Treadlevac

Unknown

Opinions solicited: Just acquired a '57 Hudson with the power brake Treadlevac unit and it was rebuilt by a reputable rebuilder in '99. Problem is the brakes will throw you forward (stop on a dime, as they say) the first 5 or 6 times and then as you drive along and start braking, they seem ok. But coming to a full stop they fade way down to the floorboard. The car would barely hold a small hill with me standing on the pedal. Do not yet know that status of the brake shoes, but the master cylinder is full and fluid clean wiht no leaks on any wheel cylinders. On the return from the short drive, I really had to ride the brakes to pull the car in the garage. Cannot dicscern any vacuum leaks. We thought we had found the problem in a pinched vacuum hose at the T/V unit, but we replaced the hose and no longer have akink in the line. That obviuosly did little if anything to correct the problem. Any ideas?

Unknown

I just rebuilt the TV system on my '54. If you'd like to email me directly perhaps we could hook up on the phone and I can share with you some of the things I learned that may help you.

Hudsonly,

Hal Souers
thsouersHET@aol.com leave HET out of the address.

EssexAdv

Make sure the one way valve is working on the vac. feed into the vac can. If it is, send the TV unit back to the rebuilder and have him FIX it.

Unknown

Sounds like classic master cylinder leakdown rather than a power boost problem.

Unknown

Test drive today confirmed it's not air in the system. And just to see what would happen vacuum wise if I shut it down, sat for a moment and restarted, nothing there either. Strange behaviour though. Good brakes initially and even if driving along after awhile, the brakes will certainly catch and slow the car down as normal....it's just the last little phase of stopping. So, we're going to tear it all down later in the week and see what the culprit is. Anyone know if Dave Konstansek has email now?

Unknown

Paul, I thought the freeplay on the '57 brake pedal was too great, so I crawled underneath and adjusted the long rod and now have about 1/4" freeplay. No test run yet due to rain in the area.

Couple of questions:

1. Does the T/V indeed mount under the car such that the reservoir is tilted forward?

2. The exists a long rod type device that looks like it is meant to guide a cable or something and it extends just up to a hole in the frame but not through it. If it extn=ended through, it would contact the brake rod. Any idea what that is id you know what I am referring to?

Unknown

Test drive tonight, brakes continue to diminish after the car is driven a mile or two and 15-20 applications of the brake pedal. We shut the engine down and tried the brakes and the mechanical seem fine. We got back to the garage and pulled the valve that is located JUST at the manifold vacuum intake and found a rubbery gooey substance in the valve. We pulled it out. It appeared to hav ebeen tapered at one time but now just a 1/2" long piece of spongy rubber with no kind of spring(s) in sight. For now we have replaced the valve piece but now it is just a straight flow-thru. Initial application of the brakes cause the engine to idle up just for a second but not significantly. Will try to test drive tomorrow evening or over the weekend. Hopefull this will cure the brake problem. Easy thing to overlook. I'm real curious WHY any kind of rubber type valve would have been located where there is engine heat.

Unknown

BRAKE SYSTEM UPDATE! We discovered that the manifold vacuum source valve was not the problem with hill creep. We STILL have hill creep. We replaced all four wheel cylinders, all 4 wheels brake shoes, all rubber hoses, and new lines AND had the Treadlevac rebuilt. The brakes will stop you anytime on a dime, but try to hold the car on a hill with the brake pedal depressed and after 5-10 seonds the car will creep forward downhill without any change in the brake pedal. I am totally out of ideas!

Unknown

Hi,---My 54 Hornet with power brakes does the same thing, but momentarily releasing the brake pressure & immediately reapplying the brake gives me a new time frame before the creep begins again.

Unknown

That is a good data point. Have to check and see if there were any '54 or later service bulletins that might have covered the subject.

Unknown

I did one more thing in that I pulled the floor-mounted air filter off and tried to examine it as best I could. It is a sealed unit with some sort of coarse steel wool type filtering material in it. Unable to disassemble it, I tested it by blowing compressed air through it and it flowed both directions. I reinstalled the filter on the car and replaced the hose clamp with one a size smaller and tightened it down good.

I took a test drive with the purpose being to turn the engine off on a hill and see how well the mechanical-only brakes would hold, initially before the car was driven far and warmed up and then after a drive. Initially the brakes held just fine with no creep down the hill whatsoever. I proceeded then to drive further and with more brake applications than anytime previously. I repeatedly stopped on hills and held the brake pedal down and the car never creeped forward this time. I might mention, too, that, I have the idle on the car set up to about 700-750 RPM which would create a tendency for the car to move forward. Since on this outing the car never creeped forward with power on, I did not bother to test it without the car running.

In summary, the only thing that was “different” in this last test drive was the pulling off of the air cleaner, blowing compressed air through it and replacing the hose clamp. Perhaps the hose clamp, but it is doubtful. But now I ponder this input I received on the forum “I'm also assuming that since you've replaced all the shoes, you've done a sufficient number of stops to "seat" the linings to the drums.” Now this could very well explain the problem relative to a new brake system, but how does it explain the problem occurrence with the old brake shoes?

Unknown

Last posting by RO; forgot to login.