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Hi everybody im bleeding my brakes and pedal wont pump up, im using a vacume bleeder and im getting fluid out of the brake lines.then I found the brake proportioning valve brake lines were all leaking.hard to see the clear brake fluid. So after a coupe hours of using the vacume bleeder and no luck, I hope after tighteng all the lines which I did now no leaks, will try this weekend.I know its probably a dumb question but will that cause the pedal not to pump up , thanks, I hope everybody tell me yes dummy.
Usually the only thing is air in the system. Air compresses and fluid doesn't. Now having said that is the person running the pedal doing it correctly. I have found speed bleeders are well worth the money making it a one man operation with little trouble, assuming all connections are tight and the system is in good repair.
If you changed the master cylinder, you need to bench bleed it first to be sure air is not trapped in the MC. ... And any connection that can let fluid leak out can also let new air leak in. After all the leaks are sealed, then start the bleeding process from the beginning.
I've never had any success using a vacuum pump to bleed brakes.... and it's not for lack of trying. Gravity bleeding has worked a couple of times. The most reliable bleeding technique I've found is to have a helper pushing on the brake pedal while I work the bleeder valves.
I’ve not had much luck with vacuum bleeders either - seems rebuilt calipers often leak too much air around the bleeder screws from worn out threads. A pressure bleeder (Motive) or just a helper to pump the brakes is far more reliable. If you are stuck with a one man operation, then I would invest in some speed bleeders or if not that, pull your bleeder screws and put a little non-hardening thread sealer on the threads and just barely crack them to where your vacuum pump will pull fluid through.
I gravity bled the Wilwood set upon my ‘64 and it worked perfectly. Pressure bleeding would be my next choice as I have also never had good luck with vacuum bleeding.
I second the Motiv pressure bleeder but you need to use a piece of wood and a C clamp to get a good seal vs the chains the send with the kit. I have had good luck with a vacuum bleeder. One was homemade using my AC vacuum pump and the other was using a Mityvac fluid extractor. Key for vacuum is getting a hood seal and keeping the vacuum low.
You mention a proportioning valve. The only thing I can find in your profile is maybe you are working on a 68? Is it 4 wheel discs or front discs and rear drums?
IF the proportioning valve is actually a distribution block with the warning light switch, you have to follow the specific bleeding process to center the piston in the block to bleed the brakes. Just a thought.
I use the two person method with a hose off of the bleeder into a glass jar with an inch or so of fluid in it.
I had to replace all 4 calipers on my '65 roadster.
I bought the fancy deluxe vacuum bleeder..I ended up doing it the old fashioned way..Pump the pedal, open the bleeder screw,close it, repeat...
One thing to note about the 63-65's...The front to rear line sits on top of the frame. If it's original, there's more than a fair chance it's partially crushed. I suspect mine is as the back brakes were much harder to bleed. I'm replacing the line and putting in a dual master cylinder this winter,
To end all of the aggravation I use a large syringe with a rubber hose. I push the fluid in from the wheel cylinder back to the master cylinder. Then do a normal bleeding with the pedal. The master cylinder should be bench bled before installation. I don't know of any way to remove air trapped in a master cylinder.
As others have said, the Motive pressure bleeder is the way to go. Aside from that, if all the lines are drained and calipers / wheel cylinders changed, sometimes the system gets so air-bound it is hard to get the fluid moving initially. You can try opening all the bleeders and slowly pump the pedal a bunch of times with them all open, then close all bleeders and try your normal bleeding procedure again. Sometime that will get things going.
Just to review as I have a 66 Vert that I also converted to a two chambered master. I did bench bleed the master prior to install. Then with the wife at the pedal, bleed the pass. side rear upper (inner 1st followed by outer 2nd I think). Same procedure drivers rear, then pass front then drivers front. Bleed tube is submerged in fluid during bleeding. Remember to stop every 6-7 pumps to check master fluid level, top off as needed. Keep top lid on master while bleeding so as not to splash fluid around. Did no kind of procedure with the distribution block. If the car is on jack stands and wheels off, entire process was done in less than 20 minutes.
Yeah - good, quick approach. Attention span and patience of wife at the brake pedal usually won't exceed 20 minutes.
Love my wife of 40 years, but I don't ask her to do these types of chores anymore - long experience says so - I can tell that her attention span is waning when she starts asking the typical "why are you doing it this way" questions.
Vacuum pump bleeding works great for me on non-ABS cars.
Last edited by Easy Rhino; 09-02-2020 at 08:49 AM.
If you're cheap like me...well, nobody is that cheap, you can build a quick and simple pressure bleeder with a pump up sprayer. I couldn't see spending the bucks for a device I may use once every several years. But forget vacuum bleeding, it's just an exercise in frustration.
Last edited by 65air_coupe; 09-03-2020 at 11:07 AM.
I've never had any success using a vacuum pump to bleed brakes.... and it's not for lack of trying. Gravity bleeding has worked a couple of times. The most reliable bleeding technique I've found is to have a helper pushing on the brake pedal while I work the bleeder valves.
08-31-2020, 10:18 PM
bleeding brakes ,pita
