Hi, all...

Rebuilding my F2 (F3, F4, etc) Master Cylinder. In the rebuild kit, there's a rubber "O" ring, about 1/8" thick, pretty wide, that I can't remember taking out, although I have one in the parts I took apart, and would like it to go where it belongs!! Mine has a brass or copper washer in the middle, although I don't know if that was there, or just managed to get there on it's own. It's about 1" OD, 1/2" ID.

Perhaps it goes just before the large washer then the keeper?

Help!!

Thanks in advance...

R

 

Roger,

I hope this helps:

 

Bob - not really, it just doesn't seem to show the piece I am talking about - I know it came OUT of this master cylinder, and the repair kit had one to put back in, but I'm just not sure what it is, and where it went.

I'll try to take a picture tomorrow, and see if anyone recognizes it.

R

 

Here's the probable answer.

The 1948/56 Ford Truck Parts Catalog calls for B9J-2004-A for the M/C rebuild kit, which fits 1948/56: F2 (F250), F3 (F350), F5 (F500), F6 (F600) etc.

B9J-2004-A replaced the (1948/56) part number of: BPA-2004-A. I compared the two kits; BPA-2004-A consisted of 7 parts, B9J-2004-A has 8 parts.

** B9J-2004-A also fits 1957/75 P350/500 = Parcel Delivery, so there's one extra part in the kit for use in the P Series only.

The P Series uses a different master, but the internal parts are the same...except for that one additional part.

I know what you're going to say..."I didn't buy the Ford kit."

But, since the Ford kit fits more than just 1948/56's, I would think the aftermarket kit would too.

 

Roger

Is it more flat than like an o-ring? More like a thick flat disc with a hole in it. The o/d about the size of the cylinder bore? If so it is the first thing that goes back in and lays right against the frone of the cylinder bore. It is easy to miss it when taking it apart and then it falls out later and you don't know where it came from.
Hope this helps.
Richard

 

that o-ring goes in first!! then valve, spring, cup, piston,etc.

 

Is the O ring shown in the diagram I posted? Is so what part number?

 

The original 1948/56 Ford kit consisted of:

91A-2151 .. Gasket

91A-2152 .. Gasket

91T-2169 .. Piston Assy.

91T-2173 .. Cup

91A-2174 .. Snap Ring

AOA-2178-A .. Valve Kit

91A-2180-B .. Boot

The B9J-2004-A kit adds what Ford calls a "seat."

No part number is given.

Where's this so called large O-Ring fit? It's not even shown in the above (middle) illustration, nor did it come with the original kit.

EDIT: Could someone be refering to #2188 (shown above?). It didn't come with the original kit. It's: 91T-2188, which Ford calls a "Brake Master Cylinder Piston Stop Plate."

 

Bob

In the top picture it looks like the o-ring might be part of 2178 but I think 2178 is a check valve and the o-ring goes in before it does. The check valve seals against it. With out descriptions of the illustrated parts it is tough to be sure. Not sure the o-ring is pictured.

Richard

 

I was posting at the same time as Number Dummy. After reading his post it is possible that the flat O-ring is the seat mentioned and was not used in 48/56. The cylinder could have been rebuilt at some time and that part added then. It would not cause any problems by having it in there but may not have been in there originally.

Just a guess

Richard

 

no part number, eliminates valve hitting end of cylinder. when installed, make sure piston has full travel. you should be able to see this through port holes inside master. if piston bottoms out, remove o-ring

 

Post #8

I just listed the part numbers and the descriptions for what came in the original kit. I also listed the part number and description for #2188.

If y'all want the rest of the part numbers and descriptions shown in the illustration, I can post those, too.

 

Richard - that's the piece I'm talking about. So, it goes in first? I knew it came in my master, because it WAS in the "used parts" bag.

Now, for the clincher - the old one had a brass washer whose OD was the same size as the ID of the "o-ring", stuck in the ID of the o-ring. Like it was in there originally, although there's no "pocket" for it or anything. Not sure at all why that would have been in there.

When I took it apart, I had it all layed out, figuring I'd just be-bop down to NAPA and get a rebuild kit - didn't happen, had to order one, and in the meantime, the parts got put in a baggie, out of order.

Thanks, I'll put it where it belongs.

Appreciate all the help, folks!! What a place...

R

 

Bill- 2169 - the illustration shows 3 pieces - the "drum", the rubber "cup, then there's another piece, before 2188, that almost looks like a flat washer, or something. Anyone know what THAT is?? I know what 2188 is - that's the big steel washer, that goes in that the snap ring holds all the guts in with. It's the piece at the left-end of the piston assembly...

maybe you CAN post all the descriptions - that would be very helpful, Bill, for posterity..

Thanks again,

R

 

Bill- 2169 - the illustration shows 3 pieces - the "drum", the rubber "cup, then there's another piece, before 2188, that almost looks like a flat washer, or something. Anyone know what THAT is??



I think that is some kind of backer washer that would be in the same groove as ther cup. Should come pre-assembled I would think.