The Stovebolt Site Forums The Shop Area Interiors Floor Access to Dual Master Cylinder

I upgraded to a dual master cylinder in my ‘54 3100 , located in the original place under the driver’s floor.
I am preparing to enlarge the access hole in the floor; the original opening is much too small for dealing with the longer apparatus. I am deliberating the size of that opening… I’d like to get clear on that before I start cutting.

Anyone have experience with that modification?
Input anyone?

I relocated the hole and use the same rubber plug. I can see the fluid level and top off with a small funnel . I use a turkey baster now. Works great

Back when I had my '49, I was going to get a small trap door from McMaster. I sold the truck before I could get that accomplished.

66flea -
My master cylinder looks like the one in the image.
I don’t think I can manage the hold down clips from a single hole location.
Did your master have a different configuration?

You either do the larger trap door or remote reservoir in the engine bay. I’ll tell you since I put a remote reservoir in my engine bay for my frame mounted brake master. I’ll never go back.

Hmmm …
Had not considered a remote reservoir.
How is that plumbed to the master?

Something like this: Remote master for Corvette type master cylinder.

A little different. I use a long screwdriver to take top off and on

On my 46 I cut a new hole and folded the edge over with a ball peen hammer, used a 5 or 6” round SS wall clean out cover (plumbing) with a 1” wide metal strap under it the center screw tightens into ( visible in the photo if you look for it under the lid). The hole is bigger than the stock one so I can just get my hands in there to open and close the MC lid.

Keep in mind with a remote reservior you loose the rubber seal inside the lid of the MC, that seal keeps fresh air out of your MC, which is a good thing for fluid life…

Chuck

The old Brothers Trucks (now I guess Holley) has a "universal master cylinder access door" as well as a "remote reservoir conversion" Kit
https://www.holley.com/products/cooling/parts/RRK4787[uhttps://www.holley.com/products/brakes/replacement-brake-parts/master_cylinder_and_booster/parts/ACCESS-MCconversionrl=http://http://][/url]

OK, sorry how this turned out. The info is all there.

My apologies to my tutor. I guess an old dog like me CAN'T learn new tricks.

S2

Keep in mind with a remote reservior you loose the rubber seal inside the lid of the MC, that seal keeps fresh air out of your MC, which is a good thing for fluid life…

Chuck[/quote]


Yes and no on the remote reservoir exposing air. The really cheap ones with just a vent cap will expose air. But many have the accordion style seal just like the master you have built into the cap or the lid. You just have to look and see which ones do.
Like anything close inspection is the key on this one.

I reused the original battery access panel cover. Happy with the way it turned out.

32vsnake-
By what means did you cut such a neat opening with radiused corners?

1 felt tip marker, some cardboard, a jigsaw, a round file...and some patience.

I myself wondered if you may have used a holesaw bit with the desired corner radius, then cut the straight connecting sides with a jigsaw. Definitely have to plot out your corners to get the rectangle you want, but a holesaw might be quicker/more accurate IMHO.

I used 2 round hexagonal box covers right off the shelf from the electrical aisle at the hardware store. One for the old hole and one for the new hole.

I dont 100% remember but i think I could either access mine through the stock hole or I used the center of the floor access panel to fill it.

I cut a rectangle hole approximately 2-1/2” x 5”, and used a flanging tool to allow the cover to sit flush. I fabricated a cover plate from 18 ga. and flanged three sides to strengthen it. The far side of the cover tucks under the floor and a self tapping screw (not yet installed) will secure the cover.

Phak,
Your sheet metal skills are admirable; they exceed mine.

I cut a new hole with large rounded corners. The hole was cut little smaller than what the finished opening would be then the edges were bent down to help maintain strength. The opening for the transmission regulates the position of the new hole. The down turned edge was rounded similar to the original brake access hole. There will be additional strength added to the floor by installing a 3/4 inch angle iron, 12 inches long, bolted to the side of the transmission opening. The master cylinder access hole will be covered by a metal plate held in place with four screws

How did you bend the edge down in such a neat fashion?

For the sides I used a scrap piece of 1/2" steel plate about 4 " wide by 8" long that had a round edge as a dolly. The width of the plate allowed me to grip it, while holding it in place, close to the edge of the hole. I used a body hammer to form the curve. For the corners I used the round end of a ball peen hammer to slowly tap the edge to the correct size. A body dolly was moved around the edge when slowly, evenly forming the corners. Bending down the edges and using large radius corners maintained the stiffness in the floor. The angle iron on the edge of the transmission opening will increase the integrity of the floor.

Another task accomplished…. Almost.

The pre made access cover us very nice looking, but I decided against buying one because, frankly, I’m tapped out on this truck build and therefore strongly inclined not to buy anything if it can be avoided. I’ve sold off all the toys I can to fund a 2 year frame-off build that I didn’t really plan on , a build that took on a life of it’s own.
But I digress.

The beautiful rolled edge sheet metal work is way outside of my skill set and tool kit. Sure looks good though.

I came up with a piece of steel left over from another project , approx 5” x 6” , maybe 12 gauge, a good stout piece. That made it easy to decide on the size for my master cylinder access port. I cut a hole leaving 3/8” overlap, cleaned up the edge, lined the perimeter with aluminum duct tape to soften the metal on metal contact, drilled and fastened with self tapping screws at the corners and buttabing- done.
Carpet hides a multitude of sins.

In my opening line I said ”Almost”. The almost part is I still need to come up with with a good way to release the 2 spring steel hold downs. I can get the aft one with a screw driver style pry bar , but the angle of attack to the forward one doesn’t allow that. I’ll need to fabricate a special good , which is doable.

My brake fluid level is fine. A nagging task is checked off.

Simple but effective, nice job!

Waveski, that looks good to me, keep on moving forward.

Is that a stick shift with overdrive?

Negative. I’m run a 283 with TH350.
When I got the Frankentruck the steering column was crudely offset to port the allow them column shifter to clear the headers. There were no inner fenders; the hood had been hacked into a tilt job. I wanted inner fenders and conventional hood hinging , and a properly positioned steering column. It got real tight in the engine bay.
The solution was a double U-joint in the column to get the steering past the header and avoid contact with the inner tub , and a floor shifter for the automatic transmission because there was no room for the arms of the regular shifter- they hit the valve cover iirc.

The column is ‘67 Camaro.

Thank you kindly.

I second the 'nice job' on this project. A clean simple solution.

I had a similar problem with mine, and found that a regular brake adjustment tool works perfectly to release the hold downs. It has a nearly 90 degree bend on one end and that allows me to remove and install the hold downs.

Mark

There is a variety of tools used in brake adjustment.
Could you please post a picture of the one you use to release those retainers?

59 fleet-
Is this it?

This is the tool I used. Sorry to take so long to get back to you. The floor opening on mine is probably different than yours but this tool works well for me.

Mark

Thank you, I’ll try that.