Thread: Master Cylinder?

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Stainless is pretty hard stuff, it won't deform to the fitting as well as steel will.

Thanks to you all for the precautions, I am well aware of the need for a perfect brake system and I especially value Tech1's comments. First, Brian, I did have all the lines double flared at 37 degrees. Second, part of the problem is that the through-the-chassis tubes have an AN-3 fitting on the outside for the braided flex lines to the front wheels, BUT (!) on the inside of the frame there is only a tubular hollow female pipe thread with no shoulder except way, way deep inside the other end at the inside of the flex hose fitting. I confirmed this with the tech guy at Speedway. I am referring to Speedway part No. 910-31360 for a 1 3/4" thick tubular frame. I don't want to change now since I have cut a 1" diameter hole through the frame. Maybe I can try to set the threaded male end deeper into the tube, but I don't think it is long enough. The Speedway tech guy said to use pipe sealer but so far I have not found a sealer which will set up. A call to Bebops from whom I purchased the master cylinder said to use a teflon sealer that will set up like a glue but again I do not know what brand to look for. By now I have actually obtained a seal on almost all the AN-3 fittings by tightening them a LOT using the usual special box wrench with a slot. In those cases where I have tried to refit them I have examined the tips of the male ends and found them to be indented. It would seem to me that part of a good seal is to squeeze the male end into the double-flare 37 degree cones but there must be some limit as to the strength of the threads in the outer fitting. I had to work a half day today but I spent the afternoon and part of this evening on the problem. My progress so far is that I removed the MC from the chassis and put it in the vise and then with a lot of elbow room to work it was easy to get the bung out of the plug hole. Then my friendly (and sometimes expensive) NAPA rep sold me some steel plugs with hex heads and the 1/2" plug fits the hole nicely but I have not reassembled it because I want to put the same type of plug in the other hole in the morning so as to avoid any use of teflon tape. With a 1/2" hex nut to wrench on I should be able to tighten these plugs for a good seal and they are only about $0.40 each so if I strip one I can get another easily. If I can get these last three leaks sealed (out of about 20 or so joints) I will stay with the stainless system, but I am hearing you and may have to scrap it and go back to regular steel tubing. At this point I do not care if the tubing is shiny, the most important thing is that it be safe and reliable! Thanks to all of you! Actually this Forum is very valuable to a guy like me in the sense of safety issues and Tech1 is invaluable as to on-line tech inpection and no doubt Brian made a schrewd choice using the regular steel lines. As I recall at the time I bought the stainless tubing and AN-3 fittings I had just replaced two (2) leaky steel lines on my '93 Ranger pickup and my reasoning was that if those lines corroded in 12 years I ought to use stainless, but of course the main problem is that most of my rodding experience has been limited to just changing engines and this is the first "full-build" I have attempted. I really appreciate your help in this matter and if/when I get it sorted out I will let you know, maybe in a day or two! By the way I tried to saw an "easy-out" shorter so I could squeeze it in a tight space, but don't try it, my hack saw wouldn't even scratch the surface of the hardened easy-out so that is why I pulled the MC out of the chassis to work on it.

Don Shillady
Retired Scientist/teen rodder

Well sorry to bother you folks and expose my ignorance at the same time, but I think I have a good ending. I removed the MC from the chassis and put it in my vise and got the bung out by using a screwdriver as a chisel tangentially on the edge. Anyway I took the bung to my guru Joe Butler at Joe's Machine Shop. Joe is an amazing person of a few good words and he said "You got to have the right tool." and he produced a T40 torqx socket which still fit the bung even though I had pretty well messed it up using an Allen wrench. So I bought a set of torqx wrenches (as suggested by lts10) and put some "umph" on both plugs and reassembled the setup on the chassis. I still have to bleed the brakes but so far with lots of pumping I see NO LEAKS! Joe says he is retiring and moving his shop machines to his home garage where he will work on his '55 Chevy two-door. Joe also asked about lts10 and I told him I only know that Mike is still active and can still type (and he also spotted the problem with the torqx socket)! Thanks to all who responded, but it is helpful to have an experienced track racer with a machine shop close at hand!

Don Shillady
Retired Scientist/teen rodder

DennyW, you have been helpful to me on several occasions and quite a few members of this Forum have provided real expertise to me a number of times. In my previous profession I had a special set of tools to work on optical and electronic equipment, but somehow I had not encountered torqx wrenches before! Well I don't want to wear out my welcome here but I will probably be back with the next problem in a week or so and my '29 may end up being built by Forum members but in my garage. Some of the regular responders here and Joe Butler locally have my respect for their combined practical experience. At this point I am beginning to worry whether I will be able to reach a level of decent appearance in my final car so I will try to keep it simple and just plain '50s in appearance related to a time when rods were often only slightly modified externally, but I will work on it to try to get someting that looks clean and simple.

Don Shillady
Retired Scientist/teen rodder

Don, i have a feeling if you don't reach a level of decent appearance then the car will never see daylight. if i have to I'll load up the old o2 bottle and come to Richmond. if Joe close down he only live a few miles from where his shop is. he lives off of Staples Mill Rd.(rt.33) and Springfield Rd. just south of 295. the last time i was at Joe's house i had a 1980 el camino that one of my ace mechanics had just built the motor in and the motor was a little hard to turn over when it started so he said drive it, it would work itself out. so that night I'd had a few to many and the wife was driving and when we left Joe's house i told her to put it to the floor and id do the shifting, so she ran it up to about 6000 rpm's and when i shifted to second a rod came lose and knocked a hole in the block that you could put your head in. i told her to keep on going and she drove it back to the shop (about 15 mi.)with no oil and knocking like you wouldn't believe, but we made it. pulled the motor back down and every rod in it was backwards, so if somebody tells you, you can't run a 350 chevy. with the rods in backwards, tellem you know dif. its just makes it a little tight.

those torx sockets will come in handy on some of your late model stuff.

Today I am going to give the brake system one last check with a final bleed of the lines and then hope that I can move on to the trans cooler. I have built a battery bracket from angle iron and installed a battery box from Speedway on the very back of the frame and measurement says it will just clear the back edge inside of the Model-A body, although I may have to cover it with some sort of roll pan. lts10 you remind me of a story about my younger brother who took an Austin Healy roadster on a trip up to New York and was many hundred miles from home when a rod failed. He went to a gas station lift and pulled out that rod from the bottom and somehow also took the piston out after taking the head off and drove it over 300 miles on 5 cylinders. I also had a Blue Flame Chevie 6 in a '54 Bel Air convert and a rod poked through the side of the engine because I had the valves ground but not rebuilt the bottom bearings. I noted the engine was still idling on 5 cylinders so I drove it home another 15 miles and the next day it started up and I drove it to Sears for a rebuilt engine. I hope I don't have that kind of trouble with my 350, but as you say it wont be the first time!

Don Shillady
Retired Scientist/teen rodder

Originally posted by Don Shillady
Today I am going to give the brake system one last check with a final bleed of the lines and then hope that I can move on to the trans cooler. I have built a battery bracket from angle iron and installed a battery box from Speedway on the very back of the frame and measurement says it will just clear the back edge inside of the Model-A body, although I may have to cover it with some sort of roll pan. lts10 you remind me of a story about my younger brother who took an Austin Healy roadster on a trip up to New York and was many hundred miles from home when a rod failed. He went to a gas station lift and pulled out that rod from the bottom and somehow also took the piston out after taking the head off and drove it over 300 miles on 5 cylinders. I also had a Blue Flame Chevie 6 in a '54 Bel Air convert and a rod poked through the side of the engine because I had the valves ground but not rebuilt the bottom bearings. I noted the engine was still idling on 5 cylinders so I drove it home another 15 miles and the next day it started up and I drove it to Sears for a rebuilt engine. I hope I don't have that kind of trouble with my 350, but as you say it wont be the first time!

Don Shillady
Retired Scientist/teen rodder

you'll be alright with the 350. I think with most of us Don it is a matter of doing what needs to be done to get the job done.

DennyW, if you mean the dimension diagram for the Model-A Sport Coupe, YES, please send it to me because I want to make the rumble-seat gas tank as close to the original rumble seat as possible. Please send it to me by e-mail and I will appreciate it very much. I have spent most of my holiday weekend making a cardboard mockup of the tank. It certainly is true that it is better to make a mockup than to just draw what you think you want or need. I must have made ten different modifications once I tried to fit the mockup into the space and in particular I had to downsize it a bit to only 13.8 gallons but that should be enough to make it to Va Beach and back on a weekend if I can get about 20 mpg with the R700 OD. Thanks for the armor plate idea, I have bolted in a 4" wide 1/4" steel bar across the back framework of 1" square tubing in the fiberglass body just behind the gas tank with a 2" clear space between the bar and the tank and it does all tuck in with the deck lid in the rumble position. I will send it to Rock Valley to make up a stainless steel version of the tank and it won't be cheap but at least it will clear the bumps in my rough driveway. Thanks for the suggestion. I have left room for foam padding and vinyl covering so the dimensions of the seat will be useful, particularly the thickness of the back rest and the height of the seat at the back. I have left room for up to a 4" wedge of foam down in the lumbar area in the back of the seat but I need to know the approximate slope of the seat bottom.

Don Shillady
Retired Scientist/teen rodder