Wheel cylinders not touching brake shoes

I am running 1939 juice brakes with new stock master cylinder and new wheel cylinders. There are no residual valves except what comes in the mastercylinder. I have done the full brake adjustments and have the shoes fitting great. but the pedal goes to the floor when i step on it. I pulled the drums and looked at the wheele cylinders and there is a quarter to half inch gap between the wheel cylinders and the shoes where they should make contact on both sides. I would think these should always have contact. How do i get rid of this gap? I thought of adjusting the master cylinder push rod to open up the wheel cylinders but that doesn't sound totaly right to me. I also was considering a aftermarket residual valve, but that seems like a bandaid. what would be the correct way to take up this gap between the wheel cylinder and the shoes?
Thanks
Kfleck

 

Welcome from Oregon! but where is your intro? read the sticky..

 

This sounds Messed Up! Your fix is also very wrong. How about you post a photo so we can help you with some near correct information.
The Wizzard

 

Do you have that single spring in place across the top of the shoes that retracts them and keeps them tightly against the wheel cylinder ? Also there is a difference from the 40-41 shoes and the 42-48 shoes (I am doing those years from memory and could be slightly wrong) But the early ones have 4 adjusters on the backing plate and the later ones have only two.

Post some good pictures of what you have, showing the shoes in place. BTW, didn't juice brakes on Fords not start until 1940 ?

Don

 

I will get some pics up as soon as i can. I did an intro four years ago.

Yes the shoe return spring is attached. these are the 39-42 style with 4 adjusters. two on bottom and two cams up on the sides. when the shoes are adjusted per every other thread on the hamb. the cams on the sides hold the shoes off of the cylinders.
I would think the cyliners should come out to meet the shoes.

 

Start with bottom adj. first---then bring top out to final adj.
Make sure wheel cyl. are new or good rebuilds.

 

Thanks Deuce Daddy Don, that’s the way I originally did the adjustment but it’s the opposite of every other thread on here that says to do the top first. Adjusting your way does give me a better pedal.

When I bring the top out, the shoes leave (come off) the cylinders. The upper adjuster cams are holding the shoes off of the cylinders.
I could back off the cams till the shoes are touching the cylinders again and do the full adjustment from the bottom.

This is the adjustment procedure I used.
http://www.jalopyjournal.com/forum/showthread.php?t=476016&highlight=juice+brake+adjustment
I would think with a working residual valve the wheel cylinders would expand to meet the shoes?

 

Don, Ford first used juice brakes in 1939. The backing plates and other hardware were the same as '40 but the drums were 5 on 10 1/4.

Charlie Stephens

 

OK fine, you have your shoes adjusted. Why are the cylinders not coming out to meet the shoes, and staying there?

Did these brakes bleed normally? Anything weird happen during the bleeding process?

I had a '40 brake setup once that I bled before I adjusted the shoes out, and it let fluid get on the wrong side of the rubber cups inside the wheel cylinder. The lip of the cup was covering the inlet hole inside the cylinder, so fluid leaked out the boot of the cylinder.

Not saying yours is doing the same, but maybe you have a cylinder not "pumping up" like it should?

I do use a 10 pound residual valve on the brakes, but that is because the wheel cylinders are higher elevation than the master. It keeps the fluid from leaking downhill (supposedly).

Some wheel cylinders (do early Fords, I don't remember?) have a light coil spring inside to keep the cups pushed out to the shoes. This might be a bandaid fix for yours.

 

they seemed to bleed fine. I got a little air then nothing but fluid for a few more pumps. With all but one drum on I can watch the wheel cylinder expand hit the shoes then move the shoes. when i let off it shrinks all the way back into the cylinder.
with the drums on all the shoes make contact just before the pedal hits the floor.

I think these should have a spring in them but being new I didn't take them appart to see. I will do that tonight and re-bleed to see if there is even a spring in there.

I'm also starting to question weather the stock style master cylinder has any type of residual valve in it. the master cylinder is under the floor but the truck isn't lowered. so they are probably about even. might be a good idea to just put a residual valve in it.
Thanks for the thoughts Alchemy

 

Just a thought........
The edges of the shoes, are not resting on a worn spot or in a gouged out spot, on the backing plate, are they?

 

your wheel cylinders should sit against the shoes in the rest position.the little spring behind the piston should provide enough pressure to ensure that. if they are withdrawing further Id guess the springs are missing,or there is some reverse suction occuring in the master due to a blocked port maybe?

 

Sounds like no residual pressure valve or valve in M/C no operating

 

Measure your brake drums, they should be no more than 12.060".
The brake return spring should keep the shoes snugly against the cylinder rods.
The shoe heel(lower) adjustment should be done first, then the gross adjustment up top.
If your drums are way overturned you'll need new drums which are available from Dick Spadaro parts among others.

 

The wheel cylinders do not touch the shoes.

There should be a short rod that fits inside of the cyl. and connects to the shoes.

 

The 39-40 wheel cyl did not use push pins between cyl piston and shoe. There is actually an ear on the brake shoe that goes in the cyl. See photo. You probably have 2 different style brake systems trying to make one. It won't work.
The Wizzard

 

Crap, photo didn't follow. Try this one.

 

Thanks for the Info guys.

The shoes aren't on the backing plates any more but I will double check this when they are back on.

There are springs in the wheel cylinders. i pulled them out and compared them to the older springs that i have and they are longer and not as stiff as the old ones. so in go the old ones. It sure seems like everything new that I buy is just crapy.
I have not had a chance to re fill the brakes with fluid yet. And will hopefully get to that tonight. I am also going to stop by napa or shucks today and see if I can get a residual pressure valve here in town. Since the fluid is out I might as well splice in some RPV’s

I will measure my drums tonight also and make sure they are within tolerance.

There don’t appear to be any rods. the parts breakdowns that I have found don’t show any rods. there also werent any rods when i disasembled them. so i'll do some research on that but i don't think these should have rods.
thank you again for the info if different springs and residual pressure valves don't do it I will be taking another good look at the "new" Master cylinder. oh yea and sorry again for no pics.

 

That pic is the rear of what I’m working with. Looks identical. Mine are not the shoes with a weird notch in the top for push pins (rods). I’m pretty sure I know what your talking about. Mine are the right shoes for the cylinders. It is definetly a matched set. Thanks you for the pic.

 

I bet a NAPA doesn't carry anything like that, but it's worth a try. If you need to mail order, get a 10 lb. one (single line master, right?) of these:

http://www.ecihotrodbrakes.com/discbrake_kit_components.html

It's brass and much stronger than the aluminum housing kind that many other suppliers sell.

 

What your working with here is the most basic of Hyd systems. If you start adding valves in line that are not necessary your just going to add another problem. You have a problem that I have no answer for but will tell you this. In a correct working Hyd system like this there should be NOTHING that would cause the wheel cyl pistons to retract on there own. It takes the springs on the shoes to return them when things are right. I would be suspect of the master cyl making a Vacuum that is pulling the pucks back or something real Goofy like that happening. The wheel cyl pistons should stop moving when there is no pressure on either side period. To test the Master I would put some pedal pressure on and when the wheel cyl moves brake the line loose at the Master and see what action happens at the wheel end.
The Wizzard

 

thanks Pist-n-broke i will push the pedal down pull the line and let off the pedal to see if the fluid sucks back into the line. with the line open I'm not sure how it should react, but if it sucks way back in there then that would be a step toward checking the master cylinder. i'm really starting to regret puting new parts on this instead of rebuilding the old ones. I'm still up in the air about RPV's they werent there stock so why should they need to be there now. I just figure they couldn't hurt.

 

9-10 you are not bleeding your brakes correctly and you still have air trapped.. You will need assistance in doing the job and if you say that you can see the pistons operate that tells me you are not doing this correctly as the drums must be installed and they cover up viewing the cylinders.

Step one Adjust brake shoes anchors so the brakes are tight, slowly depress brake pedal to fill wheel cylinders,release and return pedal slowly to up position, now depress pedal fully until it stops and bleed furthest wheel cylinder for air while holding pedal under pressure. Make sure you close off bleeder valve before releasing pedal pressure and DO NOT pump pedal, one easy push downward is all it takes. Repeat process at the next furthest cylinder and repeat process. Down, hold, open bleeder, close bleeder, return pedal. repeat all 4 wheels. Now back off brake anchors and adjustment cam and re adjust shoes. To do this apply slight pressure to the brake pedal like 20lbs by using a stick or brace from the pedal to the seat, just something to maintain a slight pressure on the master cylinder. Your shoes should be adjusted from the bottom first and is indexed by rotating the pins from the center out ward of their respective side until you can hear the shoe drag on the rotating drum. Lock the lower bolts and repeat with the upper cams, the upper cams also index by rotating from the center to the outward edge. rotate the upper cam so you can just hear the shoe drag on the drum and you should be good to go. Release the brake stick and check your pedal , you should have about 1_ 1-1/2" pedal travel and the brakes are hard.

 

If you can adjust your brakes to lock wheel or close to drag,when pedal pressed and does,nt return.My guess you have a bad rubber hose or MC piston not returning, and pedal to top may need return spring.

 

Dick Spadaro thanks, I don't bleed the brakes with the drums off, that woudl be rediculous. I took the drums off to make sure all the wheel cylinders were moveing and one wasn't stuck or leaking or making an air leak. I do like that you say to adjust the brake anchors and cams tight prior to bleeding. I ususally do exactly what you explaind but i dont do it with the brakes adjusted tight. I will try this thanks.

 

Sorry, some times I'm a poor teacher. I just assume if you can replace the wheel cyl you should already have the basic knowledge of how to adjust and bleed the system your working on. Thanks for covering that Dick. I do try to help but often don't start at step 1 like a good teacher would. Typing with 2 fingers tend to make as short a conversation as possible.
The Wizzard

 

Yea i know how to bleed brakes. I do it just like he said but of all the brakes i've done I haven't heard of adjusting them up tight prior to bleeding.
the master cylinder should pump them up tight automaticly when you give it pedal pressure. but anything that might help unstress the system i will try. it might take some pressure off of the master cyliner when i first start to bleed them.

the more this conversation goes on the more i'm thinking the master cylinder isn't holding any pressure.

 

Stock MC should have a res ck in it stock. 39-48 WC did not use any sort of push pins etc.,as said ear on shoe. You adjust bottom anchor first then the top till the drum is free to turn ,then do the bottom again then the top again. There is something odd going on here as there is no reason for the WC pistons to retract from the shoe when the pedal is released. Personaly I feel the adjustment is not being done right,there is a very specific way of doing the early 4 adjuster style system.

 

Lets go back to the two push rods coming out of each side of the wheel cylinders. I can't see them in the picture??

Maybe '39 does not have the rods and the shoes are built to insert into the cylinders???

 

The photo is not of his parts, they are mine for example and this system does not use push rods. It's part of the shoe itself.
The Wizzard