The Ford Barn

Jrappl · 08-19-2020, 01:26 PM

I have a 1959 Edsel Ranger 292 with the aluminum case Mile-o-matic 2 speed. I'm restoring the car and am cleaning and resealing the transmission.

I got a seal kit for the transmission and everything in it looks right except for one of the servo piston seals. The front servo piston is 3 5/8" in diameter and the rear is bigger at about 3 7/8" but both piston seals in the kit are the same size. Matching the old seals all other seals in the kit are much bigger or smaller.

The new seal size is slightly smaller than the original one I removed from the front piston - the old one could have stretched a little in 61 years and I'm not concerned about this fit. The problem I'm having is using that same size seal on the bigger rear piston. I can stretch it and it's not hard to get it on the bigger piston but I'm worried that being stretched out it might get thinner and not seal.

I called the the kit seller but after looking through all the books they had on hand they said it came in a kit and they don't have a separate listing for the 2 piston seals so couldn't tell me if the seals in the kit would work.

Does anybody have any experience with these servo piston seals? Can I just use the same size seal on both pistons?

rotorwrench · 08-20-2020, 05:59 PM

I've not seen too many Edsel 2-speeds but I have seen the Ford equivalent. The aluminum case 2-speeds came out for the 1959 model year and were used for several years with the 332/352 & 292 V8s and the 223 I6. They gravitated toward the Falcons & Comet cars in 1960 for use behind the small I6 like the 140 and the first of the small block V8 engines. They didn't get vacuum modulation till 1962 like most other Ford transmissions.

I looked up the servo piston seal sets for the Ford-O-Matic 2-speed of 1959 and believe it or not, there are three different part numbers of these sets depending on what the engine application is. The 292 used the B9AZ7A294-B with dimensions 3.689" OD - 3.286" ID - 0.86" thickness and it also shows the same seal for the rear which makes me wonder if the applications might be different. The I6 application is the only one of the three with a smaller size front seal. I wonder if the transmission was ever changed in the past. That application uses the B9AZ7A294-C which has dimensions 3.108" OD - 2.684" ID - .086" thick.

Whether you can cross these over to some other seal or not is unknown to me. At least you can tell that not all of them had the same size servo pistons. It just depended on the application. I just hope you can find some to fit. It would likely have to come from a supplier that knows these transmissions really well.

If Edsel applications are different then a person would need an Edsel specific parts catalog to find numbers.

Jrappl · 09-20-2020, 10:43 AM

The kit I got had the same size seals for both servo pistons even though the pistons are different diameters.

I took the pistons and the seals to a local transmission shop and they were very helpful. The desk guy pulled their top tech out to look. He said the seal looked a little tight on the bigger piston but should be find - just go with it!

I did and we will see shortly, just getting it running now and finding a few problems (hopefully minor) to work through before driving it

dmsfrr · 09-20-2020, 02:44 PM

Are they seals with a more 3D shape, or O-rings?
If there's a shop near you that sells and makes hydraulic and pneumatic equipment hoses they should have selection of O-rings in lots of sizes.

Jrappl · 09-20-2020, 02:54 PM

No, these are square cut o-rings just like the originals. They are supported better than a round o-rings would be and give a bigger sealing surface.

5851a · 09-20-2020, 04:40 PM

Sponsored Links (Register now to hide all advertisements)

I believe they are called quad rings. square seconded O rings.

rotorwrench · 09-20-2020, 06:10 PM

My guess is that they are selling a kit that is one size fits all or at least the end user hopes it will be. Square cross section o-rings are not common like round cross section types are. Hopefully they will last a good bit without splitting due to any extra tension that may be imposed on them.

paul2748 · 09-20-2020, 07:00 PM

There is a trans shop named Fatsco in Pine Brook, NJ that services and sells parts for older transmissions. They may be able to help you.

email - [email protected] 973-227-5414

big job · 09-21-2020, 10:22 AM

If Fatsco don't have it; it did not exist....................

08-19-2020, 01:26 PM	#1
Jrappl Junior Member Join Date: Aug 2020 Posts: 29	Mile-o-matic servo piston seal question I have a 1959 Edsel Ranger 292 with the aluminum case Mile-o-matic 2 speed. I'm restoring the car and am cleaning and resealing the transmission. I got a seal kit for the transmission and everything in it looks right except for one of the servo piston seals. The front servo piston is 3 5/8" in diameter and the rear is bigger at about 3 7/8" but both piston seals in the kit are the same size. Matching the old seals all other seals in the kit are much bigger or smaller. The new seal size is slightly smaller than the original one I removed from the front piston - the old one could have stretched a little in 61 years and I'm not concerned about this fit. The problem I'm having is using that same size seal on the bigger rear piston. I can stretch it and it's not hard to get it on the bigger piston but I'm worried that being stretched out it might get thinner and not seal. I called the the kit seller but after looking through all the books they had on hand they said it came in a kit and they don't have a separate listing for the 2 piston seals so couldn't tell me if the seals in the kit would work. Does anybody have any experience with these servo piston seals? Can I just use the same size seal on both pistons?

08-20-2020, 05:59 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,425	Re: Mile-o-matic servo piston seal question I've not seen too many Edsel 2-speeds but I have seen the Ford equivalent. The aluminum case 2-speeds came out for the 1959 model year and were used for several years with the 332/352 & 292 V8s and the 223 I6. They gravitated toward the Falcons & Comet cars in 1960 for use behind the small I6 like the 140 and the first of the small block V8 engines. They didn't get vacuum modulation till 1962 like most other Ford transmissions. I looked up the servo piston seal sets for the Ford-O-Matic 2-speed of 1959 and believe it or not, there are three different part numbers of these sets depending on what the engine application is. The 292 used the B9AZ7A294-B with dimensions 3.689" OD - 3.286" ID - 0.86" thickness and it also shows the same seal for the rear which makes me wonder if the applications might be different. The I6 application is the only one of the three with a smaller size front seal. I wonder if the transmission was ever changed in the past. That application uses the B9AZ7A294-C which has dimensions 3.108" OD - 2.684" ID - .086" thick. Whether you can cross these over to some other seal or not is unknown to me. At least you can tell that not all of them had the same size servo pistons. It just depended on the application. I just hope you can find some to fit. It would likely have to come from a supplier that knows these transmissions really well. If Edsel applications are different then a person would need an Edsel specific parts catalog to find numbers. Last edited by rotorwrench; 08-20-2020 at 06:27 PM.

09-20-2020, 10:43 AM	#3
Jrappl Junior Member Join Date: Aug 2020 Posts: 29	Re: Mile-o-matic servo piston seal question The kit I got had the same size seals for both servo pistons even though the pistons are different diameters. I took the pistons and the seals to a local transmission shop and they were very helpful. The desk guy pulled their top tech out to look. He said the seal looked a little tight on the bigger piston but should be find - just go with it! I did and we will see shortly, just getting it running now and finding a few problems (hopefully minor) to work through before driving it

09-20-2020, 02:44 PM	#4
dmsfrr Senior Member Join Date: Aug 2012 Location: Abq, NM Posts: 3,607	Re: Mile-o-matic servo piston seal question Are they seals with a more 3D shape, or O-rings? If there's a shop near you that sells and makes hydraulic and pneumatic equipment hoses they should have selection of O-rings in lots of sizes.

09-20-2020, 02:54 PM	#5
Jrappl Junior Member Join Date: Aug 2020 Posts: 29	Re: Mile-o-matic servo piston seal question No, these are square cut o-rings just like the originals. They are supported better than a round o-rings would be and give a bigger sealing surface.

09-20-2020, 04:40 PM	#6
5851a Senior Member Join Date: Oct 2014 Location: NE Iowa Posts: 1,664	Re: Mile-o-matic servo piston seal question Sponsored Links (Register now to hide all advertisements) I believe they are called quad rings. square seconded O rings.

09-20-2020, 06:10 PM	#7
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,425	Re: Mile-o-matic servo piston seal question My guess is that they are selling a kit that is one size fits all or at least the end user hopes it will be. Square cross section o-rings are not common like round cross section types are. Hopefully they will last a good bit without splitting due to any extra tension that may be imposed on them.

09-20-2020, 07:00 PM	#8
paul2748 Senior Member Join Date: May 2010 Location: Midland Park, NJ Posts: 3,980	Re: Mile-o-matic servo piston seal question There is a trans shop named Fatsco in Pine Brook, NJ that services and sells parts for older transmissions. They may be able to help you. email - [email protected] 973-227-5414 __________________ 48 Ford Conv 56 Tbird 54 Ford Victoria

09-21-2020, 10:22 AM	#9
big job Senior Member Join Date: Sep 2013 Location: Dighton, Mass Posts: 1,230	Re: Mile-o-matic servo piston seal question If Fatsco don't have it; it did not exist....................