'40 Brake Bleeding

[mike42]

Still having a hell of a time getting brakes to bleed. I tried to look at past threads, but can't find this answer.

Did someone tell me to "adjust the brakes until shoes hit the drums and then bleed......you can always re-adjust afterwards".

That's from memory right now. Am I correct ?

Thx.....Mike

[fortyfords]

Mike, it sounds like you have a leak somewhere or a wheel cylinder has dry rubber cups and is just letting air in every time you release the brake pedal. I would disconnect the brake line from the master cylinder and block the port and see if you get a hard pedal when you bleed. If you do get a hard pedal, then hook up one brake line at a time until you find the one wheel that gives you the soft pedal. Yes, you will have to have some plugs to block off the lines at intersections and at backing plates.

[mike42]

Forty...... thx let me check that out.....also should I adjust the brake shoes out to touch the drums ? I'll buy the plugs today. May not work on it today as we got 2" of snow last night and it's 18º now !!! Geez....

Thx....Mike

[rockfla]

Mike42
Did you just do a "recent" brake job and or replace wheel cylinders by chance??? OR replace shoes???


As for adjusting them, I adjust the bottom first, I bring them out to where they just contact the drum and do a "very slight" back off from touching. Then do the same on the top...just ever so slightly before touching or drag!!!! It shouldn't matter IF you do this before or after bleeding!!!!


The reason for asking the first question IS. I was talking with Mike at Third Gen when I was working on my 39 Merc brakes and he was telling me about "some" of the after market shoes and wheel cylinders THAT the tabs on the shoes where they fit the wheel cylinders are a little long and thus push the cups further inward on the wheel cylinder. It allows for bleed by on the cups and you can't get a hard peddle. IF you did put new shoes and or cylinders on, you might want to pull the rubber caps on the cylinders and SEE IF there in fluid behind them......IF so (and you also replaced your shoes) you may need to pull the shoes back off and grind the tabs back a little bit!!!!!

[mike42]

Rock......I turned drums, replaced shoes and wheel cylinders as well as the master cylinder. i'm getting fluid to each wheel, but will not bleed as they should. I will check the tabs out for sure.

Cold and snow today so when it warms a bit.

Thx....Mike

[rockfla]

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Originally Posted by mike42

Rock......I turned drums, replaced shoes and wheel cylinders as well as the master cylinder. i'm getting fluid to each wheel, but will not bleed as they should. I will check the tabs out for sure.

Cold and snow today so when it warms a bit.

Thx....Mike

Also.....Are you using silicone brake fluid??? That will also make your peddle a little "softer" than normal. I was having the same issue with my Mercury.....BUT Mine ended up just being "lots" of air in the lines!!!! SO i ended up bleeding mine 4 times to get all the air out, finally a really nice peddle even with silicone fluid!!!

[rockfla]

Mike42
Just in case, here is "from the Ford Service" book!!!!

[Alaska Jim]

Did you "bench" bleed the master cyl. before you installed it?

[mike42]

Rock ....thx for pages ! I'm using DOT 3 Fluid.

Alaska....I tried to bench bleed and was not very successful I'm sorry to say. That may be a big part of my problem. I have buddy looking into it now also, as I'm running out of time. As a side note I lived on Ladd Air Force Base in '51, '52 and'53 in Fairbanks. Great part of my life !!

Thx all....Mike

[mike42]

Rock ....

Can you send me those photos a little larger. Very hard to read when printed and some areas don't come out well at all.

[email protected]

Thx....Mike

[glennpm]

My file and edits

[tubman]

I have never had to bench bleed single chamber master cylinders. Didn't that come into practice only after the introduction of dual chamber masters?

[Kube]

Originally Posted by tubman

I have never had to bench bleed single chamber master cylinders. Didn't that come into practice only after the introduction of dual chamber masters?

You are correct sir. There is zero reason to bench bleed a single master unit.

[mike42]

Glenn .....thx !

I worked on it all day yesterday and I'm having a hell of a time getting anything to happen. I don't know. I may take it to my Buddy's Shop and have him see what he can do.

Thx....Mike

[mike42]

Glenn....printed out big and great !

Thx again...Mike

[Kurt in NJ]

I have found that new production wheel cylinders need to be taken apart and inspected, some have the holes drilled wrong, the feed holes drilled off center (cut the shoe tab so the piston is out more to uncover the hole??) and bleeder holes not going to the top of the cylinder --you can't get the air out!!
Even rebuilt ones need taken apart i have had leaks in them because the shavings were not cleaned out

[mike42]

Since the weather has been good I've tried a few more things with no luck at all ! I had it trucked down the my Buddy's shop and we'll see what he can do with it. Would sure love to be driving it with weather like we've had here !

Kurt...I'll mentioned your idea with my friend. Thx...

Mike

[Alaska Jim]

Kube, tubman, I was not aware that the single chamber master cylinders did not need to be bench bled, I have always done it though. thanks for the information, good to know.--Jim

[Talkwrench]

Originally Posted by tubman

I have never had to bench bleed single chamber master cylinders. Didn't that come into practice only after the introduction of dual chamber masters?

correct and dont push them all the way to the floor..
long steady strokes...

[51woodie]

I turned drums, replaced shoes and wheel cylinders as well as the master cylinder. I'm getting fluid to each wheel, but will not bleed as they should. I will check the tabs out for sure.

Mike. I have read this post several times, and I'm not sure what the problem is. You say you can't bleed the brakes properly, so I'm going to assume you can't get a solid pedal. You say in post #5 (as above) that you turned the drums and installed new shoes. Did you have the shoes arced to match the turned drums? I'm only guessing here, but if the shoes don't match the drum radius, and only contact the drum at mid point of the shoe, is it possible that the shoe would flex, like trying to straighten out a curved spring , thus causing a soft pedal?

[35fordtn]

To the original poster are you running reproduction shoes? If so you need to grind .020" off the tabs of the shoes where the cylinder pistons push against. The reproduction shoes are made with the tab too long causing the cups to push in too far into the wheel cylinder. We include a note dictating such in all the shoes we sell. This is only a issue if your drums measure less than around 12.030". What exactly is your issue in not getting them to bleed right? Soft pedal? If it is a soft pedal use good reproduction cylinders and check out the shoe issue I mentioned and you'll be set.

No need as others have mentioned to bench bleed a master cylinder. .... Check for minimal leaks as well! Are you using copper washers between the front hoses and the cylinders? if not, do so.

[mike42]

Woodie.....

I have tried to adjust the new shoes the best I can to answer the question. What I have not done is adjust the new shoes so they touch the drum just enough for wheel not to turn and then try to bleed right rear wheel. That's the next step along with plugging the split-off adapter at rear of the master cylinder so that the fluid only goes to the rears to see if that helps in the bleeding process. My problem also is that the weather has been so nice that I've spent more time cleaning up the property from the Winter mess, but I will get back to it soon. I need to get that car back on the road. I love driving it !!

Thx.....Mike

[glennpm]

Hi Mike,


Regarding shoe adjustment, tighten as you mention but then back them off so the wheel/tie CAN be moved. It may scrape just a bit in one spot but you don't want them so tight that the wheel/tie can't be moved. If you did it that wrong way, as the the drum heats up you will have very heavy drag and could even lock the wheels up just do to the heat expansion.


Glenn

[Bob C]

You say you have a bleeding problem, what exactly is the problem??

[Doublepumper]

Make sure the master cylinder pushrod is retracting completely. There should be approx. 1/4" pedal free movement before the pushrod contacts the master cylinder piston. If this is too tight the piston can't retract fully and you'll have a problem getting all the air out of the system. Also, if driven like this the brakes will drag when they heat up.
Good luck!

[mike42]

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35 ....I may have to pull them all apart to check out the tab issue I can't resolve this. As far as the bleeding....I mist have filled the Master 50 times and started with right rear....I get bubbles and bubbles and bubbles, but never a pure steam of fluid. Sometimes nothing comes out. Pedal goes right to the floor ! New master and all new wheel cylinders.

Glenn ....I'm going to try that tightening next. Car is at my buddy's shop and he's looking at it also.

Bob .....all new cylinders and shoes and cannot get a good solid flow of fluid no matter how many times I pump the brakes. Pedal got right to the floor. I keep refilling the master and get a flow with bubbles, but then nothing. Put in more fluid and same old things !!

Double .....I'm checking that 1/4" clearance out for sure.

Thx....Mike

[mike42]

PS - I'm using a very good vacuum pump that gives up to 25 lbs. of pressure and still no luck.

[fortyfords]

When you are having this much trouble, you don't want to use a vacuum pump, you have to have pressure so you don't draw any air in through a minute leak. Otherwise you will be chasing your tail forever. You are probably getting the bubbles by air being sucked in past the threads of the bleeder screw and a little bit from where the bleeder hose is connected to the bleeder screw. So remove the bleeder screw and put teflon tape around the threads and screw in partially, Blue monster on the threads is good also. Once you get no bubbles, that bleeder can be screwed in and go to the next one. Don't pump the brake pedal either, just have someone hold the pedal down lightly. Give that a try

[Hal Beatty]

Speed Bleeders work great, at least in my opinion. Put some teflon tape or paste on the threads when you install them and bleed away...

[JSeery]

Originally Posted by mike42

PS - I'm using a very good vacuum pump that gives up to 25 lbs. of pressure and still no luck.

Sounds like the method may be part or all of the problem. I like to step on the pedal (requires a helper) and then crack the bleeder screw for just a second or so. Re-tighen it, have the helper let off the pedal, than step on the pedal again and repeat the process. Some times I have to except "as good as I can get" and move to the next wheel. After two or three times around they should be firm if there is not another issue.

[1931 flamingo]

I'm in CT but is there anyone close to mike42 who could physically help????

Thanks, Paul

[mike42]

Morning guys......

I'm going to use the sealer material for bleeder vales for sure. That was never mentioned before. I think I have a tube of that and will look today.

Hal.....I am using Speed Bleeders which surprises me that I having so much trouble.

The one thing I not doing is having someone pump the brake to help me. Rather I've been using the Vacuum pump and maybe that is my whole problem. My next step is to block off the front brakes via the split fitting at end of Master with a plug and see if I can get the backs bled with a friend of mines help.

The drama goes on for sure, but thx for all the suggestions and help !

Mike

[Ggmac]

Dump the vacuum. I work alone and have just done a complete brake system replacement on my new to me 41 . I also did the lines . I fabricated a broom stick to hold the pedal down . Its placed on the bottm front of the seat . As a mechanic , we had a locking extension rod that was used for this purpose.
Just push the pedal down , insert rod and go bleed . Short releases of fluid . As the pedal gets firmer and higher , adjust the seat to fit your rod .

[glennpm]

Hi Mike,

Looked back through this whole thread and don't see that you mention if you have a hard pedal even though you are seeing bubbles. Is the pedal firm?

The reason I ask is that I'm a one man "shop" myself and use a vacuum pump for bleeding most of the time. When bleeding with the pump you will see bubbles with vacuum if you only just crack open the bleeder. I put a box wrench over the bleeder, positioned so I can get a good quarter turn on the bleeder, then slide a hose over the bleeder. Probably at least most of the time, I can get a steady fluid stream by turning the bleeder about an 1/8 of a turn.

After I bleed the brakes, I let it sit over night with a 2X4, keeping pressure on the pedal by bracing off the seat like Ggmac says. This keeps the Master cylinder port open with the system under pressure, air bubbles will migrate into thee master cylinder.

Glenn

[46woodie]

Perhaps drums have been turned too large?

[mike42]

Will answer more later as I have had to spend time cleaning up the property from Winter storms and the place is a mess. Snowing again today for second time this week. I'll be getting back to the car soon though. I can't do it all at the same time.

Mike

[mike42]

Glenn ....I do like the 2x4 idea !!

[glennpm]

Yeah, it works good for the final bubbles.


Glenn

[JSeery]

But it is SO much easier with two people!

[Clem Clement]

Mike 42
I spent a lot of time at Eilson AFB, Fairbanks, flying north. 61-63.Weather recce and sniffing. Clem

[Clem Clement]

I have DOT 5 in my '39 Pickup brake system. Why are members having trouble bleeding? I usually ask Sandy to pump and hold the break pressure on and ease the bleed-valve open, listen/watch the small stream of DOT 5 , and close the fitting before the pedal hits the floor.
V/r,
clem

[Clem Clement]

why are some folks having trouble bleeding brakes? I have DOT 5 in my '39 pickup. I ask Sandy to pump and hold pressure, open the bleed valve slightly, watch/listen to the liquid stream, close the valve before the pedal hits bottom.
V/r, Clem

[19Fordy]

Be sure to follow the directions posted earlier by rockfla as found in the manual shown below. I use a 2x4 and a bathroom scale to obtain 35 pound reading. I also use Speed Bleeders and make sure the master cylinder never runs dry. When bleeding, press the pedal slowly down each time so as not to introduce any air bubbles.

[mike42]

Clem .....

I lived at Ladd AFB Strategic Air Command in '51, '52 and '53. My Dad was Adjutant General of the base. I was 9 years old when we got there. He also flew the B-52's and F-86's

Great time of my life !!

Mike

[mike42]

Clem ....

I just had a hell of a time getting them to bleed until I got the Pressure Tank. First time I used it they were solid !

Mike

[V8COOPMAN]

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Originally Posted by mike42

Clem .....

I lived at Ladd AFB Strategic Air Command in '51, '52 and '53. My Dad was Adjutant General of the base. I was 9 years old when we got there. He also flew the B-52's and F-86's

Great time of my life !!

Mike

Your Dad sounds WAY-COOL!

You should recognize THIS "car-guy"! DD

[Clem Clement]

V8COOPMAN,
I started out flying the WB-50 for the Air Weather Service. I have 4 in flight penetrations. Loved the shake and bake. Then some time in Tac Tackers in Thailand, C-47's in Hawaii and Convairs in Alabama and Germany. I miss the early morning launches with the sun not up yet and the dew running down the bird.

(Night landings and day landings are the same b except you can't see at night.(:>))

[Clem Clement]

When tightening a weeping front brake line, the hose twists. Is there a sliding fitting to prevent this?

[mike42]

V8 ….. sorry don’t recognize the guy in photo.

[glennpm]

Grouco Marx with his signature cigar?


This is an interesting Marx brothers race:


https://justacarguy.blogspot.com/201...-brothers.html

[mike42]

I'll check it out !

[V8COOPMAN]

Originally Posted by mike42

V8 ….. sorry don’t recognize the guy in photo.

That is General Curtis Lemay. He became the original Commander of SAC, the Strategic Air Command from 1948 thru 1957. He then became Air Force Vice Chief of Staff. He took over Command of the B-29 program in the Pacific during WWII. He oversaw dropping the A-bombs. Before the Pacific, he had developed the bombardment tactics that left Germany in rubble. He organized the Berlin Airlift. In 1961, he became Air Force Chief of Staff. He served as a General for seventeen years....longer than any other man in US Military history. He was one bad hombre! Look-up some of his many infamous quotes (link below) which I can't print here.

https://www.bing.com/images/search?q...mageBasicHover


He was huge into sports car racing, introducing SCCA sponsored racing on USAF bases. He once wrecked a turbine-powered Allard that he couldn't get stopped.







Sitting in his own Allard with another driver.





.

[Mart]

Originally Posted by Clem Clement

When tightening a weeping front brake line, the hose twists. Is there a sliding fitting to prevent this?

You should loosen the other end so the hose can rotate and when the wheel cylinder end is fitted ok, then tighten the other (chassis) end.

[19Fordy]

We need General Lemay today more than ever.

[Fairlane500]

Just had this same issue and trimming the shoes remedied, worth bringing this thread back into the main for others to see. Only took about 1.5mm off each shoe. Bit more than the 20” but got a good result with new cylinders, shoes and drums.

[Tinker]

The ability to arch shoes are a lost art since the 50-60s.... The machines pop up sometimes on craglist for arching shoes.


this post is chuck norris approved...

[glennpm]

[QUOTE=V8COOPMAN;2052347]That is General Curtis Lemay. He became the original Commander of SAC, the Strategic Air Command from 1948 thru 1957. He then became Air Force Vice Chief of Staff. He took over Command of the B-29 program in the Pacific during WWII. He oversaw dropping the A-bombs. Before the Pacific, he had developed the bombardment tactics that left Germany in rubble. He organized the Berlin Airlift. In 1961, he became Air Force Chief of Staff. He served as a General for seventeen years....longer than any other man in US Military history. He was one bad hombre! Look-up some of his many infamous quotes (link below) which I can't print here.


Great history Coop!

[Terry,OH]

Is there a source for a steel master cylinder cap to convert it for a pressure bleeder? All I have seen are original white metal style

[mike42]

Coop……I remember Lemay making a visit to Ladd back in the day. It was a very BIG deal when he came in. I have a photo of my Dad on a microphone making a speech in a Grand Stand set up on the taxi area of the airfield.

Haven’t heard that name in a long time.

[Clem Clement]

General LeMay was a great leader. When he noticed some of his troops were getting into trouble, he directed that every base have a auto hobby shop. On travel he used to visit the shops. I had many happy hours in USAF auto shops.

One time while TDY to Germany, the General was met by a WWII buddy riding a motorcycle. When he brought the bike back, he asked the guy if he was worried about the General? No, i'm worried about my bike...

[mike42]

Clem …..I can remember my Dad saying he was a no bullshit guy !

[V8COOPMAN]

Originally Posted by mike42

Clem …..I can remember my Dad saying he was a no bullshit guy !

And that's no bullshit! DD

[Cadillac_chris]

Have you tried a pump or gravity bleeding

[Clem Clement]

Another Lemay story: The General was inspecting a row of alert B-47's with a lit cigar in his mouth. The young airman security guard blocked his way. " no smoking near these aircraft General! The aircraft might catch fire" Supposed the General said "they would not dare!" The airman got a spot promotion

[V8COOPMAN]

Originally Posted by Clem Clement

Another Lemay story: The General was inspecting a row of alert B-47's with a lit cigar in his mouth. The young airman security guard blocked his way. " no smoking near these aircraft General! The aircraft might catch fire" Supposed the General said "they would not dare!" The airman got a spot promotion

Ya know Clem, I've probably read that story at least a hundred times or more. Different aircraft types, as the story went, but the same "They would not dare" consistently. Very likely a true story at some (or several) time(s)! DD