Built my car using a Corvette 1 inch bore master cylinder mounted under the floor. Great brake pedal, but impossible to check or refill brake fluid. No room at all. Purchased a 1 inch remote master cylinder from a well known street rod brake company, which included the remote brake fluid tanks which mount on the firewall. Mounted everything, tried every possible way to bleeding the master clyinder and brake system, but cannot duplicate the height of the original brake pedal. With the new remote master cylinder the pedal almost goes to the floor. Contacted the company I purchased remote master cylinder kit from and got no satisfaction or help. Looks like I am going back to the Corvette master cylinder. Purchased one of those remote fill aluminum caps that are made for a Corvette master cylinder, but there is not enough room for the remote fill lines which mount on the top of the new cap. Just wondering if it is possible to drill and tap the upper side of the Corvette master cylinder and run my remote filler lines to these new threaded holes. Seems like it should work. Any suggestions or negative thoughts.
Common problem with lots of builds. All of the older cars with under floor master cylinders had an inspection cover in the floor above them for service access. When I made new floor pans for my '40 Chevy I just cut a hole and made a cover just like GM did. To check the fluid I roll back the carpet and expose the access cover. It seems like a lot of trouble but by the time your build is ready for upholstery there should not be any brake problems left to deal with and checking the fluid is at best twice a year. I thought about getting two of the float bowl sight glasses from Holley and drilling and tapping them into the side of the master cylinder. It would be a quick visual check of the fluid level.
I have very little room to check or fill my under-floor mounted MC, but I do it with a mirror and a piece of clear tubing attached to a squeeze bottle.
Access panel - Just Like the factory did it. A Simple solution is the best no matter how complicated you want it to be
Thank for the suggestions guys, but that does not answer my question of drilling and taping a Corvette master cylinder on the side. Part of the problem is my car is painted and I now have two remote filler containers hanging on my firewall. I really don't want to remove them and refinish my firewall. I may just purchase another remote master cylinder from a different company and see what happens. Someone I talked to about the problem recommended I go to a 1 1/16 or 1 1/8 bore size remote master cylinder. I know increased pedal pressure, but it will push more volume and give me more pedal. Anyone know of a 1 1/16 or 1 1/8 bore size remote master cylinder. Thanks again for taking the time to try and help me. Much appreciated.
No you wont. Quite the reverse . A bigger bore MC means a larger volume of fluid is displaced for any given amount of pedal travel. This will result in a harder pedal and less pressure generated at the caliper pistons due to the increase of the area of the MC piston
Pack the reservoirs with rags very well, after covering the holes in the bottom with grease. Drill and tap as each high as you can and still get the cover on. Clean to immaculate. Use hardline, or brake fluid resistant hose. I have done several. No issues.
Before you go backwards, try this. I have a remote fill MC under my 40. Could not get a good pedal and figured I had to find a way to bleed MC. I tried getting the MC level by jacking the rear very high, got it level but still no pedal after bleeding. Finally I took a pair of speed bleeders that I have had in a drawer for a good while, made two lines to connect to mc out ports and used rubber hose to connect bleeders to lines. I connect them to mc, pumped pedal until both lines quit spitting air and fluid flowed. Reconnected brake lines and bingo, got a great pedal.
Seems the original master that worked perfectly and an access panel in the floor would be the best solution. Leave the remote fill there as a dummy. Sorry you drilled holes in a finished fire wall before you figured it had trouble. It doesn't sound like you want to consider that. If it goes to the floor, its has air or its bypassing internally. The bypass can be several issues. There's all sorts of things that need checked when changing masters. The pedal travel, full return, pushrod length, stroke ratio.
I tried this, with a normal mid-70's GM master, the kind that has the bail to hold the cover on. Never could get the cover to seal perfectly, cut hole in floor instead. Cosmo
Thanks guys. Much appreciated. Okiedokie - I will try the speedbleeders as you suggested. What I had done originally was make up some hard lines that went from the remote master cylinder to the tanks on the firewall and had a buddy pump the brakes until no bubbles appeared. gimpyshotrods - Thanks for the words of encouragement that you have taped the side of the cylinder. It is good to know that it will work. cosmo - I am not using the original Corvette master cylinder metal top, but a aftermarket aluminum replacement that allows you to convert a Corvette master cylinder to a remote type. As I mentioned, the holes that fill the master cylinder are on the top of that replacement cap, but I do not have enought room to run the lines to the top of the cap even using 90 degree fittings. I will plug these holes, just using the aluminum cap to seal the Corvette master cylinder. Thanks again, guys.
I did some research a while back and remember at least one MC that had been drilled and tapped on the side for a remote fill. I would say it can be done. Do some more research.
There is no reason the remote mc won't work and be better [imo] than an access hole in the floor. I have the access hole in the floor of my F100, what a pain. Unless you have a bad mc [it happens], you should be able to bleed all the air out of the system.
Good thread - I was thinking about drilling and tapping the MC for a fill line but decided to cut an access hole in my new floor. I think Speedway sells an access panel pretty cheap to make it pretty.. If the system has air, A oldtimer mechanic taught me to get about 50 feet of clear vinyl tubing and cut it into four pieces. Attach each one to the ceiling and the other end to each brake bleeder,open each bleeder, and then pump slowly a few times and refill as necessary. If you push fluid very far up the tubing and are still having air bubbles or no pedal, something is wrong. Go slow and secure the tubing well or you'll have brake fluid everywhere. make sure to size the tubing for a tight fit on the bleeder. I think he had some mason jars or brake cans permanently hanging from the ceiling and some way of attaching the tubing but I just rig some coat hangars on ceiing hooks and safety wire the tubing and go slow. One man system that always worked for me on difficult bleeds.
I do somewhat the same, only one wheel at a time. Run the clear tube up to a jar mounted higher than the wheel, and pump the pedal, slowly. This method has not failed me yet. Cosmo
I use a glass jar, 1/4 full of brake fluid, a clear hose into the jar from the bleeder. Make sure the hose end is in the brake fluid, open the bleeder and slowly pump. Once there's no more bubbles I move to the next wheel, just for added insurance I re bleed all 4 wheels the old way.....works every time. Anyhow back on topic, you could drill and tap the top next to the lid. Use either a pipe tap or o ring base fittings if you tap a straight thread. You could look for a lower profile master. I used a late 60's Chrysler master for my '47 to clear the floor, but it's for 4 wheel drum. or maybe this: Some info: http://www.studebaker-info.org/tech/brakes/36237T/36237T.html
Thanks 1oldtimer, My aluminum lid is exactly like the one you posted, but my fitting came in from the top. Just might have to purchase one similar to what you have pictured. Thanks again for the info.
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