CJ5 Brake Problem

1945 - 196*, Willys CJ series, questions, discussions, regarding anything related to the post war jeep.®
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grinnergetter
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CJ5 Brake Problem

Post by grinnergetter » Wed Jul 05, 2017 12:14 pm

I decided that having one front brake operational just wasn't working anymore. I have replaced all 4 wheel cylinders and master cyl. Master has been bench bled. I can bleed the front brakes but cannot get fluid to rear.

When pedal is depressed fluid comes out of distribution block at the front where the line heads back to the rear.

I have blown out the line and it will hold vacuum if I put my bleeder hand pump at the rear. I can hold 25 on the gauge.I can vacuum minimal fluid at the rear. No leaks detected along the frame.

Had my daughter pump and hold pedal and when rear bleeder was loosened the pedal does not go down. Front acts normal, goes to floor.

Now, when I got the Willy's the Master was dry. It had sat for quite a while so the fluid went somewhere over time.

Before I order up more parts I just thought I would run it past those who might have had the problem before. I was thinking about pressurizing the line to be sure it holds air but the vacuum kind of negates the idea....I think.

Glad to hear if anyone has an idea.

Grinner

Chuck W.
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Re: CJ5 Brake Problem

Post by Chuck W. » Thu Jul 06, 2017 8:15 pm

Replace the rubber brake hose between the frame and axle.

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artificer
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Re: CJ5 Brake Problem

Post by artificer » Thu Jul 06, 2017 9:28 pm

Chuck wrote:Replace the rubber brake hose between the frame and axle.
If both rears are exhibiting the problem Chuck is most likely right & on the money.

I see you say there are new rear cylinders so most may not be necessary except Highlighted
BUT
First make sure to hand turn only a drill bit into each of the bleeders to make sure they are free of dirt & that dirt is not blocking the ability to bleed.

Next I would check a few things that will take about 5 minutes & eliminate what is not wrong.
Check the steel lines are not crimped anywhere.

When pressure is in the steel brake line loosen where it fits into the flex line. If pressure is apparent re-tighten
Next loosen @ the out of the flex line. 1. If you have pressure there the flex line is good, so re-tighten. 2. If no, the flex line is bad....replace


If 1. with pressure in the system loosen the steel brake line into each wheel cylinder, in turn, to see if there is pressure there.
Some clowns used to put rivets in brake lines before the wheel cylinder/s to stop leaks rather than fix leaking wheel cylinders.
Possibly because they couldn't get the hub off & didn't know how.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.

grinnergetter
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Re: CJ5 Brake Problem

Post by grinnergetter » Fri Jul 07, 2017 6:54 pm

I gave that line a good hard look and was going to loosen to see if fluid was there but the flare nut is gonna strip. No two ways about it...it's soaking now.

I have not seen one give up on the inside only though so I figured it must be good. I figure air could make it's way past whatever clog might be present but it seems odd that I could pull all that vacuum and hold it.

Friend suggested clamping the front shoes thinking that perhaps the MC does not stroke far enough to engage the fronts and push excess fluid to the rear.

I'll give the line a second try and clamp the fronts to see what happens.

Thanks for the suggestions

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Re: CJ5 Brake Problem

Post by artificer » Fri Jul 07, 2017 8:51 pm

grinnergetter wrote:I have not seen one give up on the inside only though
Quite common on the flex line from the chassis to front axle on MB/GPW, so why not rear, here?
so I figured it must be good
Assuming gets lots of folks into trouble.
I figure air could make it's way past whatever clog might be present but it seems odd that I could pull all that vacuum and hold it. That indicates how good the block [usually a flap of rubber] may be.

Friend suggested clamping the front shoes thinking that perhaps the MC does not stroke far enough to engage the fronts and push excess fluid to the rear.
Don't think so. If the fronts are bled & adjusted properly this action should make no difference.
I'll give the line a second try and clamp the fronts to see what happens.
Very possibly someone clamping the rear hose caused the supposed problem. Using things like vise grips etc. is definitely NOT recommended.
John GIBBINS Member Institute of Automotive Mechanical Engineers [Ret], ASE Master Medium/Heavy Truck & Auto Technician USA -2002 Licensed Motor Mech NSW MVIC 49593 Current 2015
TO DIAGNOSE, TROUBLESHOOT OR FAULT FIND ANY AUTO SYSTEM....
Understand how system parts interact with one another. GOOD parts can then be established & the NOT GOOD problem/s part/s isolated for repair or replacement.


Chuck W.
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Re: CJ5 Brake Problem

Post by Chuck W. » Sat Jul 08, 2017 11:24 am

Again, I'd change the rubber line. $15. from Walck's. If nothing else, it's cheap insurance, but I bet it will fix your problem.

grinnergetter
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Re: CJ5 Brake Problem

Post by grinnergetter » Wed Jul 12, 2017 4:19 pm

You were right..I was wrong..that's all there is to it.

THANKS!!!!

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