Thread: Drilling holes for thru frame brake fittings

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I'm ready to start running the brake lines on my 32 frame. I need to locate the points where the bulkhead thru frame fittings need to be drilled for the front hoses. Is there a 'rule of thumb' where these need to be drilled?

Thanks, Steve

Every car is different, but generally you want the fitting to be as much in line with the port where the hose enters the wheel cylinder or caliper as possible. What you are trying to do is keep the hose from getting pulled tight as you make a turn one way and from having too much slack when you turn the other. You also want to make sure the hose will clear things like headlight mounts, drag links, shocks, etc. when turned sharp each way.

What you might do (if you don't have your brake hoses yet) is rig up something like rubber fuel hose and temporarily hold it to the wheel cylinder and several spots on the frame to see where it will swing the best when you turn the wheels from one side all the way to the other.

It might help if you post some pictures of your setup so we can visualize better exactly how yours is set up.

Don

Thanks for the advice. I have all of front suspension installed and disc brakes but I haven't installed the calipers yet. I will put them on in the next couple of days and take some pictures.
What's your opinion of master cylinders? I'm running 9" drum rears and disc on the front. (Non-power)Corvette or Mustang or what? I really like the looks of the Speedway aluminum master cylinder but it's kind of pricey.
Thanks, Steve

I will be using a Wilwood with a 1" to 1 1/16" bore on mine in conjuction with a GM disc/drum proportioning valve. ( at least this is the game plan for now )

Good advise from Don. I found that it was best to mount caliper and hose and move spindle through full turning motion while holding hose end in different locations until I found where hose cleared everything and didn't try to kink. It did not end up being mounted where I had expected. The hose length will influence where you mount fitting, so keep this in mind. Hope this helps.

I do mine a LITTLE different.

I like to use thru the frame fittings on the front.



I also like to run braided AN lines



I have the caliper mounted and the correct fitting in the caliper.



I then take a piece of rubber hose and " mock up " the line. I can then figure out the BEST place to install the thru the frame fitting and order the correct lenght braided line ( with AN fittings ).

_______________________________________________

On the rear, I use a pair of these ...



Held in place with a clip ... after the bracket is welded to the frame.

Then I can install the AN fitting in the rear wheel cylinder and determine to correct length braided line for the rears.



Ray GodmanHigh Performance sells all this stuff. He sells everything needed ( tools also ) to do a good, neat job. It is not the CHEAPEST way to do this ... but when dealing with BRAKES ... cheap is NOT A OPTION ... IMHO

I do mine a bit different.

Rears:


This is an aluminum bracket I bade up with a bulkhead fitting recessed into one side and held to the frame with SS socket head caps, again recessed into the aluminum block. The line is then connected to the Wilwoods via a Russell DOT 90* approved flex line.

The fronts:


Pretty conventionally done with the fitting about in line with the Wilwoods and again connected via a Russell DOT line (Deuce, I do like that front fitting instead of the Speedways I have, but.....)

If the master cylinder is hidden under the floorboards, IMHO, why spend big bucks for a fancy shiny version - save the extra $100+/- for something that can be seen unless you 'have the need'

Oh yeah, something to consider on the calipers - speed bleeders. One man brake line bleeding. You need two for each Wilwood though, so it does get somewhat pricy if you have 4 wheel disks

Some how ended up w/dupe post

I am running manual disc/drum set-up. Does anyone have the part number or know which Corvette/Mustang master cylinder I need?
I don't need fancy (since it's frame mounted on the 32) but I would like one with the ports on the frame rail side instead of the opposite or a universal.
Thanks, Steve

Originally Posted by IC2

Some how ended up w/dupe post

Freudian slip?!?!?

Originally Posted by 34_40

Freudian slip?!?!?

Nahh - just a senior moment and a shaky posting finger

What size hole do you drill for thru frame fittings ?

Originally Posted by 32highboy54

What size hole do you drill for thru frame fittings ?

It would depend on WHICH fittings you plan on using.

I believe I would get out the micrometer and measure the diameter of the fitting and then drill slightly larger

Originally Posted by Deuce

It would depend on WHICH fittings you plan on using.

I believe I would get out the micrometer and measure the diameter of the fitting and then drill slightly larger

I agree with this - mine are 1/32" larger then my fittings which are Billet Specialties. Cances are that you can't drill the hole straight and this allows a bit of slop. I also put a SS flat washer under each side for just a bit more bearing area and so it wouldn't dig up the paint, now powder coat. You can just barely see that washer on my front end photo above.