62 impala, switching from single manual to dual power. Drum drum setup. Getting no pedal. when bleeding the rear, fluid just barely dribbles out. Front is better but still absolutely no pedal. master cylinder had been bench bled and this is the second setup from the auto store. ***umed the first one was bad so we went ahead and swapped them out for a new one, but to no avail. Any ideas?
So you added a booster. Do you know for sure if there is freeplay between the pushrod at the end of the booster to go into the master? If it has no play and is not letting the piston return, it will not bleed right. Also, how are you bleeding it? I open one bleeder and just very slowly work the pedal up and down till I get good flow, then go to another. It never failed yet , doing it this way. You can even put a rubber hose on the end of the bleeder to have it in a gl*** jar with some fluid, to watch for air.
think f&j has it sounds to me like master cyl piston not returning to rear most position alowing fluid into ports then moving only part way forward is the little metal rod in the booster between booster and cyl too long or missing
the booster and master cylinder came as a kit already together, so I would hope that the pin between the mc and booster is correct. Now the the pedal to booster I'm not sure about.
l've converted several 60's Chevys to power brakes. The pushrod always needed to be lowered about 1" on the brake pedal. Usually there is a second hole on the pedal for the push rod pwr brakes system.
yea, mine is in the top hole. Will that cause these symptoms? I guess if it's not actuating correctly than I wouldn't be able to bleed the brakes correctly either
First things first, drop down to the lower hole...........................it worked on a '64 Impala I did, think it was even mentioned in the instructions!
This is probably the only time I have disagreed with what F&J had to say but opening the bleeder and pushing the brake pedal with the bleeder open is going to **** just as much air back in as you push out. The hose in the bottle thing works as long as you have the end of the hose in brake fluid so that you **** brake fluid back in instead of air. It doesn't beat having a helper "pump it slow and hold it" while you open and close the bleeder screw though. I'm like the others in that you need to drop the pushrod down to the lower hole and that should give you a bit longer stroke.
Dropping the rod to the next hole ..... That's changing the pedal ratio; it will increase the stoke on the pump rod for the same amount of pedal movement. In exchange for this you need greater effort thru your foot but the booster helps with this. Depending on the geometry of the pedal, it may even return farther and that will be the phenomena fj spoke of
If the end of the hose is open, it will **** air back in as soon as the hose rises out of the fluid in the jar, and it will rise out all the time. My dad taught me a trick for this - use a rubber hose as per normal, plug the end with a suitable screw/bolt, and then make a 3/8inch slit in the side of the hose with a craft knife. The fluid will pump out, but the slit closes itself up and won't let air back in. It's a cheap/free alternative to 2man bleeding, or other bleeding contraptions.
How were the brakes before you started this? I didnt see it mentioned anywhere, but if they are 1962 all original lines and wheel cylinders, then you might also need new lines and cylinders. They arent that difficult to replace and should be if you havent. Chain only as strong as the weakest link and all...... If you have, then I return you to your regularly scheduled programing.
brakes were fine before this. Some lines have been replaces as well as all the wheel cylinders. It's my daily. I've lost the brakes when I was younger and a wheel cylinder went. I'm getting too old for that **** and the car was supposed to come with me to Oregon next month, so I started some upgrades. As it stands now, I may sell the car. And regret it later. I will try the lower hole tomorrow and hopefully all will be well. Thanks
Alright, I moved to the lower pin per everyones advice and no change. Still no pedal. I'm going nuts here!!!
Try this if you have not yet.. Loosen the rear line fitting at the master cyl about 1/2 to 3/4 turn. Sit in the car and slowly push the pedal down about 3/4 of the full stroke. Now, when you let it come back up, do it very slow. Keep doing this till you see/hear fluid coming out. If you can't get any decent amount here, after say, a few minutes, try the front line at the master. If you still get no flow, there very well could be a problem with the master pistons not coming back far enough to grab fluid. So if it goes good,and you finally get some decent flow going there, work your way back to any fitting or union in the line going back to the rear/ If there is none, loosen one rear bleeder and do the same push/and very slow return. You should eventually get it to flow. Might take a while if the entire ststem has no fluid. Sometimes on real *****y cars, I have to start with the front line fitting at the master, then go to the closest front wheel.
Like Hotrodchevy said.Check the pin between the booster and the master cylinder.If it is too long the master will not return .Look in the reservoir on the master cylinder.Have someone push the brake pedal.When they let go, fluid should bubble out of the two little ports down in the bottom.If no bubbles pin is too long.I ran into this before on a cylinder and booster bought ***embled.Good luck,Don`t give up yet.
Moving the push rod down to the lower hole changes the pedal ratio from about 6:1 manual to about 3:1 for power, which is correct. Make sure the pedal can bottom the master cylinder pistons before it hits the floor. Perform this with both systems open and no vacuum in the booster. Make sure all fittings and connections are tight. The technique when bleeding can sometimes be the problem. You want to slowly and fully stroke (not pump) the pedal while bleeding each cylinder. (again, the pedal MUST full stroke the master BEFORE the pedal hits the floor!) It's best to use a 3' or so length of clear Tygon tubing pushed over the bleeder, coiled up slightly higher than the cylinder, and then empting into a container. This allows several inches of a good visual flow of fluid and air coming out of the bleeder. The bleeder should only be opened enough to have a slow steady flow, and then shut when the pedal bottoms out. The person stroking the pedal should hold it down until the bleeder has been closed. Good communication between the pedal pusher and bleeder is important. When some pressure can be developed, do a leak check by applying high (max) pedal force. If the pedal remains solid and does not move to the floor, and there are NO leaks or weeps, repeat the bleeding process two or three more times per wheel until only clear fluid comes out of each bleeder. It doesnt matter which wheel or system is bled first on a dual system. Just check the fluid reservoirs often. If you are confident of a good bleed, apply vacuum (start the engine) and repeat the leak test by applying max pedal force. Use isopropyl alcohol to clean all the connections, fittings, as well as tools and spillage on the vehicle and your hands. Using a spray bottle makes it very convenient. You will find the alcohol makes finding leaks and weeps much easier, and does a great job cleaning up fluid messes. To check the booster push rod clearance, apply full vacuum (about 20" HG) to the booster with the master removed, use a small amout of clay or similar pushed into the master cylinder primary piston, and bolt on the master, then remove and measure for .040"-.050" push rod clearance, and adjust if necessary. Make sure the brakes are properly adjusted, or you'll never build good pressure. Hope this helps.
OK, so here's an update. I opened the MC and pumped the brakes. The front bowl pretty much shoots fluid right out of the bowl. The back bowl has no movement what so ever. Also, The front bowl, the fluid was completely murky and the back bowl was perfectly clean. Bad MC?
thought you said purchased together,arn't they both new? (master and booster) hardly seems possible for front piston movement without rear piston moving as they move together rear first as far as i've seen. I guess its possible you got a bad master in the mix but most parts go through a pretty good QC before leaving factory.
first time around was a good booster and we bought the mc separately. We returned that and got a kit but they would only give us a reman kit. It's from advance auto parts and I've heard there reman stuff is ****. As far as the piston movement, I have no idea. I am doing this myself in my driveway. Would what I described be a BAd MC? What would cause the murky fluid?
Have you started from the beginning after all your trying maybe you should start over and first bleed mastercyl alone establish a good flow and preasure then move on to the lines checking all conections and bleed as usual
May have to do that. when bench bleeding the first time, It seemed the back wasn't flowing at the same rate as the front. Which makes me thing bad MC again, but I was really hoping not.
Don't want to bad mouth any body but in my shop we see all typs of meman defects from every source. could well be bad those type parts tend to be prone to shabby rebuilding try buying one from a reputable local auto part supplier or if you have a good used one that you know is good try that you can change it easy later.good luck hope you get itsoon these things can drive you nuts.
I'm trying one more tomorrow, if it's bad then I am getting my money back and going somewhere else. Thanks for all the help. I'll let everyone know what happens.
Murkiness might be caused by pumping to fast, I believe the mc is bad, the orifice that feeds the rear brakes is plugged or defective
Im sure this is just wasting your time and Im Not trying to insult your intelligence, but, Are you using one of the kits that pushes the spent fluid into a little bottle so it cannot **** air back into the system...it must **** fluid back in?? Also, Are you bleeding the brakes correctly? Pump up till you get a good pedal, then have a buddy open the bleeder and close it... before letting back up on the pedal? Are all 4 wheels pushing fluid out like they should when holding down on the pedal? Here is a quick link that might help. http://www.popularmechanics.com/cars/how-to/maintenance/4213448 It could also be your parts. I had a heck of a time with my headlight switch before changing to a Chevy style and it wired up fine and works fine. I think I got a bad switch...brand new.
Bleeding is done correctly, using two people. However, the pumping till you get pressure part isn't happening. Hence the problem.
Loosen the master from the booster and see if the fluid bubbles up from the rear port.If it does the pin is too long.
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