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1947 Buick 56C pull hard to right


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Hello All, I have a 47 Buick Super Convertible that just came back from the body/paint shop. When it left (6 months ago) it braked normal. Now that it’s back it pulls very hard to the right when braking. The right front wheel locks up and shifts the wheel to the rear of the car.  I have checked the operation of all the usual suspects including removing the wheels/hubs, inspecting for bake shoes hanging up on backing plates, disassembling of wheel cylinder for inspection, bleeding the brakes, & checked all suspension bolts and backing plate bolts. I also filled the shocks with fluid ( right side was very low). All king pins and steering components are tight. There is a slight leak out of the back of the Master Cylinder. Under the M/C there is a metal cylinder with a place to connect an electrical wire. There is no wire on it. There is also a junction block with a pressure switch which I assume is for the brake lights. Can anyone shed light on anything I may have overlooked? One thing to note is that the Body shop had to put the car on the frame machine and move the right rail 1/2” to the left in order to align the fenders properly. 
 

Help and Thanks in advance!

 

Ken

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Flexible brake lines go bad from the inside out, and develop an internal "flap" which lets brake fluid go toward the cylinder when braking, but doesn't let it flow back.  Ask me how I know.  If the flex brake lines haven't been replaced in the last ten years, do it on General Principles even if that's not the cause of the current malfunction.

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Usually those symptoms are caused by oil or brake fluid on the shoes. But I assume you have checked that, so sticky wheel cylinder or above mentioned hose problems are your next "stop"

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Thanks for the comments. I have not checked the alignment yet. I’ll see if we have time to do that today and get back with y’all. I will also disassemble the left front wheel cylinder and inspect for sticking piston or excessive wear. I had excellent fluid flow when bleeding. Apparently there isn’t supposed to be a proportioning valve on this model. The repair manual doesn’t mention one.

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6 hours ago, KNG54 said:

I had excellent fluid flow when bleeding.

Still could be a stuck piston.

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I ordered new wheel cylinders and front hoses today. I’m also replacing the M/C bc it has a minor leak past the rear seal into boot. I’ll post the results after Easter. I’m away from the car until then.

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17 hours ago, KNG54 said:

Thanks for the comments. I have not checked the alignment yet. I’ll see if we have time to do that today and get back with y’all. I will also disassemble the left front wheel cylinder and inspect for sticking piston or excessive wear. I had excellent fluid flow when bleeding. Apparently there isn’t supposed to be a proportioning valve on this model. The repair manual doesn’t mention one.

Proportioning on these old cars is done by using smaller cylinders on the rear wheels than the front. Gives the front the most braking. 

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