brake problem

Hi all!! Had a panic stop sat. night going about 50 mph,the back brakes seem to lock up and the rear of the car came right around in a 180(facing traffic),miss the car that pulled out(she came over to apologize,did not see me coming)and nobody was behind me. the car is a 32 glass three window(2600lbs)302 ford with a 5 speed,the front brakes are from a 1956 f1 truck all new parts and the rear are 10.5 ford drum brakes. the master cylinder is a 1963 chevy truck dual set up(brake and clutch),tire are bias ply,road was dry but temps were in the 20s.question is would putting a proportioning valve to the rear brakes help slow the rear from locking up?and can it be put on a car with single master cylinder?. the pedal is hard and the car does not pull side to side. thanks Pete

Yes, you could put an adjustable proportioning valve in the line to the rear brakes to keep them from locking up. The valve would restrict the amount of pressure to the rear brakes, thus giving you a better braking balance front to rear. I use a Wilwood in my car.

Keith

Next time that happens, don't ease off when the rears lock up, slam the pedal harder and the fronts will lock up too. You'll stop quicker and straighter.
The best fix would be bigger front brakes. Get some front drum brakes from a '70-'72 pickup, they're wider.

the adjustable valve, http://www.summitracing.com/parts/WIL-260-11179/ works very well and is an easy install.

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Originally Posted by Weasel Diesel

the adjustable valve, http://www.summitracing.com/parts/WIL-260-11179/ works very well and is an easy install.

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Thanks for the replys!! I got a chance to test a little today(sunday morning and empty school parking lot). back brakes definitely lock up every time so i will try the proportioning valve to the rear brakes,could not get the front brakes to lock up but now i know what to expect i can control the car alot better under hard braking. thanks again Pete

Now don't forget, if your master cylinder is lower than the wheel cylinders, use residual valves. That valve I referred you to earlier works great though. Here's my valve's positioning and setup;

http://img.photobucket.com/albums/v3...ter/brake1.jpg

Here is HOW I did mine :D

http://hotrodders.com/journal_photos...1638161690.jpg

I have the same F-100 front brakes and Ford Bronco 10.5 rear brake setup ... and my car stops GREAT ... with the valve adjusted properly. It takes a little time and a few attemps to get right ... but worth the effort.

Deuce :)

You could change the size of the wheel cylinders---go smaller on rear and then maybe one size bigger on the front

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Originally Posted by jerry clayton

You could change the size of the wheel cylinders---go smaller on rear and then maybe one size bigger on the front

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Jerry, not saying it would not work, but chances are you'd still want the adjustable proportioning valve like Weasel & Deuce show in their photos unless you just happen on the ideal size difference, and he needs the residual valves for sure if the master is low. I'd try the proportioning valve first before spending money on new wheel cylinders. Just my $0.02...

try this thought----a single master cylinder / not late model duels----

a porportioning valve will cut down the total braking from that one very limited source by reducing the force to the rear

Changing the wheel cylinders is cheap, effective and leaves the total brake effort available---if after altering the rear DOWN by 1/8 inch , he wants more front, he can increase fronts by 1/8 inch--probably cheaper than buying a por valve that has 3 possible leak points

Quote:

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Originally Posted by jerry clayton

try this thought----a single master cylinder / not late model duels----

a porportioning valve will cut down the total braking from that one very limited source by reducing the force to the rear

Changing the wheel cylinders is cheap, effective and leaves the total brake effort available---if after altering the rear DOWN by 1/8 inch , he wants more front, he can increase fronts by 1/8 inch--probably cheaper than buying a por valve that has 3 possible leak points

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Yup Jerry, easy and it works.

We had the same problem (but on the opposite end locking up) on our drag race VW which has small front and big rear tires. It's been stopping from 120 mph with drum brakes just fine for the past ten years after the wheel cylinder size change.

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Originally Posted by jerry clayton

try this thought----a single master cylinder / not late model duels----

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In about 1968 or so ... well over 40 years ago ... the feds mandated dual master cylinders on all Cars for a good reason ... SAFETY.

I will not own a single cylinder master cylinder on a street car ... and prefer NOT to have one on a race car.

:D

Way back I had a brand new '79 Mustang with the TRX suspension. It would swap ends on a panic type stop. Ford did everything but change the rear wheel cylinder size - except with new 1" OEMs. They also did a new master cyl, replaced the springs, shocks, loosened the entire suspension - then gave up, saying they had done all that they could and called it a day. They didn't do their own in-house research. The '80s had a 7/8" rear wheel cylinder which I found out accidentally. For about $30 I did them myself, tightened up the suspension to spec and replaced all the rubbers with the original TRX plus called the NHTSA with my complaint. I eventually was reimbursed after a recall was finally issued. Those 1/8" smaller cylinders - did the job :D

Deuce

I think you misread ---the thought to be considered by everybody trying to come up with a fix is that this vehicle has a single master---the dual part is that one side is for clutch and other side for brakes---

And the times that the federal mandated master has saved lives??? more often than not people are driving around with one half there brake system bad, a low pedal, and keep driving--eventually causing a serious mis hap

Nice setup Deuce... What type of line bender do you have to get such crisp tight bends?? My bender has a wide radius ( as you can see).

Here's another plumbing job along with the tools I did it with. Some of the braided flex has since been changed but the brake lines are the same:

http://i70.photobucket.com/albums/i8...DSC_0045-3.jpg

http://i70.photobucket.com/albums/i8...haftloop-1.jpg

http://i70.photobucket.com/albums/i8...ubingtools.jpg

The flare tool is for AN/37* fittings. For any that would have the 45* double flare there is another by Imperial-Eastman which I don't have a photo. There are separate benders for 3/16, 1/4, 5/16 and 3/8

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Originally Posted by Weasel Diesel

Nice setup Deuce... What type of line bender do you have to get such crisp tight bends?? My bender has a wide radius ( as you can see).

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http://www.newmantools.com/imperial/tubebenders_564.gif

I use the Imperial tubing benders. Unfortunately, they are tubing size specific ... so I have one each for 3/16, 1/4, 5/16 and 3/8. I also have a 1/2 for larger tubing. I also have a hydraulic flaring tool.

http://i.ebayimg.com/10/!CBNEcPwCGk~...UGGQ~~0_12.JPG

Mastercool 71475 :D

I like running lines and bought all this stuff just to do my race cars and then street rods. Now ... I do 4 or 5 cars a year for other folks.

:eek:

If you want really tight 90's i use a piece of 1" bar with a deep 3/16" groove in it, Then just pull the tube round it, works perfect.
I have different diameters for tight or loose bends

deuce
do you have the 37* adapter kit for that tool set?? If you do--how well does it work on a/c ss .035 wall tube???

Quote:

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Originally Posted by jerry clayton

deuce
do you have the 37* adapter kit for that tool set?? If you do--how well does it work on a/c ss .035 wall tube???

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No

I have a 37 degree flaring tool that works well.

http://www.aircraftspruce.com/catalo...hics/400-F.jpg

A friend of mine was a aircraft mechanic for one of the major airlines and when he retired ... he gave me his 37 degree flaring tool. I would buy the dies for the Mastercool but my " used ... gifted " unit works so well, I just do not need the Mastercool 37 degree dies :D

I have the ridget like IC2 posted in 37 and works OK, just sometimes need to anneal if it is thicker wall or larger od tube to offset the work hardening--but I was wondering how the hydraulic tool worked in the 37*, so that s why I asked--

Quote:

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Originally Posted by jerry clayton

try this thought----a single master cylinder / not late model duels----

a porportioning valve will cut down the total braking from that one very limited source by reducing the force to the rear

Changing the wheel cylinders is cheap, effective and leaves the total brake effort available---if after altering the rear DOWN by 1/8 inch , he wants more front, he can increase fronts by 1/8 inch--probably cheaper than buying a por valve that has 3 possible leak points

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Hey Jerry!! I like the idea of changing the wheel cylinder sizes!! Here is a stupid question!! How do i order different sizes? Will a NAPA or other auto store have listings for different size wheel cylinder? Thanks for all the input and ideas!! Pete

well the kid behind the counter will want to know the year,make,model,liters,2 or 4 wheel drive anti skid,traction control,2 or 4 wheel abs, etc, etc

You need to find a store that has manufactures cataloques that look like they been opened a few times---when you get a kelsey hayes, etc and go to progressive size charts/listings you will get the data you need---but first you'll need one of yours off for the size and type and match up

good luck

Pete

Denny over at www.dennyshangout.com probably will have the info you need---He has more info than the Smithsonion Institute. Tell him I sent you

Jerry

Quote:

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Originally Posted by jerry clayton

Denny over at www.dennyshangout.com probably will have the info you need---He has more info than the Smithsonion Institute. Tell him I sent you

Jerry

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So true, so true, I knew he was older than dirt.:LOL::LOL::LOL::LOL::D

Not to keep beating a dead horse here but I was going back over this thread and realized that I didn't mention a couple of very basic things----

WHEN you have a braking problem, the problem is probably on the opposite end of the car not doing its share of the load---in this case ( and many especially with big and littles) the front brakes aren't doing there share of the stopping--and the rears then lock up early---

In drum brakes this can be as simple as having the shoes on backwards or the backingplates on the wrong side---there is a primary shoe and seconary shoe---they go on a certain way--and since drum brakes are self energising the side of the car the backing plate on might make a differance.

Quote:

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Originally Posted by jerry clayton

Not to keep beating a dead horse here but I was going back over this thread and realized that I didn't mention a couple of very basic things----

WHEN you have a braking problem, the problem is probably on the opposite end of the car not doing its share of the load---in this case ( and many especially with big and littles) the front brakes aren't doing there share of the stopping--and the rears then lock up early---

In drum brakes this can be as simple as having the shoes on backwards or the backingplates on the wrong side---there is a primary shoe and seconary shoe---they go on a certain way--and since drum brakes are self energising the side of the car the backing plate on might make a differance.

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....with the long shoe always (well, usually) going on the back side:eek:

If you can measure the diameter of your rear wheel cylinders, and reduce the size 1/16"
it will probably eliminate the lock up situation, assuming the brakes are all adjusted correctly. If 1/16" is not enough go to the next smaller size. Wheel cylinders are cheap and is the best way to balance the brake system. Proportioning valves take away brake force, not the most desirable situation in a panic stop. Here are some popular sizes and Wagner part numbers for Ford 8" & 9" rear ends, for both the right and left sides.
7/8"- WC 17507/8, 29/32"- WC 28804/5, 15/16"- WC 17509/10, or WC 59240/1, 31/32" WC 49234/5, 1"- WC 78974/5. If your parts store doesn't have Wagner have them cross these numbers over to the brand that they carry
HemiDeuce..

Quote:

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Originally Posted by HemiDeuce

If you can measure the diameter of your rear wheel cylinders, and reduce the size 1/16"
it will probably eliminate the lock up situation, assuming the brakes are all adjusted correctly. If 1/16" is not enough go to the next smaller size. Wheel cylinders are cheap and is the best way to balance the brake system. Proportioning valves take away brake force, not the most desirable situation in a panic stop. Here are some popular sizes and Wagner part numbers for Ford 8" & 9" rear ends, for both the right and left sides.
7/8"- WC 17507/8, 29/32"- WC 28804/5, 15/16"- WC 17509/10, or WC 59240/1, 31/32" WC 49234/5, 1"- WC 78974/5. If your parts store doesn't have Wagner have them cross these numbers over to the brand that they carry
HemiDeuce..

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Wow!! Thanks!! You saved me alot of leg work!! Thanks to all for your feedback, this forum really makes building a car easier!!! Wealth of Knowledge!!
Pete

two pages of pictures and opinions, whew, yes it will work

FWIW Internationals have same system, parallel mastercyl, brake/clutch and a single line supplying all four corners for the brakes, just a 'tee' below the master cyl for front/rear distribution.

Quote:

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Originally Posted by Weasel Diesel

Now don't forget, if your master cylinder is lower than the wheel cylinders, use residual valves. That valve I referred you to earlier works great though. Here's my valve's positioning and setup;

http://img.photobucket.com/albums/v3...ter/brake1.jpg

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What do the residual valves do to the system as my brakes on the 32 feel like they have air in the system but they don't

Quote:

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Originally Posted by roadster

What do the residual valves do to the system as my brakes on the 32 feel like they have air in the system but they don't

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They stop bleed back.