Technical trouble with new brake system

Hi there.
I have replaced the mastercylinder and power brake booster. I'm trying to bleed the system. I can't seem to get fluid to the wheels. I've taken the lines to the mc off to see if I'm getting fluid from the mc. The new mc has 4 ports. I'm only using two on one side. I have bench bled the mc prior to putting it on. (only the side I'm using. The other two ports are plugged.) with the mc on the car, I've taken the "bench bleed" lines and connected back to the ports I'm using. I seem to be getting fluid thru the lines then. Now that 'i'm having issues, I'm wondering if I need to bench bleed all 4 ports or do I just have a bad mc. Any help for me??

 

I once had a stuck stock proportioning valve couldn't bleed the fronts...
buddy had me buy a new small oil can [pump style], filled it with dot 3, slid a rubber vacuum line over the open bleeder and the oil can nozzle, pumped dot 3 back up to the MC...
but it only worked on one side ? ? ?

 

You need to bleed all 4 ports on the master cylinder.

 

He shouldn't have to bleed all 4 ports, the extra ports just increase the number of applications that the mc will work on and on a hot rod make life simpler for running brake lines.
First I have to ask your exact bleeding method.
Do you have all the bleeders closed and have your helper slowly pumping the pedal until they get a little resistance and then you start by bleeding the furthermost wheel cylinder from the mc brake line wise. Did you have them hold the pedal down until you had the bleeder closed before letting up on the pedal and pumping again?
At sometime in my like I have followed behind someone who has made just about every mistake that can be made with brakes in the past 55 years and I've found many that did not use the proper method for bleeding brakes.

Bench bleeding helps a whole bunch and really speeds up the process but it isn't a total necessity it just makes life a whole lot simpler when dealing with bleeding brakes. That is that much air you didn't push though the lines.

A couple more questions:
Are the brakes if they are drum adjusted properly?
YOU do HAVE the drums on the rig? I went out to look at a guys rig he couldn't get the brakes bled on at the request of a mutual friend and there the car sat on stands with all four drums off and him trying to bleed the brakes.
The bleeders are closed when you pump the pedal?
You do have a helper pumping the pedal and holding it while you go under the rig and open the bleeder and close it while they keep pressure on the pedal? You can't pump the pedal yourself and run around and open the bleeder, it just won't work but guys have tried it.

 

Break the line on the out side of the proportioning valve, do you have fluid there?


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Sloppy J is on to something, forget every thing you know about bleeding brakes. SJ used an oil can I use a syringe, large syringe and push b fluid from the wheel to the MC. I haven't bench bleed a MC in 5 years!
I asked a former HAMBer to come over and bleed brakes in a new project. after a 1/2 hour of frustration he said here let me show you how to bleed brakes! wam bam we were done!

 

I have a hand vacuum pump. I'll give this a shot. But what do you mean it only worked on one side??

 

It's a new proportioning valve, but I've learned NEW doesn't always mean it works. I'll have to look at this too.

 

I bled all 4 ports last night. Once the bubbles were gone, I would lift the tube out of the fluid while my wife pushed on the pedal. The two back ports were squirting about a 1" shot of fluid. I would put the tube back intot he fluid before the pedal was released. The same on the front ports, except they only shot about a 1/4" shot. I'm curious if that seems right. ??

 

Yep. All the valves are closed when the pedal is pushed. When the pedal is down....I will then release and re-tighten the valve. Then my wife would pump it 3 times and hold it while I repeated. Started the furthest from the mc. Barely would have a dribble coming thru on any quad.

I've seen on youtube where they are putting a 2x4 under the pedal to keep it from traveling tot he floor. That will damage the master cylinder??? I don't recall my dad ever having us do that when we helped him bleed brakes.

Drums in the back and disc on the front. I did replace all the drum parts. I've yet to get fluid to the wheel cylinders to challenge that. butI will confirm they are adjusted properly

 

I'm going to try this. In my reply to V8 bob, I mention the amount of fluid coming from the tube when I bench bleed. Do you have any experience to know how much should be pumped out?

 

Check to make sure the master cylinder bottoms out before the pedal runs out of travel, or you will never get a good bleed.

 

Thanks for the reply. I think I've covered your questions in the thread as I'm getting caught up.

 

How would I be able to confirm the mc bottoms out?

Also, I've seen a couple youtube videos where they are saying to put a 2x4 under the pedal when bleeding. I've never done this in all the times helping my dad as a kid. Have you heard of this?

 

Proportioning has nothing to do with the fronts, but metering does, and usually requires pushing a pin or ****on to byp*** the metering valve to allow low ( +/- 100 psi) pressure front brake bleeding.

Total BS. You have to be able to fully stroke the master to purge all the air, along with checking for any pedal bind or travel limits before bottoming out the master.

 

thanks for that confirmation!! I really appreciate any help!!

 

Normally you can hear or feel the master bottom out, but to be absolutely sure.....
Disconnect the master or booster from the pedal and check for any binding or interference while full stroking to the floor. Visually/and or measure the distance between the pedal pad, arm etc and floor.
Reconnect the booster or master, and with both primary and secondary ports open, fully stroke the pedal and compare pedal position or movement with above.

 

If the M.C. is high on the firewall just crack open the bleeders on all 4 corners overnight and let gravity work for you. You just have air in the system and can't get pressure to push the air out.
What kind of 'proportioning' valve do you have?
One spot you can rely on to hold air is the rubber line feeding the rear, you can crack a fitting loose as if it were a bleeder to try to get the air out.
You could rent a vacuum bleeder and that might do the trick, you'll need an air compressor to create the vacuum and it'll pull fluid from the master cyl all the way to the brake bleeder. It has a clear hose and you'll see gobs of air coming thru it.

 

the proportioning valve is an aftermarket SSBC I got from Summit Racing.

 

I need to confirm this. Thanks so much for the help. I need the ideas.
When I attached the pedal to the threaded shaft coming from the power brake booster, the pedal was at it's maximum "up position". I guess I did not confirm that this allowed the pedal to fully stroke the mc. The pedal goes to the floor when compressed. There are many "donor car" parts on this. Anything could be mismatched. Its' part of the fun and adventure of having a Rod. I'll measure the stroke of the mc and then confirm I'm getting this stroke in the pedal.

I put the bench bleeding tubes on the mc while installed to the pb booster. The front ports only squirted a brief amount. I need to check to see what comes out when I have the mc on the bench. maybe I'm not fully stroking the mc. ??? ((along with too much air in the lines when I try to bleed and the loop in the flex piece at the rear.))

 

OK check out a large animal Vet clinic. get a Large syringe, about $8, 2 foot of 1/4" automotive hose. remove cover to the master cylinder. open the bleeder on the back. fill syringe with brake fluid. hose onto bleeder and fill till you think you have fluid "past the T". close bleeder switch to the other side. Fill till you have fluid in master. close the bleeder and repeat the process on the front. DONE!! NO BENCH BLEED needed!!!
Thanks to former HAMB member "rough idle" for showing me how to bleed brakes! He said his grandfather did this 20 years ago and he never knew of the the pump hold system. That's when I threw out my $80 mighty vac.

 

I like it!!! Sounds like the sure way to get it done!

 

Power brakes? do you have the right M.C. for the booster? One with a shallow hole for the pushrod?
Back the 'proportioning' valve out CCW to let full flow to the rear. That type work like the idle adjuster on a carburetor, a needle valve.

 

All adjustable proportioning valves I've seen, have or used require the knob turned CW for maximum pressure to the rear axle, so always re-check the knob for correct adjustment..
Prop valves are not anything like a carb needle valve.

 

If it's this type, it is needle valve

 

the booster and mc were purchased as an ***embly. The mc has the shallow hole. thanks for the thought though.

 

yes, this type

 

You wrote that the pedal was at maximum up position when you connected it to the rod. Is there a little slop before the pedal rod hits the booster? There should be some or the master cyl piston will not uncover the port to allow more fluid to enter the cyl after you let the pedal up.

 

I buy the syringes from Amazon I can get the big one for $10 ( pitch the hose )
https://smile.amazon.com/Yobett-Pla...94886931&sr=1-1&keywords=yobett+150ml+syringe
( once done rinse it out and throw it away as the fluid softens the plastic in a few days and the plunger will stick )

I have a nice gl*** solvent proof 100ml one but was $15 at a surplus store , $25 on line ,

I use these to prefill the brake lines ( make a adapter to keep the fluid from spraying ) to the wheel cylinders before I put the master on with a empty system as you will find out it takes about 1/2-3/4 quart to fill a empty system ( those lines and cylinders have lots of volume ) , otherwise you have to gravity fill the system ( which will take about 4-8 hours ) , or crack the farthest bleeder ( only one open ) and pump slowly, close, return slowly , crack it open and pump again ( over and over about 20-30 times ) , refill the master and keep doing and hope the master doesen't **** the fluid back as the system can air lock/Bind and not allow fluid to move forward thru the lines as it trys to compress the air out plus the meniscus effect ( surface tension ) , and remember do it slowly and after you get fluid at the farthest then bleed the entire system . farthest to closest to the master ..

. pedal should take 3-5 seconds per stroke , do it fast and you can foam the fluid in the master from the return ****ing the air in the lines ( a master will push and **** air better than fluid once its hydraulicly sealed ) and then you have to bench bleed again .
or the best/easiest way, borrow or buy powerbleeder and do it in about a 1/2 hour for all 4 points .

I went to the Brake school Bendix had near South Bend In. at the New Studebaker proving grounds by New Carlisle ( old one was at the plant south of town ) I think V8 Bob was working there when I took it back in the 1980's .. ( we talked about it )