mk4 willwood cylinders. How to tell which is front and back?

[broku518]

I didn't realized this until tonight. I started working on front brake lines and noticed the manual telling me to use a certain cylinder. I thought that both would be the same.

How do I tell which cylinder is for front and which is back?

[Itchief]

I can’t remember the exact sizes but the largest bore master cylinder is for the front brakes

If you’re master cylinders are both the same size it doesn’t matter which one you use for the front brakes

Also if the clutch pedal hits the 3/4 tube you will have to modify the tube so that the tube will not interfere with the pedal travel

Rick

[BB767]

There are some very small, almost imperceptible, markings on the sides of each cylinder near where the tubing attaches. I think one is .075 and the other is .068. Regardless of the actual numbers, the larger one is for the front brakes.

[edwardb]

As stated, 3/4-inch MC for the front. 5/8-inch MC for the rear. Marked in small numbers on the parts. Factory Five made this change a couple years ago to provide better front/rear brake bias. The smaller master cylinder piston will give more line pressure to the rear brakes compared to the front, something these cars typically need. Note it doesn't matter which side each is mounted on in the footbox. Mount them on the side(s) that provides the best setup for your planned brake line plumbing.

[phileas_fogg]

I work slower than most, and installed the masters long before I ran the lines. I marked each master with a painter's tape label so that I wouldn't get mixed up.

IMG_2755 by jhsitton, on Flickr


John

[broku518]

There are some very small, almost imperceptible, markings on the sides of each cylinder near where the tubing attaches. I think one is .075 and the other is .068. Regardless of the actual numbers, the larger one is for the front brakes.

Yes, I am able to see the numbers. Thank you so much!

[broku518]

As stated, 3/4-inch MC for the front. 5/8-inch MC for the rear. Marked in small numbers on the parts. Factory Five made this change a couple years ago to provide better front/rear brake bias. The smaller master cylinder piston will give more line pressure to the rear brakes compared to the front, something these cars typically need. Note it doesn't matter which side each is mounted on in the footbox. Mount them on the side(s) that provides the best setup for your planned brake line plumbing.

Hi Edwardb,

I was able to locate the numbers on each cylinder. Also, they happened to be in the right place in relation to brake line plumbing. I guess a newbie luck?