 1939 Ford Coupe Std 1940 Ford pickup Nothing in life is to be feared; it is only to be understood.

08-03-2012, 04:33 PM	#13
PeteVS Senior Member Join Date: May 2010 Location: FP, NJ Posts: 2,770	Re: Brake bleeding problem Aren't dual master cylinders supposed to be bled on the bench before they're installed?? __________________ Don't never get rid of nuthin!

08-03-2012, 08:06 PM	#16
al pa. Senior Member Join Date: May 2010 Location: pgh.pa. Posts: 321	Re: Brake bleeding problem sounds just like the setup on my 47 merc.corvette style dual m.c.lid didn't match with the hole in the floorboard,so I got a remote fill,mounted on inner fender,under the hood.No luck bleeding,I think partly because the lines are higher where they split for the front brakes,and the calipers are lower than the lines.I got an $8 walmart pump sprayer,removed the wand,and hooked it to the remote fill hose.I now have about half a pedal as opposed to no pedal.I want to adjust the freeplay,and bleed again with more pressure.I was afraid to blow the hoses apart last time.

08-03-2012, 08:39 PM	#17
V12Bill Senior Member Join Date: May 2010 Location: Mt. Holly,NJ Posts: 1,822	Re: Brake bleeding problem If you "cracked" the rf and rr bleeders and left them like that to bleed the other side, aren't you sucking air into the system via the "cracked" bleeders when you let up on the brake pedal?

08-13-2012, 05:10 PM	#18
Don W/Norfolk Senior Member Join Date: May 2010 Location: Norfolk, VA Posts: 127	Re: Brake bleeding problem Just a follow up post. Thanks to all who offered suggestion. The final solution was a combination of several. Replaced a defective copper washer at the left front Installed "speed bleeders" Pumped, pumped, and pumped some more Finally have a pretty firm pedal. Want to go round one more time after letting it sit overnight to make sure I've got it all. Thanks again for all the help. dw __________________ I love this country; it's the damn idiots running the government I'm afraid of.

08-13-2012, 09:52 PM	#19
Hamtown Al Senior Member Join Date: May 2010 Location: Smithfield, Va Posts: 822	Re: Brake bleeding problem OK! Great! Now when are you and your lovely wife coming to Smithfield for some ice cream? I knew you could fix it. Keep working, Al __________________ 36 Fords Rule! Visit at www.36fords.com.

08-13-2012, 11:21 PM	#20
hardtimes Senior Member Join Date: May 2010 Location: South California Posts: 6,188	Re: Brake bleeding problem Hey Don, Thanks for the update! Good on you for figureing it out! Today, I am at the same situation that you have evidently solved. Started at the furtherest whl cyl and worked to shortest line. Only thing, so far, is a LOT of air, no pedal and an 'asistant' that quit on me and threatened to do harm to the car,etc. Huh, I told her to do her best, as the guy who put this abomination brake system together....had already done the dirty work!! Hm, since she quit...those bleeders sound pretty good!