ive got an issue here is the subject 1935 ford w/must II frt susp and stock must II brakes under floor master cyl{typical street rod aftermarket stuff} cant seem to get it to bleed out or master cyl to pump up but....i can use a hand vacume pump and get some of the air out of it i put new hoses and a rt frt caliper on it,becase i thought it was fozen up but no change question is do you all think the master cyl took a dump? or whats you opinion
Has the M11 front end just been put in, or has it been in for a while, and the problem come since the hoses/caliper work was done?? Are the calipers mounted up the right way?? Meaning are the bleeders at the highest point, facing up??
do you have residual check valves in the brake lines,near the master cylinder.these are needed for under floor masters.try bleeding the master first then the system.
this is an older car with the brakes allready in for some time now i started with new hoses first ,they bled fine but rt frt caliper wasnt moving so i thought the piston may be locked , then put on a reman caliper on rt frt but no change. i did bleed down dry a couple of times refllled and started over but it doesnt seem like i am getting any knid of presure up frt and NO i dont think there any any proporsion or residual valve present
i bought mine, it already had a Mustang II in it, after changing the rear to a 9" i found out i cant seem to make the front do much even with residuals installed, the front on my would slow it at best, i'm thinking a wilwood m/c will help, until it comes in i'm lost too
I am not familiar with the master cylinder but typically Street Rod stuff has the residual pressure valves built in. It appears that you are throwing money at it instead of diagnosing the problem and repairing what is bad. Start by pulling the master and bench testing it, will the master itself bleed or make pressure? At first blush I would say that the master has taken a dump. But I am not there to look at it.
Start at the M/cyl. block off the ports to see if you have a high and tight pedal. If not there is no reason to go on. you have found the problem. If you have no pedal clamp off the flex hoses at the wheels. Check for a pedal. Open one at a time and test the pedal to figure out where the problem is. When you lose the pedal you know where to look. I actually had to replace a rebuilt caliper once in order to get a good pedal. It was late Friday afternoon and the customer was due any second. I still have no idea why this calper would not bleed the air out but It went back as a core. Problem solved. Residual valves have nothing to do with the location of the M/cyl. A common misconception.
Try opening one front bleeder a quarter/or half turn. Now slowly push the pedal down, and when you let the pedal up, make sure you go slow. Leave the bleeder open while doing this: Do that 6-10 times, to see if it starts flowing good. If it is, then do the same on other front. if it won't flow when trying this, it could be issues with the master or push rod length, etc.
If I can't bench bleed, I make two loops of brake line that feed right back into the MC wells and keep pumping the pedal until no more bubbles are seen rising in the wells after ten pumps at a time.
No, as long as you are 100% sure the push rod has free play before it hits the master cyl piston, and only if you let the pedal come back very slowly. Nobody seems to want to try bleeding this way for some reason. It works on every one I have tried for 15 years now. Does not seem to matter if the entire line system is empty or half full of air, it always works for me. On empty systems that did not have the master bench bled, then you may need to crack open each line at the master and do the same type of one-man bleeding. When you get steady fluid-only flow at one fitting on the master, tighten that one, then do the other master line. Then tighten and go to one bleeder at a time. "pumping up-hold it down" bleeding on an empty sytem seems to add more air bubbles from foaming, due to rapid pumping. It is not needed in any case i have seen, and I do many older cars/trucks by myself. P/S I never bench bleed. and I never fully depress a master. It's just how I do things, it's not in any book.
You did not say if this was a power booster setup or not but I don't think your rod is long to press the piston in far enough to create the pressure you need. Take the master off and have some one depress the brake. measure the amount the rod extends then measure the distance to the end on the hole in the master where the rod fits into. If it only will push it in a small amount it is the length of rod. If it goes in until it bottoms out then I would say you have a bad master...Other wise lengthen the rod. Good luck
Block the master cylinder with a plug and see if it builds pressure. Caution do not push the master cylinder piston all of the way down it can destroy the master cylinder only abount an inch.
had the same problem on the new car, all of the above comments are important, but there is a rod between the mc and the power booster, it is adjustable the adjustment was very important, also we changed the ratio of the pedal to mc rod movement it seems to work the ems guy
had the same problem on the new car, all of the above comments are important, but there is a rod between the mc and the power booster, it is adjustable the adjustment was very important, also we changed the ratio of the pedal to mc rod movement it seems to work the ems guy
totally agree...bench bleed the master. sometimes I'll push till the pistons pop out a bit and sand them with a fine grit paper and lubricate them. Also, I just recently saw somebody using an air operated bleeder kit...makes it wasy to bleed brakes with one person!
SPeaking of bleeding.. I'm sure you can get them too, but Napa here sells bleeder fittings for wheel cylinders, that have a one way valve. you can leave them open to bleed, and they won't allow air back in. Very handy and not expensive.
if you changed out caliper and no change, pump up system and crack system where rubber line going to caliper from steel line. bet you have a collapsed rubber line. the brake fluid eats them after sitting for extended periods.
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