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1929 Chrysler 77 wheel cylinders


Jerzjer

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Can anyone tell me if the front and rear brake cylinders are the same on this car. I have the front ones off and want to order all four of them but I am waiting for a tool I ordered from Amazon to pull the rear drums. Also where is the best place to get the wheel cylinders. Numbers look like 9935 U

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DJA8 and DJA9 Thanks I thought they were . The bolt holes on the front to bolt to the backing plate are 1.5 inches apart and the rear are 1.75 inches center to center I was able to measure the back ones from the outside of the backing plate. 

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The front and backs are different bores based on the Wagner book I have. Also. looking a you picture it appears they have been brass sleeved. If so, they should be rebuild-able  with just new cups.

 

Chrysler 77.jpg

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Standard galvanic corrosion is going on in the cylinder shown above. You have an aluminium piston in a brass tube. The Al is at the top of the galvanic series, brass is about half way down. The Al corrodes in the presence of an electrolyte (moisture in the brake fluid). Just clean it up and reassemble with rubber grease. If the car will sit for a while (months or years) before you use it, this may happen again before you use it.

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"Seals"? There are cups inside the pistons. If they have sharp edges on the top, they are good to use. If there is ANY damage or rounding or loss of sharp edge on those cups, replace. They are dirt cheap so get some in anyway. The covers that the shoes or their actuators go through to contact the piston should be undamaged too.

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After having a few brass sleeved cylinders freeze up the aluminum pistons, I use a coating of EIS brake assembly lube on all cleaned cylinder bores, pistons, and rubber cups. That ended the corrosion and frozen piston problems, like you have.

 

Paul

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1 hour ago, PFitz said:

After having a few brass sleeved cylinders freeze up the aluminum pistons, I use a coating of EIS brake assembly lube on all cleaned cylinder bores, pistons, and rubber cups. That ended the corrosion and frozen piston problems, like you have.

 

Paul

Can you show this please? I have been unable to find anything called anything like brake assembly lubricant here. I have been using rubber grease, unsuccessfully.

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2 hours ago, Spinneyhill said:

Can you show this please? I have been unable to find anything called anything like brake assembly lubricant here. I have been using rubber grease, unsuccessfully.

EIS brand is just one of many brake system assembly lubes available here in the USA.   I don't know if the other brands are as good at preventing aluminum from reacting with brass sleeves. 

 

It's different from brake grease. It's a liquid lubricant that come in a squirt bottle because it is more like the viscosity  of motor oil, but unlike motor oil, it's compatible with all DOT brake fluids. 

 

Paul

Edited by PFitz (see edit history)
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Just searched and I can't find a listing for the EIS brand, either.  A bottle lasts for many brake jobs and it's been some years since I bought one at my local autoparts store.  Might be that it's been discontinued by now ????  

 

From what I've read online, the Raybestos BAF12  brake assembly lube may work the same.  https://www.summitracing.com/parts/agb-baf12

 

Paul

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If you want to have your brake cylinders done the right way and are in the U.S., sent them to "Karp's" brake service in California.

They use 304 stainless tubing to sleeve the cylinders and master if required.

I had my '40 Buick LTD done 6 years ago and she has not leaked a drop, and she'll still stop on a dime !

 

Mike in Colorado

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