1950 brake locks up

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packardinhawaii
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Joined: Mon Jan 07, 2013 10:41 am

1950 brake locks up

Post by packardinhawaii » Mon Jan 07, 2013 11:02 am

I just got a 1950 standard eight club coupe and the front driver side brake locks up. The previous owner rebuilt the brakes. currently we took off both front wheels. The brake pads are set up differently, referring to maintenance manual there is no information on which pad goes in front (only says the front shoe is primary and the back shoe is secondary). Our mechanic says that he worked on a 80's dodge truck and that the drums had the short shoe in the back and that was the cause. It also looked like there was some grease glazed on the pad.
Thanks, Ed

Dave Czirr
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Re: 1950 brake locks up

Post by Dave Czirr » Mon Jan 07, 2013 1:09 pm

Just to get the part names right, "pads" are the friction surfaces for disc brakes; for drum brakes the assembly with the friction lining is a "shoe". The shoe with the shorter lining is the primary shoe and goes forward, and if the two return springs have different strengths, the weaker spring goes on the forward (primary) shoe. Thus when the brakes are applied the forward shoe contacts the drum first and this action multiplies the brake effort by "caming" the rear shoe against the drum with extra force. Grease or brake fluid-soaked linings will never give proper brake action and should be discarded and replaced after fixing whatever leaked onto them, and to keep proper brake equalization left to right, you should replace all the front shoes both left and right unless you're fortunate enough to be able to get exactly the same lining material that was on the damaged shoes. If indeed it was grease that leaked, replacing front grease seals is a very easy job and also gives you the opportunity to remove, clean, inspect and repack the inner wheel bearing. Sounds like the former owner wasn't much of a mechanic, inspecting the grease seals is a part of any quality brake job. But all this said, a brake locking up is more likely from brake fluid leaking onto the linings rather than grease which suggests you best check behind the wheel cylinder dust cups to see if it is dry, otherwise you'll just ruin the next set of shoes as well.

packardinhawaii
Posts: 7
Joined: Mon Jan 07, 2013 10:41 am

Re: 1950 brake locks up

Post by packardinhawaii » Mon Jan 07, 2013 4:41 pm

Thank you for the quick reply. I am more used to the new cars as this is my first classic so I tend to mix up the terms. We think that the grease that got on the shoe was from accidentally touching it during the reconstruction (we got grease on it because of this method then cleaned it off).

The previous owner was going to hotrod it, but his wife didn't let him.

Looking at the shoe it does have black stains on it. where as the other shoes are clean

Adam
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Location: lincolnshire, uk

Re: 1950 brake locks up

Post by Adam » Tue Jan 08, 2013 5:52 am

Welcome to the forum!!

If the grease stains that you have are simply from dirty finger marks, and the linings are otherwise new, then I would clean them off with brake cleaner (a proprietory solvent cleaner) and use them, but if they are old or mismatched, or heavily soaked, do as Dave suggests and replace them with known good linings. I suspect that your brake out-of-balance problem is more likely to be caused by seized wheel cylinders or poor adjustment, from the previous owners efforts. Your brake system is essential to safety, for obvious reasons, so please ensure, for your own safety and the good reputation of the hobby, that they are in excellent condition.

Brakes on 48 to 50 cars have been discussed on this forum quite a lot, so do some background reading here and then do it correctly. It is so much more satisfying when you do.

Just one more thing I am passionate about, before I get down from my soapbox; please, please rebuild or renew the brake master cylinder as part of your project. There is no diagonal split system on your Packard and M/cyl failure means NO BRAKES whatsoever!!!!! The action of bleeding brakes means moving the m/cyl seal over parts of the bore that it has not been over for years and it often starts to leak. Please rebuild it before that can happen. You will be rewarded by a much better brake pedal anyway.

Please do keep us informed of your progress. There is lots of free advice and huge experience on tap on this forum.

Adam..
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

packardinhawaii
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Joined: Mon Jan 07, 2013 10:41 am

Re: 1950 brake locks up

Post by packardinhawaii » Tue Jan 08, 2013 8:31 am

It is always handy to have working brakes so I will do that because I intend to drive this car. This is actually a nearly running car the rest of the work is just rebuilding the parts that were damaged by ethanol (carb, fuel pump).

Adam
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Location: lincolnshire, uk

Re: 1950 brake locks up

Post by Adam » Wed Jan 09, 2013 1:22 am

That`s great. I always think you need to drive a car as part of getting it sorted out. It is much more fun than being mired in a lengthy rebuild, at least until you are really hooked !!

Is your ethanol fuel really that damaging? We have a 5% ethanol content in petrol here in the UK, with standards being drawn up for E10 (10% content). What content do you have in Hawaii? So far the 5% stuff has not caused me any noticeable effects on my old cars.

In any case. it will be beneficial to freshen up the pump and carb with a rebuild. I think the modern diaphragms are fine with the fuel.

Any chance of posting some pics of your car? Thay are always popular.

Adam..
"Do not underestimate the English cousin.....they are not as stupid as they look!" - Signor Altabani in The Italian Job.

packardinhawaii
Posts: 7
Joined: Mon Jan 07, 2013 10:41 am

Re: 1950 brake locks up

Post by packardinhawaii » Tue Jan 15, 2013 9:11 pm

sorry to get off topic, but I got the carburetor and the fuel pump back and at least the carb is ethanol safe. Should be running by the end of the month. I have never really noticed the ethanol content of the gas here but I do remember E85 gasoline that was here for a while. I think that we generally have higher ethanol content because it is subsidized, the ethanol free gas is twenty cents a gallon more :( . The next time I'm out I'll check the ethanol content and report back.

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