I am getting ready to pop my frame mounted master cylinder back into my HEAP. In the past I have had trouble with it leaking over the sides of the bowl. As a result I cannot keep paint on it. Why would this leakage occour? I have a 2 psi valve in the front line for disc's and a 10 psi valve mounted in the rear linefrom drum's as well as the proportioning valve. It leaked both before and after I installed the proportioning system. Should the larger bowl resevoir be for the front or rear and should my pressure activated brake switch be mounted to the larger bowl or the smaller. Any ideas? I havent noticed any trouble in stopping though.
Interesting. I've got the same thing going on in my frame mounted M/C. I've got it hooked up according to the book. Prop valve, residual pressure valves, and even a hold off valve on the front disks. The system works fine other than, like you say, leaking over the sides of the bowl. Anybody have a cure?
[ QUOTE ] I have a 2 psi valve in the front line for disc's and a 10 psi valve mounted in the rear linefrom drum's as well as [/ QUOTE ] Your not running Willwood check valves are you?
I can't remember. They're either Willwood or Speedway. I'll check tonight. Is there a known issue with the Willwood parts?
son of a bitch, i just put 2 willwood 10lb valves in my catalina. seems to be fine now, but how will i know if they fail?
[ QUOTE ] Enjenjo,and some other guys,have reported 100% failure rates on Willwood check valves. [/ QUOTE ] Ian, who's check valves are the best? BTW - Anyone want a "long deal" on a pair of Willwood valves?? (still in the shrink wrap)
Personally,I have no idea. I just remember reading that here,and on RRT,more than once. This comes up often enough,it should be in the TechOmatic.
Well, my residual pressure valves are Willwood but the prop valve is a Speedway. :-( Enjenjo, if you're out there, what brand have you had good luck with?
The Speedway proportioning valve is made by Wilwood. The only difference is that it is purple and says Speedway on it.
Forsaken, why do you have TWO 10# resids in a Catalina? Did you relocate the MC under the floor? Only reason you would need residuals........................................
t-man, i converted the original 1 pot m/c, brake booster to a dual resevoir set up. the new m/c doesn't have built in residuals, and i'm not running any sort of proportioning block, etc, so i put a 10lb valve inline with the front and rear lines. i asked about this a few times over a week ago and didn't get much help, so i just went ahead and did it. seems to work, but if you have other ideas, i'd be more than happy to hear em.
All the resids do is keep the fluid in the wheel cylinders when the MC is under the floor. If your MC is on the firewall still you dont need em.
Actually you do need residual valves with drum brakes, even when the master is mounted on the firewall. And 10 psi are the right valves for drum brakes. The old school master cylinders had the valves behind the seat for the brake line flare. Ok to the in line residual valves. The 10 psi Wilwood valves seem to work fine. It's the 2psi valves I have had trouble with. Every 2 psi Wilwood valve I have used has failed immediately. I have cured the problem on every one by using another brand valve. I have used Sierra, Stainless Steel Brakes, and ECI valves with good results. Another thing with the cover leaking on floor mounted master cylinders, the tin covers are junk, most replacement covers are made offshore and won't seal.You aren't going to like this, but billet covers are the answer, they are stiff enough to not leak. Or you can put a hose clamp around the master cylinder/cover at each end, and hog it down to seal it.
Thanks much for the info Enjenjo. I'll start looking for a new 2# valve and a better cover. I wanted to put speed bleeders on the front anyway so here's my chance. You said the repop covers are junk. would it be worth hitting the junkyards for and OEM cover? Wish I had access to a mill and I'd just make my own "old school" billet.
[ QUOTE ] Actually you do need residual valves with drum brakes, even when the master is mounted on the firewall. And 10 psi are the right valves for drum brakes. [/ QUOTE ] To elaborate on Enjenjo's statement, the reason why rpv's are needed on all drum brake circuts is to prevent air from being sucked in past the wheel cylinder cups, when the brakes are released. The rpv's keep a positive pressure behind the cups, which keeps the cups sealed against the wheel cylinder bores. Mechanical cup expanders are sometimes installed, but they do not eliminate the need for rpv's.
[ QUOTE ] Wish I had access to a mill and I'd just make my own "old school" billet. [/ QUOTE ] Not sure what master you're running. I run a Mustang double M/C with the OEM lid and no problems. Fwiw - the M/C has a stiff spring that requires levering off with a small prybar or screwdriver. My friends run these M/C's as well and no problems reported. The springs are available as replacement parts and perhaps a new one would do the trick. Far as the billet lid goes, you should be able to knock a cover out utilizing a piece of 1/2" thick aluminum. Even 3/8" should work and I wouldn't be afraid of 1/4" either. If you can find the right width, one shot with a hacksaw would do the basics and rounding the corners with a disc or belt sander would work nicely. A small fwiw - I used 1/2" thick aluminum to make a home-made pressure bleeder. Cut the plate to size. Tapped it for 1/8-NPT over both reservoirs. Installed Schrader tank valves*. Used CopperCoat to glue on a medium thick paper gasket. To use: clamp onto the M/C with a common C clamp. (Helps to grind a groove in the clamps movable end pad so it will stay located on the rounded bottom M/C. Make sure both reservoirs are full. Set your regulator to 30# - or run the tank pressure down to that. Get one of the "clamp-on" tire chucks for the Schrader valve. Clamp it on, bleed one wheel from the rear M/C reservoir. Bleed another wheel from the front M/C reservoir. Don't get too carried away and run the reservoir out of fluid, more than likely you won't unless the bleeding is the first time around. Remove cap, fill reservoirs, repeat on the remaining wheels. Top off reservoir and you're done. *Schrader tank valves are 1/8-NPT male fittings on one end and a typical tire filler stem on the other. I you're alone, the clamp-on tire chuck is the way to go, but if you have help a regular tire chuck works fine. This setup does a little better job bleeding brakes than does the pedal and jar bit, but the best part is you can bleed brakes by yourself without getting involved in building a pressurized brake fluid reservoir. The pressurized reservoir would be nice, but for most of us home builder guys, the fluid in the reservoir would go bad over the period of time between uses it would most likely see.
[ QUOTE ] Wish I had access to a mill and I'd just make my own "old school" billet. [/ QUOTE ] You can mill on your lathe. All you need to do is set up a holding device for the workpiece. Most times removing the compound you'll find it obvious what's required. A lot of lathes have cross-slides with T-grooves milled in them already and these really make life easy. A dedicated milling vise for a particular lathe is a good way to go because adjustments are easy to make. Even so, bolting or clamping a piece to a small table adapted to the cross-slide is easily done. Shims work well here. You can clamp end mill cutters in your lathe chuck, but it's hard on them. Better to get an MT adaptor for the mill cutters. There are outfits that advertise in "The Home Shop Machinist" magazine that sell well done castings to make your own lathe and milling accessories. One of their cast tables to convert your lathe for milling is an excellent way to go. I've milled some fairly long pieces in the lathe by finishing one area and then moving the workpiece to another area so the cutting can begin anew there. Best for stuff that doesn't have to be too accurate, but if you take your time the accuracy factor is there. If you have a cross-slide vise for your drill press you can mill stuff there. Trick is to take small bites and don't get impatient. If you get carried away with feeding too fast a vibration will ensue and the chuck, cutter and all will drop out of the drill press's tapered bore. Which leads to interesting results on a used to be accurate piece. Keep in mind as well that a drill press's bearings aren't designed for side loads. Even so, a modicum of care will do it....
Good stuff jay, Thanks! I'm using a 1"bore full sized dual chamber Ford M/C. The stamped steel cover is held on pretty tight but I can see how it might be a problem if it isn't straight. On the aluminum cover I thought I'd need to mill a slight recess to locate it and keep it there. Your saying the tension from the holder spring is enough? If so this'll be an easy deal. I'll certainly put in the Schrader valves. As for milling with my lathe I do indeed need a vise for it. I'd like to find one with a slider I could mount vertically so I could translate up and down. I've looked at a few vises in harbor freight but never got serious about it. My birthday is coming up and this would be a good wish! Are there any internet links to the places with the castings?
c9, i was thinking along the lines kerry asked about. that is, would an oem cover held on by the bale hold the required 30 # of pressure? if so a boneyard cover, drilled, and a fitting welded to it for a schrader valve would do the same thing, right?
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