69 brake master, anyone know the difference btwn 40 or 55? (1 Viewer)

[bigsal]

I m looking at getting a 1969 brake master cylinder for my clutch for my fj55 sbc. I have seen that there is a difference between the fj40 and fj55 model masters for sale. I can't see the physical difference in those units. Found one for an fj40 that is much cheaper than the ones for the fj55.

Anyone know what the difference is? Any reason why I couldn't mount the one from an fj40 into my fj55? They both appear to have the same bolt pattern as my 1972 fj55 clutch master.

Thanks!

 

[3_puppies]

2 things: if you are still using a single circut brake system, you really should upgrade to a dual circut system. Mark A and Georg E have an adaptor plate to mount a dual master in place of your single master.
I think the 55 master has a bigger bore, I know the rear brake cylenders have a bigger bore for more stopping of the wagon versus the 40.

 

[bigsal]

2 things: if you are still using a single circut brake system, you really should upgrade to a dual circut system. Mark A and Georg E have an adaptor plate to mount a dual master in place of your single master.
I think the 55 master has a bigger bore, I know the rear brake cylenders have a bigger bore for more stopping of the wagon versus the 40.

Thanks for the reply, but what I am doing is using the 69 brake master as a clutch master for my SBC conversion. My stock clutch master just ain't got the guts to move that fork enough. I have read several post about people using the brake master from a 69 as a clutch master because it has a 1 inch bore, as opposed to my current 3/4 inch bore.

For the record, I've got dual circuit with disc conversion.... very nice.

 

[BROKEN WRENCH]

i have used one for over a year now with no problems. plenty of pressure plate travel now. before my clutch wouldnt release half of the time

 

[bigsal]

i have used one for over a year now with no problems. plenty of pressure plate travel now. before my clutch wouldnt release half of the time

Yeah, that's the situation I'm looking for. I just see that some folks sell one for fj40 only and some for fj55 only for that year. The pictures of them look the same. There seem to be two different models though. I ordered the one with the big brass nut looking thing at the end where the tube screws in. The other model I have seen does not have the nut. I have seen them both (types) separately labelled as for fj40 or 55. It must be the same thing. SOR lists a separate one for the fj55 but they don't show a picture. I can't see what would be different given that they were both a single circuit. I am guessing that they were both a 1 inch bore. They both have the same three bolt pattern too. Got a picture of yours?

 

[bigsal]

Just got a response from SOR. FJ40 version has a 9 mm fitting and the FJ55 version has a 10 mm fitting.

 

[AZMoonshadow]

I still have the single circuit brake system (9mm), and would love to convert. Who is Mark A and George E?