General Bendix Treadle Vac Question

[Guest Albert]

I rebuilding Another Treadle Vac i noticed something i did not see when i did the first treadle vac, there is a hole from between the two seals up to the top cover of the master cylinder, so the vacuum should not suck the fluid out of the piston area if the port is open.

[Guest imported_PackardV8]

Albert: That is strictly a weep hole to keep the seals lubed. If the outer most seal of the cylinder and seals at the power unit become weak then it will tend to suck fluid at that point.

Where are u getting kits for the cylinder????

[Guest oldsfiftythree]

1953 olds, ordered rebuild kit from Fusick, It did not include the fiber guide washer. The old one causes the piston to bind as it does not go straight.

Who would have a rebuild kit that would include the fiber washer?

[HH56]

Packard primarily uses Bendix Treadlevac kits from two vendors-- Max Merritt Max Merrit Auto - Packard Parts & Accessories and Kanter Auto 1955 and 1956 PACKARD PARTS Max has a picture of his complete kit on his site (do search in 48-54 for brake rebuild kit). The only fiber washer in piston area I recall is a small thin one in conjunction with the seal items which would not do much to guide the piston. The piston on the Bendix is held by the rod end located in a socket on the power piston on one end and the bore with steel washer and seals etc on the other end. Did Olds use the actual Bendix unit or the GM Moraine version of it.

[Guest RenegadeV8]

On the end of the piston is a large washer. The washer MUST set FORWARD (toward the front of the car) of the compensator port peg that hangs down into the bore of the cylinder.

If the washer sets BEHIND the pin then MAYBE it will cause binding. Otherwise there is nothing else i can think of to cause it to bind.

[Guest oldsfiftythree]

Yes, occasionally when the piston is pushed in and out , the washer at the end of it will be behind the poppet valve stem. What is causing this is that the piston will wobble slightly, enough for the washer to clear the poppet valve stem. The ID of the fiber washer guide is worn and slightly too large causing the piston to wobble. The fiber washer acts as a bearing for the front part of the piston, while the back part is supported by the forward side of the vacuum piston. The shaft diameter is 21/32, the OD of the fiber washer is 1 3/8, and 5/64 thick. I am going to have one made. There are various phenolics, I need one compatible with DOT 3 fluid.

[HH56]

One of the Packard people had the washer go behind the valve and the stem broke off when brakes were applied. There was quite a discussion on one of the other Packard websites about the quality of some compensator valves being supplied. Here is an example of one that was questionable. In the valve on the right, it wasn't sealing properly because the rubber cushion to close the port wasn't deep enough and metal edge could sometimes interfere and prevent a seal. I wonder if possibly your valve came from the same mfg. If there is a quality problem with the rubber quantity aspect, perhaps there is also one with the placement position of the rubber on the shaft. You might have a valve with a different or shorter length stem extending down or one that is marginal.

Edited June 28, 2011 by HH56 (see edit history)

[Guest RenegadeV8]

How high on the firewall does the BTV mount on the 53 Olds?????/

[Guest RenegadeV8]

Once the BTV binding problem is dolbied out and the car is service then BE SURE to check the fluid level in the reservoir of the BTV at least once every 200 - 400 miles for the first 1000 miles.