Fill level of master brake cyliner?

[1965c1O]

How full should the master brake cylinder be: specifically for a 1965 with front disk brakes and rear drum brakes?

Does there need to be any "space" in the cylinder for it to work optimal or is that why the cover is rounded?

Also, what type of brake fluid should I be using?

(and why is it so hard to remove the lid - secure vacuum?)



Thank You.

[Lugnutz65]

Originally Posted by 1965c1O

How full should the master brake cylinder be: specifically for a 1965 with front disk brakes and rear drum brakes?

Does there need to be any "space" in the cylinder for it to work optimal or is that why the cover is rounded?

Also, what type of brake fluid should I be using?

(and why is it so hard to remove the lid - secure vacuum?)



Thank You.

I highly recommend getting a Factory Service Manual for your year truck. I also have a 65 C10 and I can't imagine owning one of these trucks without one. You will need to buy the 1963 Factory Service Manual and also buy the 1965 Factory Manual Supplement. That's because Chevrolet kept most of the stuff the same from 1963 through 1966, so they only printed a supplement to add info to the 1963 FSM.

You should use DOT3 brake fluid. Available at any auto parts store.

There is a rubber diaphram (not sure if that's the correct name or not) that sits inside the lid. The diaphram should have fold(s) in it and should fit up inside the lid so that the lid will lay flat on a table.

Fill the bowl almost to the top. If the rubber diaphram is tucked inside the lid properly, then none of the fluid should spill out when you put the lid back on.

The rubber seal inside the lid is probably stuck onto the top edge of the bowl. Wet the tip of a flat blade screwdriver with some DOT3 and try to carefully work it under the edge and get it loose.

One other thing. If you have disc up front and drum in the rear, I'm wondering why you still have an older style reservoir like that. You really need to think about upgrading to a dual master cylinder designed for a disc/drum setup.

[Vernski]

Not a very clear picture hard to see, but I can see it's a single reservoir and I agree with lugnutz65 if you have disc/drum you should have a dual master cylinder plus a proportion valve. The picture is so dark I can't see anything except it's a single, if your having problems with it that could be the reason...Vernski

[jocko]

concur w/above -
- fill almost to the top - maybe 1/8" below the lip.
- ensure that when you put your cap back on that the rubber liner is an "inny" not an "outie" (i.e. make sure it's not sticking down into the fluid, displacing it when you put it on).
- Dot 3 is fine.
- You have an original drum/drum master cyl - as mentioned above, it will not work at all for a disk/drum setup. So either you have a drum/drum setup - or you are not finished with a disk/drum upgrade(?) Also note that just any dual reservoir mc will not fit the bill (for example, a dual res drum/drum mc is available for swap from a 67 impala or 67c10 etc) - the disk/drum mc arrangement has different size reservoirs normally (not always, but almost all aftermarket mc's are like that). And when plumbing it, remember that the forward most mc port is for the rear brakes and the rearmost port is for the front brakes, not the obvious way.