Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 05-05-2021, 08:10 PM   #1
Pdgx
Member
 
Pdgx's Avatar
 
Join Date: Sep 2013
Location: Central Florida
Posts: 56
Default Hydraulic brake balancing

Has anyone had problems balancing brakes on hydraulic conversions (46-48 backing plates) ?
Brakes have been re-bled with no air found; mechanically adjusted each brake to just before drag - but it’s repeatedly pulling left, with only the left front with decent braking effort. Any further tightening of right side brakes causes lockup while adjusting.
It appears the left front (with the shortest hydraulic line) is getting activated first, and the others are not catching up. Hard stopping on gravel, locks the left front only.
(Are there any restrictors in the hydraulics, like modern vehicles, to make up for the difference in hydraulic line length ?)
There are less than 100 mi on this restoration when the hydraulics were added.
Missing something here .....

Thx
Pdgx is offline   Reply With Quote
Old 05-05-2021, 08:47 PM   #2
Pete
Senior Member
 
Pete's Avatar
 
Join Date: May 2010
Location: Wa.
Posts: 5,374
Default Re: Hydraulic brake balancing

It could be several things.
Try looking at the right wheel cylinder. Check inside for free movement of pistons. Check that shoes move freely on the pivots. Check for pinched or kinked line somewhere from the left to right front. Check hose for obstruction.
You should need NO proportioning valves or restrictions in that system.
You should be using 1/4 inch STEEL tubing for lines.
Pete is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 05-05-2021, 09:55 PM   #3
Bob C
Senior Member
 
Join Date: May 2010
Location: So Cal
Posts: 8,712
Default Re: Hydraulic brake balancing

Did you get the primary and secondary shoes in the right location on both sides??
Bob C is offline   Reply With Quote
Old 05-05-2021, 10:25 PM   #4
CWPASADENA
Senior Member
 
CWPASADENA's Avatar
 
Join Date: May 2010
Location: PASADENA, CA
Posts: 1,881
Default Re: Hydraulic brake balancing

The hydraulic lines are large enough that the extra line length to the R/H wheel cylinder should not make any difference at all. With everything adjusted and completely bled, there is actually very little displacement of fluid when the brakes are activated.

You have some other problem than the extra length of line to the R/F. Restriction in a line, fitting or hose. Wheel cylinder sticking, lining contaminated, shoes not properly arced to the drums or a problem with the assembly of the shoes.

Chris W.

Last edited by CWPASADENA; 05-05-2021 at 10:26 PM. Reason: TYPO
CWPASADENA is offline   Reply With Quote
Old 05-06-2021, 05:58 AM   #5
Patrick L.
Senior Member
 
Patrick L.'s Avatar
 
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
Default Re: Hydraulic brake balancing

In addition, it may be a bad/collapsing flex line. Have you tried backing off the left side ?
Patrick L. is offline   Reply With Quote
Old 05-06-2021, 07:44 AM   #6
nkaminar
Senior Member
 
nkaminar's Avatar
 
Join Date: Jan 2012
Location: Western North Carolina
Posts: 3,819
Default Re: Hydraulic brake balancing

Sponsored Links (Register now to hide all advertisements)
I am afraid that I agree with the others that there is something wrong with the braking system, not just the adjustments. If you are not competent to analyze the problem and fix it then take the car to a good brake shop.

There is no effect in the length of the hydraulic lines.
__________________
A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
nkaminar is offline   Reply With Quote
Old 05-06-2021, 07:50 AM   #7
nkaminar
Senior Member
 
nkaminar's Avatar
 
Join Date: Jan 2012
Location: Western North Carolina
Posts: 3,819
Default Re: Hydraulic brake balancing

One other thought: There are three adjustments for the brake shoes in hydraulic systems. There is the adjustment at the stationary ends of the shoes, but also the ones at the centers of the shoes. If you just adjusted the one at the ends of the shoes then you will get uneven braking. I ran into the uneven braking problem with my converted coupe until I figured this out.
__________________
A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
nkaminar is offline   Reply With Quote
Old 05-06-2021, 03:08 PM   #8
Charlie Stephens
Senior Member
 
Join Date: May 2010
Location: Southern California
Posts: 7,017
Default Re: Hydraulic brake balancing

Are all of the shoes the same? Bought at one time from the same place and look identical?

Charlie Stephens
Charlie Stephens is online now   Reply With Quote
Old 05-06-2021, 04:56 PM   #9
daveymc29
Senior Member
 
daveymc29's Avatar
 
Join Date: Sep 2010
Location: Danville, CA
Posts: 1,550
Default Re: Hydraulic brake balancing

I had some wheel cylinders that had the drilled passage bringing fluid into the cylinder about 3/16 inch down the bore from the base of the cylinder, maybe even farther. This cylinder didn't want to actuate the piston when the brakes were applied, I dropped a bit of plastic into the cylinder before putting the piston in. That cured the problem while I searched for cylinders that were drilled properly.

Last edited by daveymc29; 05-06-2021 at 10:21 PM.
daveymc29 is offline   Reply With Quote
Old 05-06-2021, 09:03 PM   #10
Kurt in NJ
Senior Member
 
Kurt in NJ's Avatar
 
Join Date: May 2010
Location: on the Littlefield
Posts: 6,140
Default Re: Hydraulic brake balancing

Had a 39,and 46, when I had such problems it was from wheel cylinder leaking onto linings, after years of having to work on one car or the other for brake problems and failures I solved the problem--- sold those cars, now have a 36, and model A because they have reliable mechanical brakes , had the A almost 50 years, figure next year I should go through then and clean, lubricate and correct what I didn't know what to do exactly as a 15 year old
Kurt in NJ is offline   Reply With Quote
Old 05-07-2021, 09:10 AM   #11
Model A Ron
Senior Member
 
Model A Ron's Avatar
 
Join Date: Feb 2021
Location: Troutman, NC
Posts: 717
Default Re: Hydraulic brake balancing

I am not sure why you would need hydraulic brakes on a Model A. My mechanical brakes are adjusted properly and I can lock them up whenever I like.
Model A Ron is offline   Reply With Quote
Old 05-07-2021, 09:53 AM   #12
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,011
Default Re: Hydraulic brake balancing

Quote:
Check hose for obstruction.
Quote:
Restriction in a line, fitting or hose.
Quote:
it may be a bad/collapsing flex line.
Ditto
__________________
If you don't hear a rumor by 10 AM, start one!.
Got my education out behind the barn!
katy is offline   Reply With Quote
Old 05-07-2021, 10:35 AM   #13
Bruce Newbery
Member
 
Join Date: May 2010
Location: Williams Lake B.C. Canada
Posts: 49
Default Re: Hydraulic brake balancing

I had severe problems with my hydraulic brakes aa well. I have a brake booster on mine and the car would dive to the Center of the road. I am using DOT 5 brake fluid. I tried adjusting heavy to the passenger side and nothing worked. I noticed a dampness on the left front wheel cylinder. I removed the new leaking wheel cylinder and found porosity in the bore. Most of these wheel cylinders are made in China and they are junk. I measured the cylinder bores and it was not within specs I went hunting for made in U S. A ones and no luck. I found that Raybestos cylinders are made in China but they have quality control. I put the new wheel cylinder in ,no leaks the car still dived. I removed the brake shoes and steam cleaned them ,brake-cleaned them and the car was better but not perfect. I went to a old timer that owned a brake and muffler shop and he said throw the brake shoe away and put a new one in. He said you will never get the brake fluid out of the lining. I did what he said and it cured the problem. These hydraulic brakes can be a problem but once you figure it out, they are really good. My car pulls straight on a panic stop and It will lock all four tires . Also when you buy a new wheel cylinder, take it apart and inspect it and measure it.
Bruce Newbery is offline   Reply With Quote
Old 05-07-2021, 10:45 AM   #14
Model A Ron
Senior Member
 
Model A Ron's Avatar
 
Join Date: Feb 2021
Location: Troutman, NC
Posts: 717
Default Re: Hydraulic brake balancing

Quote:
Originally Posted by Bruce Newbery View Post
I had severe problems with my hydraulic brakes aa well. I have a brake booster on mine and the car would dive to the Center of the road. I am using DOT 5 brake fluid. I tried adjusting heavy to the passenger side and nothing worked. I noticed a dampness on the left front wheel cylinder. I removed the new leaking wheel cylinder and found porosity in the bore. Most of these wheel cylinders are made in China and they are junk. I measured the cylinder bores and it was not within specs I went hunting for made in U S. A ones and no luck. I found that Raybestos cylinders are made in China but they have quality control. I put the new wheel cylinder in ,no leaks the car still dived. I removed the brake shoes and steam cleaned them ,brake-cleaned them and the car was better but not perfect. I went to a old timer that owned a brake and muffler shop and he said throw the brake shoe away and put a new one in. He said you will never get the brake fluid out of the lining. I did what he said and it cured the problem. These hydraulic brakes can be a problem but once you figure it out, they are really good. My car pulls straight on a panic stop and It will lock all four tires . Also when you buy a new wheel cylinder, take it apart and inspect it and measure it.
I have heard many stories like yours. As for made in China stuff I work in manufacturing and I have seen nothing but issues with China metal. If the part is not structural it may be fine but if you need it to perform forget about it. The Metallurgy tells the story when you look at the chemistry and micro structure of the metal. I have come to the conclusion that ASTM Standards are optional in China.

Ron
Model A Ron is offline   Reply With Quote
Old 05-07-2021, 10:49 AM   #15
Bruce Newbery
Member
 
Join Date: May 2010
Location: Williams Lake B.C. Canada
Posts: 49
Default Re: Hydraulic brake balancing

I had severe problems with my hydraulic brakes aa well. I have a brake booster on mine and the car would dive to the Center of the road. I am using DOT 5 brake fluid. I tried adjusting heavy to the passenger side and nothing worked. I noticed a dampness on the left front wheel cylinder. I removed the new leaking wheel cylinder and found porosity in the bore. Most of these wheel cylinders are made in China and they are junk. I measured the cylinder bores and it was not within specs I went hunting for made in U S. A ones and no luck. I found that Raybestos cylinders are made in China but they have quality control. I put the new wheel cylinder in ,no leaks the car still dived. I removed the brake shoes and steam cleaned them ,brake-cleaned them and the car was better but not perfect. I went to a old timer that owned a brake and muffler shop and he said throw the brake shoe away and put a new one in. He said you will never get the brake fluid out of the lining. I did what he said and it cured the problem. These hydraulic brakes can be a problem but once you figure it out, they are really good. My car pulls straight on a panic stop and It will lock all four tires . Also when you buy a new wheel cylinder, take it apart and inspect it and measure it.
Bruce Newbery is offline   Reply With Quote
Old 05-07-2021, 11:11 AM   #16
jimvette59
Senior Member
 
jimvette59's Avatar
 
Join Date: Jun 2010
Location: Perry OH
Posts: 1,327
Default Re: Hydraulic brake balancing

Brake fluid on the lineings.
jimvette59 is offline   Reply With Quote
Old 05-07-2021, 01:29 PM   #17
Patrick L.
Senior Member
 
Patrick L.'s Avatar
 
Join Date: May 2010
Location: Largo Florida
Posts: 7,225
Default Re: Hydraulic brake balancing

Any progress yet ?

I was thinking these were center-plain, they're not.

So, check that shoes are installed correctly. These have primary and secondary shoes. Primaries are short, secondaries long. Primaries go toward the front, secondaries rear. I've always been surprised at many times they are installed incorrectly, happens a lot.

As mentioned, check shoes for contamination. It that happened replace them. Why were they contaminated in the first place ?

Make sure they are adjusted correctly.

If all this is correct, a flex hose could still be collapsing. Doesn't happen often, but, it does.
Patrick L. is offline   Reply With Quote
Old 05-07-2021, 04:01 PM   #18
Pdgx
Member
 
Pdgx's Avatar
 
Join Date: Sep 2013
Location: Central Florida
Posts: 56
Default Re: Hydraulic brake balancing

Quote:
Originally Posted by jimvette59 View Post
Brake fluid on the lineings.
Thanks for all the feedback.

Not sure what ‘good brake shop’ suggested adjusting the stationary and the middle adjusters, but ‘46-48’s only have middle adjusters.

Did find a little (DOT5) fluid on the right front, so after this weekends show, looks like I’ll pull all the drums and check the cylinders for leaks.

Thx

Last edited by Pdgx; 05-09-2021 at 07:59 AM.
Pdgx is offline   Reply With Quote
Old 05-07-2021, 04:17 PM   #19
nkaminar
Senior Member
 
nkaminar's Avatar
 
Join Date: Jan 2012
Location: Western North Carolina
Posts: 3,819
Default Re: Hydraulic brake balancing

I stand corrected. My brakes must have been a different year as they had the little star wheel at the bottom. Or, that was maybe 55 years ago, so the brain cells that held that information may be gone.

Pdgx, please post your fix when done so that we may all learn.
__________________
A is for apple, green as the sky.
Step on the gas, for tomorrow I die.
Forget the brakes, they really don't work.
The clutch always sticks, and starts with a jerk.
My car grows red hair, and flies through the air.
Driving's a blast, a blast from the past.
nkaminar is offline   Reply With Quote
Old 05-07-2021, 07:57 PM   #20
Jim Cates
Junior Member
 
Join Date: Jul 2010
Posts: 8
Default Re: Hydraulic brake balancing

The problem I had was: My master cylinder did not have a check valve.
Drum brakes should hold 10 pounds of pressure in the lines.
Jim Cates is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 02:17 PM.