Thinking my front brakes were upgraded to disc.

[krumpelsaurusrex]

My master brake cylinder is leaking out of the top, so I went to the parts store to get a new one ($17.99 gotta love the price of parts for these trucks!). It looked a bit big but they said it was the right one. I have a 69 f-250 2wd with 360, and front disc brakes. Sure enough the master cylinder they gave me is to big. ( M1779 http://tinyurl.com/npfvge ). Based on the specs I think this is the one I need. ( M1338 http://tinyurl.com/m1338 ). The odd thing is that I have disc front brakes, and the m1338 master cylinder looks like its for drum front brakes. So I am wondering if the truck originally had drums and was upgraded to disc brakes, and the power booster and master cylinder was left in their original state? What do you think? I don't even know if disc brakes were an option for that year.

If the brakes were upgraded to disc, is it an issue leaving the original power booster and cylinder on?

[fordman]

is it a camper special? if so the brakes are factory. and even if its not i think the f250 did have disc or could have discs on the f250.

[krumpelsaurusrex]

thanks for the reply. I do believe it is a camper special. There are no emblems designating it, but somebody "repainted" the truck and I am sure they did not replace them. Based on the "Safety Reflectors and Tail-light Bezels" section of the "Identifying 1967-1972 Ford pickups FAQ" ( http://www.fordification.com/67-72ID.htm ), I would say it is a camper special. I do have the side markers that are noted in the FAQ.

Strange that all the parts stores would lit the master cylinder as the larger unit. I guess I will try the cylinder for the drum brakes since it seems it may be the right size.

[fordman]

i got the links to work i had to put in your truck specs to get them to work. but the one you bought has a 1 1/4 cylinder bore size and the other one only has a 1 inch bore size. you need the larger bore size from what i know. bore size depends on the correct power to the brakes. did it look like your old one? were both resiviors the same on each one? i think they gave you the right one. is there a number on the bottom of it? what i sit. i have a bad one from a 71 sitting here maybe its the same number. it had factory discs on it. maybe we could compare the numbers if mine has any numbers. or maybe thats a chevy thing with the numbers onthe bottom.

[krumpelsaurusrex]

I am almost certain that the original is a 1". The entire unit is much smaller then the replacement. The main brake line fit, but the second one was to small to fit into the replacement. I am going to have to use an impact gun to remove the bolts, as they are to stiff to remove by hand. Once I do that I will known the correct bore size. But from looks, it seems to big. I'll get back to you tomorrow on any number on it, since I'm at work till late evening.

Thanks for your help.

[fordman]

when i pulled it up by myself with the same part number it said that the smaller bore was for drum brakes. m1338. the other one was for disc brakes. m1779 i do know that the master should or may have came with adapters for the lines. if not you may have to reuse your old ones if it has them.

[flyboy2610]

Thr front discs were not necessarily factory installed. It's possible they were though.
I have a '69 F250CS and it has stock front drum brakes.

[krumpelsaurusrex]

Just a quick update forgood measure on this. I re purchased the m1779 and while it was larger in physical size then the "original" it fit and worked perfect out of the box this time. No. Line adapters were needed. Autozone was the best place to get this from since the other parts houses didn't stock the correct one. Good thing I brought my micrometer with me to check because they all pulled out the wrong ones.

[thebannister8]

krumpelsaurusrex...great user name.....i like that just as much as alfred lord tenniscourt ( or whatever that is )